Pressure-based physiological evaluation of coronary artery disease is well established, but its application is limited in left main coronary artery (LMCA) disease. Our aim was to investigate whether pressure-based indices are comparable in the left anterior descending (LAD) and left circumflex artery (LCx) branches of the LMCA, and if discordance is due to differences in microvascular function in these territories.

Simultaneous measurements of coronary pressure and flow were made in patients with (1) isolated LMCA disease and (2) unobstructed coronary arteries. Fractional flow reserve, instantaneous wave-free ratio, and microvascular resistance reserve values in the LAD were compared with those of the LCx.

A total of 80 patients were enrolled (mean age 65±10 years, 56% male). In those with isolated LMCA disease, fractional flow reserve in the LAD was lower than in the LCx (0.74±0.11 versus 0.81±0.11; P<0.0001). Instantaneous wave-free ratio was also lower in the LAD (0.89 [0.76-0.92] versus 0.94 [0.88-0.97]; P<0.0001). The misclassification rates of functionally significant coronary disease, when these indices were measured in the LCx, were 21% for fractional flow reserve and 28% for instantaneous wave-free ratio. Microvascular resistance reserve was higher in the LAD than the LCx, in cohorts with diseased (3.57±1.40 versus 2.50±0.81; P<0.0001) or unobstructed LMCA (3.40±0.78 versus 2.47±0.68; P<0.0001). Microvascular resistance reserve in the LAD territory was similar regardless of whether the LMCA was obstructed or not (P=0.56). Similarly, microvascular resistance reserve in the LCx territory was comparable between cohorts (P=0.88).

Microvascular resistance in the LAD is lower than in the LCx territory. Consequently, fractional flow reserve and nonhyperemic pressure-derived indices are lower in the LAD than the LCx. These findings have important implications for how LMCA atheroma should be assessed in clinical practice and also suggest the need for territory-specific thresholds for defining abnormal microvascular function or epicardial conductance.

Intracranial atherosclerotic disease (ICAD) significantly increases the risk of ischemic stroke. It involves the accumulation of plaque within arterial walls and narrowing or blockage of blood vessel lumens. Accurate imaging is crucial for the diagnosis and management of ICAD at both acute and chronic stages. However, imaging the small, tortuous intracranial arterial walls amidst complex structures is challenging. Clinicians have employed diverse approaches to improve imaging quality, with a particular emphasis on optimizing the acquisition of images using new techniques, enhancing spatial and temporal resolution of images, and refining post-processing techniques. ICAD imaging has evolved from depicting lumen stenosis to assessing blood flow reserve and identifying plaque components. Advanced techniques such as fractional flow reserve (FFR), high-resolution vessel wall magnetic resonance (VW-MR), optical coherence tomography (OCT), and radial wall strain (RWS) now allow direct visualization of flow impairment, vulnerable plaques, and blood flow strain to plaque, aiding in the selection of high-risk stroke patients for intervention. This article reviews the progression of imaging modalities from lumen stenosis to vessel wall pathology and compares their diagnostic value for risk stratification in ICAD patients.

Fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) are discordant in approximately 20% of cases, and it is unclear whether this is influenced by the physiological pattern of coronary artery disease (CAD). The pull back pressure gradient index (PPGi) can objectively characterize the physiological pattern of CADs.

The aim of this study was to evaluate whether PPGi differed in discordant groups (FFR+/iFR- vs FFR-/iFR+).

The study enrolled 355 patients (390 vessels) with chronic coronary syndrome who had ≥1 epicardial coronary artery lesion with 40% to 90% diameter stenosis by visual assessment on invasive coronary angiography and had analyzable FFR, iFR, and PPGi derived from quantitative flow ratio. Cutoffs for hemodynamic significance were FFR ≤0.80 and iFR ≤0.89. Vessels were classified as FFR+/iFR+ (n = 103 [26.4%]), FFR-/iFR+ (n = 27 [6.9%]), FFR+/iFR- (n = 38 [9.7%]), and FFR-/iFR- (n = 222 [57%]) groups.

Median FFR, iFR, and quantitative flow ratio were 0.84 (Q1-Q3: 0.77-0.90), 0.92 (Q1-Q3: 0.88-0.97), and 0.83 (Q1-Q3: 0.73-0.90), respectively. FFR disagreed with iFR in 16.7% of cases (65 of 390). The median PPGi was 0.75 (Q1-Q3: 0.67-0.85). The physiological pattern of CAD was classified according to the PPGi as predominantly physiologically focal (PPGi ≥0.75) in 209 of 390 vessels (53.6%) or diffuse (PPGi < 0.75) in 181 of 390 vessels (46.4%). The median PPGi was significantly lower in FFR-/iFR+ vs FFR+/iFR- vessels (0.65 [Q1-Q3: 0.60-0.69] vs 0.82 [Q1-Q3: 0.75-0.85]; P < 0.001). Predominantly physiologically focal disease was significantly associated with FFR+/iFR- (76.3% [29 of 38]), while predominantly physiologically diffuse disease was significantly associated with FFR-/iFR+ (96.3% [26 of 27] [P < 0.001] for pattern of CAD between FFR+/iFR- and FFR-/iFR+ groups).

The physiological pattern of CAD is an important influencing factor in FFR/iFR discordance. (Radiographic Imaging Validation and Evaluation for Angio iFR [REVEAL iFR]; NCT03857503).

Vascular steal refers to the diversion of blood flow between collateral vessels that share a common inflow restricted by arterial stenosis. Blood is diverted from the high-pressure to the low-pressure, low-resistance system. Vascular steal is associated with anatomical bypass or vasodilation in the collateral network and is called "the arterial steal". However, we have demonstrated that in the presence of an outflow gradient (e.g., intra-extracranial), blood is shunted to a lower pressure system, a phenomenon we term "venous steal". Using Thevenin's equivalent, we generalized the concept of venous steal to apply it to any region of the vascular system with increased outflow pressure. Both arterial steal, caused by increased collateral network conductivity, and venous steal, resulting from lower collateral outflow pressure, reduce compartment perfusion. This occurs indirectly by increasing flow and the pressure gradient across the arterial stenosis, lowering the segmental compartment perfusion pressure-the difference between post-stenotic (inflow) and compartmental (outflow) pressures. Venous steal diverts blood flow from compartments with elevated pressure, such as intracranial, subendocardial, the ischemic core, and regions of focal edema due to inflammation, trauma, or external compression. In shock and low-flow states, it contributes to regional blood flow maldistribution. Treatment of venous steal addresses inflow stenosis, increased compartmental pressure and systemic loading conditions (arterial and venous pressure) to reverse venous steal malperfusion in the ischemic regions.

Fractional flow reserve is the most widely used physiologic index to establish the functional significance of epicardial coronary artery disease (CAD). Fractional flow reserve guides clinical decisions toward or against coronary revascularization based on a single binary decision threshold indicative of myocardial ischemia. CAD pathophysiological patterns can be evaluated by assessing the distribution of pressure losses along the coronary vessel, often displayed as a "pullback curve." Until recently, the information provided by the pullback curves was visually and subjectively interpreted, which is associated with interobserver variability. The pullback pressure gradient is a novel index that addresses this gap by assessing the longitudinal distribution of the CAD, quantifying it on a scale from 0 to 1, with higher values indicative of predominantly focal CAD and lower values of predominantly diffuse CAD. This review provides a comprehensive analysis and critical appraisal of pullback pressure gradient and future directions.

The homogeneity of coronary microcirculatory dysfunction (CMD) across different myocardial territories in angina with non-obstructive coronary artery disease (ANOCA) patients is scarcely explored. This study investigates the variability in microvascular resistance reserve (MRR) across the 3 main perfusion territories of the coronary circulation to investigate the homogeneity or dishomogeneity of microcirculatory function.

This post-hoc analysis of the PACIFIC trials included symptomatic ANOCA patients with [15O]H2O positron emission tomography (PET) and three-vessel invasive fractional flow reserve (FFR). MRR was computed in the three main coronary branches by integrating PET-derived coronary flow reserve and invasive FFR. A total of 155 patients (50% male, age 59 ± 10 years) and 465 vessels (MRR: 3.92 ± 1.21) were included. There were no significant differences in MRR among the three coronary branches. Correlations in MRR among the three coronary branches were good (r = 0.76 to 0.86). The mean difference between MRR measurements in different arteries was small (2.4 to 7.5%), without any consistent directional bias. The overall intraclass correlation coefficient for absolute agreement was 0.80 (95% CI: 0.74-0.85), indicating good single-measure reliability. Approximately 80% (123/155) of patients showed diagnostic concordance of CMD (MRR ≤3.0) across the three vessels.

In most ANOCA patients, microvascular function is homogeneously distributed across the three major coronary territories. Single-artery testing may suffice in many cases, aligning with guidelines. However, some patients exhibit notable inter-territorial variation, suggesting that multivessel evaluation may be prudent in borderline scenarios.

Coronary heart disease (CHD) is one of the leading causes of mortality worldwide. It is primarily caused by myocardial ischemia and hypoxia resulting from atherosclerotic plaques in the coronary arteries, leading to symptoms such as angina. The severity of CHD determines the treatment approach, which may include medication or interventional therapy. Therefore, accurately assessing the severity of myocardial ischemia is crucial for effective CHD management. In recent years, fractional flow reserve (FFR), derived from the relationship between flow and pressure, has gained widespread recognition for providing valuable information to guide coronary revascularization. Pressure guidewires equipped with pressure sensors at their tips are the most commonly used tools for clinical FFR assessment. These wires measure vessel pressure to determine the severity of coronary lesions. However, during their use, issues such as signal drift, tip breakage, core wire fractures, and coating detachment may occur. This article reviews the historical development of pressure guidewires, examines the general structure of two commonly used pressure guidewires available in the market, highlights typical issues encountered during clinical use, and proposes corresponding solutions.

Peripheral arterial disease (PAD) affects over 236 million people globally, with endovascular treatment as the predominant mode of revascularization. While pre-procedural lesion assessment typically relies on non-invasive Doppler measurement, invasive physiological assessment offers a promising approach to guide lesion selection and provide real-time evaluation of angioplasty success. This review explores the current methods, challenges, and future directions of invasive physiological assessment in PAD. Sensor-tipped wires, particularly pressure sensor-tipped wires (pressure-wires), enable precise evaluation of stenoses through indices such as peripheral fractional flow reserve (pFFR) measured during hyperaemia. pFFR can identify significant flow-limiting lesions, assess angioplasty efficacy, and predict tissue healing. Additional indices, including Doppler-wire derived flow reserves and resistance measurements, further enhance the understanding of lesion physiology. Early data support the utility of these techniques for guiding treatment decisions, although the variability in methodologies highlights the need for standardization and outcome-driven cut-off values. This review uniquely consolidates evidence on invasive physiological assessment in PAD, addressing critical gaps and providing a framework for future research. By advancing lesion-specific evaluation and procedural optimization, this work underscores the transformative potential of these techniques in improving patient outcomes and redefining PAD management.

An increasing number of procedures over the past two decades for aortic stenosis (AS) reflects the combination of an aging population and less invasive transcatheter options. As a result, the hemodynamics of the aortic valve (AV) have gained renewed interest to understand its behavior and to optimize patient selection. We studied the hemodynamic relationship between pressure loss (ΔP) and transvalvular flow (Q) of the normal AV as well as the impact of a variable supravalvular stenosis. Our mechanistic study included 11 healthy swine monitored during dobutamine stress and followed by acute aortic banding to simulate AS. Hemodynamics were continuously recorded, and transvalvular ΔP versus Q were analyzed using proportional and linear models. During dobutamine infusion, normal valves exhibited a highly linear relationship between ΔP and Q (median R2 of 0.93). Progressive aortic banding eventually displayed a highly linear relationship between an increasing ΔP and the decreasing Q, characterized by a constant systemic circulatory resistance (median R2 of 0.91). Consequently, a normal AV can be described by a single parameter: its resistance, median 0.37 Wood units (WU) in swine. During dobutamine stress and aortic banding, the systemic bed behaves like a constant and stable resistance, median of 11.9 WU in swine. These findings carry significant implications for quantifying normal and diseased AV behavior and potentially might improve patient selection and treatment outcomes.NEW & NOTEWORTHY This study demonstrates that the normal aortic valve functions like a resistor with a proportional pressure loss ΔP versus transvalvular flow Q relationship. During dobutamine stress and progressive aortic banding, a "load line" of constant resistance characterizes the systemic circulation. Consequently, during stress conditions, the relative pressure loss over a stenotic aortic valve (the stress aortic valve index, SAVI) quantifies the relative reduction in maximal flow. Potentially, SAVI might optimize patient selection for procedures to treat aortic stenosis.

Previous studies suggest that it may be inappropriate to determine treatment strategies solely based on the degree of stenosis for patients with intracranial atherosclerotic stenosis (ICAS). In order to better risk stratify patients with ICAS, we developed a novel non-invasive fractional flow (FF) calculation technique based on intracranial angiography (Angio-FF) to assess the hemodynamics for patients with ICAS. This study aims to investigate the difference in FF between symptomatic and asymptomatic patients with ICAS and its potential optimal threshold.

A total of 124 patients with ICAS with severe intracranial stenosis who had undergone cerebral angiography were recruited. According to the time of onset, the patients were divided into a symptomatic ICAS group (n=78) and an asymptomatic ICAS group (n=46). The Angio-FF of each group was collected and compared. Receiver-operating characteristic curve (ROC) analysis was performed to assess the discriminative ability of Angio-FF to predict hemodynamics for ICAS.

Compared with the asymptomatic ICAS group, the symptomatic ICAS group had a significantly lower Angio-FF (0.75 (0.66-0.85) vs 0.85 (0.77-0.89), P<0.001). The optimal cut-off value of Angio-FF for distinguishing symptomatic ICAS from asymptomatic ICAS was 0.785 (sensitivity 71.74%, specificity 57.69%).

Patients with Angio-FF <0.7853 may be more prone to intracranial ischemic events. Angio-FF of 0.7853 can serve as a boundary for whether patients with ICAS exhibit clinical symptoms.

The differences between the use of fractional flow reserve (FFR) or instantaneous wave-free ratio (iFR) in the long term are unknown.

To compare long-term outcomes of iFR- and FFR-based strategies to guide revascularization.

The DEFINE-FLAIR multicenter study randomized patients with coronary artery disease to use either iFR or FFR as a pressure index to guide revascularization. Patients from 5 continents with coronary artery disease and angiographically intermediate severity stenoses who underwent hemodynamic interrogation with pressure wires were included. These data were analyzed from March, 13, 2014, through April, 27, 2021.

Five-year major adverse cardiac events (MACE) (a composite of all-cause death, nonfatal myocardial infarction, and unplanned revascularization), as well as the individual components of the combined end point.

At 5 years of follow-up, no significant differences were found between the iFR (mean age [SD], 65.5 [10.8] years; 962 male [77.5%]) and FFR (mean age [SD], 65.2 [10.6] years; 929 male [74.3%]) groups in terms of MACE (21.1% vs 18.4%, respectively; hazard ratio [HR], 1.18; 95% CI, 0.99-1.42; P = .06). While all-cause death was higher among patients randomized to iFR, it was not driven by myocardial infarction (6.3% vs 6.2% in the FFR study arm; HR, 1.01; 95% CI, 0.74-1.38; P = .94) or unplanned revascularization (11.9% vs 12.2% in the FFR group; HR, 0.98; 95% CI, 0.78-1.23; P = .87). Furthermore, patients in whom revascularization was deferred on the basis of iFR or FFR had similar MACE in both study arms (17.9% in the iFR group vs 17.5% in the FFR group; HR, 1.03; 95% CI, 0.79-1.35; P = .80) with similar rates of the components of MACE, including all-cause death. On the contrary, in patients who underwent revascularization after physiologic interrogation, the incidence of MACE was higher in the iFR group (24.6%) compared with the FFR group (19.2%) (HR, 1.36; 95% CI, 1.07-1.72; P = .01).

At 5-year follow up, an iFR based-strategy was not statistically different than an FFR strategy to guide revascularization in terms of MACE, nonfatal myocardial infarction, and unplanned revascularization.

ClinicalTrials.gov Identifier: NCT02053038.

Studies have shown that high-risk plaque features (including thin fibrous caps, lipid-rich cores, large plaque volumes, and intraplaque microcalcifications) are closely associated with the occurrence of acute coronary events. CT-derived fractional flow reserve (CT-FFR) is a non-invasive imaging post-processing technique that utilizes artificial intelligence to analyze data obtained from conventional coronary CT angiography (CCTA). FFR-CT technology offers the hemodynamic assessment of coronary lesions, aiding in the prediction of potential cardiovascular risks. This review summarizes the latest research progress on the complex relationship between FFR-CT, plaque characteristics, and hemodynamics, closely linking plaque volume, composition, and distribution with the clinical significance of coronary artery stenosis. It is hoped that these research findings will provide valuable guidance for clinicians, promoting the application of CT in the non-invasive detection of vulnerable plaques, thereby more effectively preventing and managing coronary artery disease. In the future, further optimization of FFR-CT technology and expansion of its clinical application are expected to significantly reduce the incidence and mortality of coronary artery disease, offering new hope for the prevention and treatment of cardiovascular diseases.

Coronary circulation plays an essential role in delivering oxygen and metabolic substrates to satisfy the considerable energy demand of the heart. This article reviews the history that led to the current understanding of coronary physiology, beginning with William Harvey's revolutionary discovery of systemic blood circulation in the 17th century, and extending through the 20th century when the major mechanisms regulating coronary blood flow (CBF) were elucidated: extravascular compressive forces, metabolic control, pressure-flow autoregulation, and neural pathways. Pivotal research studies providing evidence for each of these mechanisms are described, along with their clinical correlates. The authors describe the major role played by researchers in the 19th century, who formulated basic principles of hemodynamics, such as Poiseuille's law, which provided the conceptual foundation for experimental studies of CBF regulation. Targeted research studies in coronary physiology began in earnest around the turn of the 20th century. Despite reliance on crude experimental techniques, the pioneers in coronary physiology made groundbreaking discoveries upon which our current knowledge is predicated. Further advances in coronary physiology were facilitated by technological developments, including methods to measure phasic CBF and its regional distribution, and by biochemical discoveries, including endothelial vasoactive molecules and adrenergic receptor subtypes. The authors recognize the invaluable contribution made by basic scientists toward the understanding of CBF regulation, and the enormous impact that this fundamental information has had on improving clinical diagnosis, decision-making, and patient care.

The introduction of wire-free microcirculatory resistance index from functional angiography (angio-IMR) promises swift detection of coronary microvascular dysfunction, however it has not been properly validated. We sought to validate angio-IMR against invasive IMR and PET derived microvascular resistance (MVR). Moreover, we studied if angio-IMR could aid in the detection of ischemia with non-obstructive coronary arteries (INOCA). In this investigator-initiated study symptomatic patients underwent [15O]H2O positron emission tomography (PET) and invasive angiography with 3-vessel fractional flow reserve (FFR). Invasive IMR was measured in 40 patients. Angio-IMR and QFR were computed retrospectively. MVR was defined as the ratio of mean distal coronary pressure to PET derived coronary flow. PET and QFR/angio-IMR analyses were performed by blinded core labs. The right coronary artery was excluded. A total of 211 patients (mean age 61 ± 9, 148 (70%) male) with 312 vessels with successful angio-IMR analyses were included. Angio-IMR correlated moderately with invasive IMR (r = 0.48, p < 0.01), whereas no correlation was found between angio-IMR and MVR (r=-0.07, p = 0.25). Angio-IMR did not differ for vessels without obstructive coronary artery disease (CAD) (FFR-) but with reduced stress perfusion (PET+) compared to vessels without obstructive CAD (FFR-) with normal stress perfusion (PET-) (median 28.19 IQR 20.42-38.99 vs. 31.67 IQR 23.47-40.63, p = 0.40). Angio-IMR correlated moderately with invasively measured IMR, whereas angio-IMR did not correlate with PET derived MVR. Moreover, angio-IMR did not reliably identify patients with INOCA.

Cerebrovascular disease is the leading causes of death and disability worldwide. Intracranial atherosclerotic stenosis (ICAS) is one of the major causes of ischemic stroke, especially in the Asian population. It is urgent to explore effective screening methods for early diagnosis to improve prognosis of patients with ICAS. Recently, the concept of panvascular medicine has provided a direction for the exploration of evaluation of ICAS. Based on the concept of "panvascular medicine," atherosclerosis is the common pathological feature of panvascular disease, such as ICAS and coronary artery disease (CAD). In-depth research on the formation and development of plaques, the development and application of more precise preoperative assessment and detection methods, and the utilization of new interventional equipment have greatly enhanced the precision of diagnosis and treatment of CAD. Studies attempt to apply similar evaluation and treatment in ICAS. The deeper understanding, the more accurate diagnosis and treatment, contributing to improve the prognosis of patients with ICAS. This review focuses on these evaluations and treatment of CAD applied in the field of ICAS.

This study investigated the clinical value of coronary arteriography (CAG) combined with fractional flow reserve (FFR) in the treatment of coronary heart disease (CHD) with coronary artery stenosis exceeding 70%. A retrospective analysis was conducted on 344 patients with CHD treated at the Gansu Institute of Cardiovascular Science from January 2020 to May 2022. The patients were divided into the CAG group (n = 138) and the CAG + FFR group (n = 206). Among these patients, those with coronary artery stenosis exceeding 70% underwent an FFR functional examination to accurately determine indicators for coronary intervention. The data collected included demographic information, number of stents, number of vascular lesions, treatment methods, and the occurrence of major adverse cardiovascular events (MACE) at the 6-month follow-up. No significant differences were found between the 2 groups in terms of age, gender, underlying diseases, body mass index (BMI), smoking history, and blood lipid profile. The rate of surgical treatment in the CAG group and the CAG + FFR group was 88.41% and 43.69%, respectively. The CAG + FFR group showed a 44.72% reduction in the need for surgical treatment and a reduced number of stents placed, which helped prevent overtreatment. Additionally, there was no statistical difference between the 2 groups in MACE such as angina pectoris, myocardial infarction, and sudden cardiac death at the 6-month follow-up. After combined CAG examination with FFR measurement, the number of CHD patients with coronary artery stenosis exceeding 70% requiring surgical intervention decreased by 44.72%. FFR could significantly prevent overtreatment and provide more precise guidance for CHD treatments.

Atherosclerosis (AS) is a major cause of cardiovascular disease. In particular, the unpredictable rupture of vulnerable atherosclerotic plaques (VASPs) can cause serious cardiovascular events such as myocardial infarction, stroke, and even sudden death. Therefore, early evaluation of the vulnerability of atherosclerotic plaques is of great importance. However, clinical imaging techniques are only marginally useful in the presence of severe anatomical structural changes, making it difficult to evaluate plaque vulnerability at an early stage. With the development of molecular imaging and nanotechnology, specific nanoprobes constructed for the pathological features of VASPs have attracted much attention for their ability to visualize VASPs early and noninvasively at the cellular and molecular levels. Here, we outline the pathological features of VASPs, analyze the superiority and limitations of current clinical imaging techniques, introduce the rational design principles of nanoprobes, and systematically summarize the application of nanoprobes to visualize the features of VASPs at the cellular and molecular levels. In addition, we discussed the prospects and urgent challenges in this field, and we believe it will provide new ideas for the early and accurate diagnosis of cardiovascular diseases.

Fractional flow reserve (FFR) has emerged as the invasive gold standard for assessing vessel-specific ischemia. However, FFR measurements are influenced by the hydrostatic effect, which might adversely impact the assessment of ischemia.

This study aimed to investigate the impact of hydrostatic pressure on FFR measurements by correcting for the height and comparing FFR with [15O]H2O positron emission tomography (PET)-derived relative flow reserve (RFR).

The 206 patients were included in this analysis. Patients underwent coronary computed tomography angiography (CCTA), [15O]H2O PET, and invasive coronary angiography with routine FFR in every epicardial artery. Height differences between the aortic guiding catheter and distal pressure sensor were quantified on CCTA images. An FFR ≤ 0.80 was considered significant.

The study found a reclassification in 7% of the coronary arteries. Notably, 11% of left anterior descending (LAD) arteries were reclassified from hemodynamically significant to nonsignificant. Conversely, 6% of left circumflex (Cx) arteries were reclassified from nonsignificant to significant. After correcting for the hydrostatic pressure effect, the correlation between FFR and PET-derived RFR increased significantly from r = 0.720 to r = 0.786 (p = 0.009). The average magnitude of correction was +0.05 FFR units in the LAD, -0.03 in the Cx, and -0.02 in the right coronary artery.

Hydrostatic pressure has a small but clinically relevant influence on FFR measurements obtained with a pressure wire. Correcting for this hydrostatic error significantly enhances the correlation between FFR and PET-derived RFR.

The current study aimed to evaluate the causal association between hemodynamically significant stenosis and the occurrence of ischemic myocardium using an experimental animal model of coronary artery stenosis.

In Yorkshire swine (n=10), coronary stenosis in the left anterior descending artery was induced using a customized vascular occluder to create varying degrees of occlusion severity (40%-99%). Serial changes in coronary pressure and flow velocity were measured in the left anterior descending artery before and after the implantation of the vascular occluder. At 1 month, 13N-ammonia positron emission tomography (PET) was performed, followed by the collection of isolated hearts for 2,3,5-Triphenyltetrazolium chloride (TTC) staining to quantify the percent area of necrotic myocardium. Three animals in the control group were evaluated using the same protocols, but without the implantation of a vascular occluder.

The median diameter stenosis after vascular occluder implantation was 61.3% (Q1-Q3: 55.9%-72.3%). Significant differences were observed in hyperemic stenosis resistance, fractional flow reserve (FFR), stress perfusion defect and reversibility in PET, as well as in necrotic myocardium in TTC staining based on stenosis severity (control group: <50%, 50%-70%, 70%-90%, and >90%) (all P<.010). Animals with FFR <0.75 at 1 month exhibited a significantly higher area of stress perfusion defect (30.7±3.1% vs 6.0±4.2%, P<.001), reversibility in PET (11.0±4.0% vs 0.0±0.0%, P=.006), and necrotic myocardium in TTC staining (15.8±6.4% vs 0.0±0.0%, P<.001) than those with FFR ≥ 0.75.

In a porcine model, the induction of hemodynamically significant stenosis with FFR <0.75 was associated with the development of stress perfusion defects and reversibility in PET, as well as necrotic myocardium identified by pathology.

Fractional flow reserve (FFR) measurements are recommended for assessing hemodynamic coronary stenosis severity. Intracoronary ECG (icECG) is easily obtainable and highly sensitive in detecting myocardial ischemia due to its close vicinity to the myocardium. We hypothesized that the remission time of myocardial ischemia on icECG after a controlled coronary occlusion accurately detects hemodynamically relevant coronary stenosis. This retrospective, observational study included patients with chronic coronary syndrome undergoing hemodynamic coronary stenosis assessment immediately following a strictly 1-min proximal coronary artery balloon occlusion with simultaneous icECG recording. icECG was used for a beat-to-beat analysis of the ST-segment shift during reactive hyperemia immediately following balloon deflation. The time from coronary balloon deflation until the ST-segment shift reached 37% of its maximum level, i.e., icECG ST-segment shift remission time (τ-icECG in seconds), was obtained by an automatic algorithm. τ-icECG was tested against the simultaneously obtained reactive hyperemia FFR at a threshold of 0.80 as a reference parameter. From 120 patients, 139 icECGs (age, 68 ± 10 yr old) were analyzed. Receiver operating characteristic (ROC) analysis of τ-icECG for the detection of hemodynamically relevant coronary stenosis at an FFR of ≤0.80 was performed. The area under the ROC curve was equal to 0.621 (P = 0.0363) at an optimal τ-icECG threshold of 8 s (sensitivity, 61%; specificity, 67%). τ-icECG correlated inversely and linearly with FFR (P = 0.0327). This first proof-of-concept study demonstrates that τ-icECG, a measure of icECG ST segment-shift remission after a 1-min coronary artery balloon occlusion accurately detects hemodynamically relevant coronary artery stenosis according to FFR at a threshold of ≥8 s.NEW & NOTEWORTHY Invasive hemodynamic measurements are recommended by the current cardiology guidelines to guide percutaneous coronary interventions in the setting of chronic coronary syndrome. However, those pressure-derived indices demonstrate several theoretical and practical limitations. Thus, this study demonstrates the accuracy of a novel, pathophysiology-driven approach using intracoronary ECG for the identification of hemodynamically relevant coronary lesions by quantitatively assessing myocardial ischemia remission.

The purpose of the present study was to find the independent predictors of Fractional Flow Reserve (FFR) measured immediately after percutaneous coronary intervention with drug-eluting stent implantation (post-PCI FFR) and investigate if applying vessel-specific post-PCI FFR cut-off values to predict target vessel failure (TVF), a composite of cardiac death (CD), non-fatal myocardial infarction (MI) and target vessel revascularization (TVR), or a composite of CD and MI ameliorated its predictive power.

Consecutive patients with post-PCI FFR measurement at our center between 2009 and 2021 were included in this analysis.

A total of 434 patients with 500 vessels were included. Median pre-PCI FFR was 0.72 with no difference between LAD and non-LAD vessels. Median post-PCI FFR was 0.87. LAD location, male gender, smaller stent diameter, and lower pre-PCI FFR proved to be significant predictors of a lower post-PCI FFR. On a vessel-level, post-PCI FFR, stent length, and diabetes mellitus proved to be significant predictors of TVF and the composite of CD and MI. The best post-PCI FFR cut-off to predict TVF or a composite of CD and MI was 0.83 in the LAD and 0.91 in non-LAD vessels.

LAD location is a predictor of a lower post-PCI FFR. Post-PCI FFR is an independent predictor of TVF as well as of the composite of CD and MI. No uniform target post-PCI FFR value exists; different cut-off values may have to be applied in LAD as opposed to non-LAD vessels.

Fractional Flow Reserve (FFR) is generally considered the gold standard in hemodynamics to assess the impact of a stenosis on the blood flow. The standard procedure to measure involves the displacement of a pressure guide along the circulatory system until it is placed next to the lesion to be analyzed. The main objective of the present study is to analyze the influence of the pressure guide on the invasive FFR measurements and its implications in clinical practice.

We studied the influence of pressure wires on the measurement of Fractional Flow Reserve (FFR) through a combination of Computational Fluid Dynamics (CFD) simulations using 45 clinical patient data with 58 lesions and ideal geometries. The analysis is conducted considering patients that were subjected to a computer tomography and also have direct measurements using a pressure guide. Influence of the stenosis severity, degree of occlusion and blood viscosity has also been studied.

The influence of pressure wires specifically affects severe stenosis with a lumen diameter reduction of 50 % or greater. This type of stenosis leads to reduced hyperemic flow and increased coronary pressure drop. Thus, we identified that the placement of wires during FFR measurements results in partial obstruction of the coronary artery lumen, leading to increased pressure drop and subsequent reduction in blood flow. The severity of low FFR values associated with severe stenosis may be prone to overestimation when compared to stenosis without severe narrowing. These results have practical implications, particularly in the interpretation of lesions falling within the "gray zone" (0,75-0,80).

The pressure wire's presence significantly alters the flow on severe lesions, which has an impact on the FFR calculation. In contrast, the impact of the pressure wire appears to be reduced when the FFR is larger than 0.8. The findings provide critical information for physicians, emphasizing the need for cautious interpretation of FFR values, particularly in severe stenosis. It also offers insights into improving the correlation between FFRct models and invasive measurements by incorporating the influence of pressure wires.

To assess the diagnostic accuracy of dobutamine stress echocardiography (DSE) in symptomatic patients with a low to intermediate pretest probability of obstructive coronary artery disease (CAD) and a positive coronary CT angiography (CCTA).

We prospectively enrolled 104 consecutive patients undergoing coronary angiography for symptoms of stable CAD and a CCTA indicative of obstructive CAD. The diagnostic performance of DSE was evaluated against two intracoronary pressure indices: (a) fractional flow reserve (FFR) with a cut-off of ≤0.80 and (b) instantaneous wave-free ratio (iFR) with a cut-off of ≤0.89, indicating haemodynamically significant stenoses.

Of 102 patients, 46 (45%) had at least one significant lesion as defined by FFR, as did 37 (36%) as defined by iFR. DSE showed positive results in 33% (34/102) of cases. The discriminative power of DSE for detecting significant CAD was moderate, with areas under the curve of 0.63 (p=0.024) compared with FFR and 0.64 (p=0.025) compared with iFR. The accuracy, sensitivity and specificity of DSE were, respectively, 61%, 43%, and 75% against FFR, and 64%, 46% and 74% against iFR. The diagnostic accuracy of DSE did not differ significantly between FFR and iFR as a reference (p=0.549).

In patients with positive CCTA, DSE has a moderate ability to identify haemodynamically significant CAD, with low sensitivity and moderate specificity. When assessed against FFR and iFR criteria, its additive diagnostic value is limited in patients with low to intermediate pretest probability of obstructive CAD.

NCT03045601.

There is no definitive approach for assessing mesenteric ischemia and determining the optimal timing for endovascular intervention in the management of spontaneous isolated dissection of the superior mesenteric artery (SISMAD). A 56-year-old male with acute abdominal pain was diagnosed with SISMAD. After evaluating mesenteric ischemia through mesenteric fractional flow reserve (FFR), FFR was 0.72, and the patient was recommended conservative treatment for SISMAD, which involves fasting, total parenteral nutrition, and anticoagulation. The patient's syndrome was relieved after conservative treatment for 14 days without stent implantation. Over the next 5 years, no recurrence of abdominal pain or worsening of SISMAD was observed in the patient. Assessing the severity of mesenteric ischemia can be done through mesenteric FFR. Upon confirmation of the exclusion of risks related to dilatation or rupture of SISMAD aneurysm, an approach in favor of conservative management for SISMAD may indeed be considered pragmatic when the FFR exceeds 0.72.

Introduction: Mild stenosis [degree of stenosis (DS) < 50%] is commonly labeled as nonobstructive lesion. Some lesions remain stable for several years, while others precipitate acute coronary syndromes (ACS) rapidly. The causes of ACS and the factors leading to diverse clinical outcomes remain unclear. Method: This study aimed to investigate the hemodynamic influence of mild stenosis morphologies in different coronary arteries. The stenoses were modeled with different morphologies based on a healthy individual data. Computational fluid dynamics analysis was used to obtain hemodynamic characteristics, including flow waveforms, fractional flow reserve (FFR), flow streamlines, time-average wall shear stress (TAWSS), and oscillatory shear index (OSI). Results: Numerical simulation indicated significant hemodynamic differences among different DS and locations. In the 20%-30% range, significant large, low-velocity vortexes resulted in low TAWSS (<4 dyne/cm2) around stenoses. In the 30%-50% range, high flow velocity due to lumen area reduction resulted in high TAWSS (>40 dyne/cm2), rapidly expanding the high TAWSS area (averagely increased by 0.46 cm2) in left main artery and left anterior descending artery (LAD), where high OSI areas remained extensive (>0.19 cm2). Discussion: While mild stenosis does not pose any immediate ischemic risk due to a FFR > 0.95, 20%-50% stenosis requires attention and further subdivision based on location is essential. Rapid progression is a danger for lesions with 20%-30% DS near the stenoses and in the proximal LAD, while lesions with 30%-50% DS can cause plaque injury and rupture. These findings support clinical practice in early assessment, monitoring, and preventive treatment.

Microvascular Resistance Reserve (MRR) has recently been introduced as a microvasculature-specific index and hypothesized to be independent of coronary stenosis. The aim of this study was to investigate the change of MRR after percutaneous coronary intervention (PCI).

In this post-hoc analysis from the PACIFC trials, symptomatic patients underwent [15O]H2O positron emission tomography (PET) and invasive fractional flow reserve (FFR) before and after revascularization. Coronary flow reserve (CFR) from PET and invasive FFR were used to calculate MRR.

Among 52 patients (87 % male, age 59.4 ± 9.4 years), 61 vessels with a median FFR of 0.71 (95 % confidence interval: 0.55 to 0.74) and a mean MRR of 3.80 ± 1.23 were included. Following PCI, FFR, hyperemic myocardial blood flow (hMBF) and CFR increased significantly (all p-values ≤0.001). MRR remained unchanged after PCI (3.80 ± 1.23 before PCI versus 3.60 ± 0.97 after PCI; p=0.23). In vessels with a pre-PCI, FFR ≤0.70 pre- and post-PCI MRR were 3.90 ± 1.30 and 3.73 ± 1.14 (p=0.56), respectively. Similar findings were observed for vessels with a FFR between 0.71 and 0.80 (pre-PCI MRR 3.70 ± 1.17 vs. post PCI MRR 3.48 ± 0.76, p=0.19).

Our study indicates that MRR, assessed using a hybrid approach of PET and invasive FFR, is independent of the severity of epicardial stenosis. These findings suggest that MRR is a microvasculature-specific parameter.

Computer simulations of coronary fractional flow reserve (FFR) based on coronary imaging have emerged as an attractive alternative to invasive measurements. However, most methods are proprietary and employ non-physiological assumptions. Our aims were to develop and validate a physiologically realistic open-source simulation model for coronary flow, and to use this model to predict FFR based on intracoronary optical coherence tomography (OCT) data in individual patients. We included patients undergoing elective coronary angiography with angiographic borderline coronary stenosis. Invasive measurements of coronary hyperemic pressure and absolute flow and OCT imaging were performed. A computer model of coronary flow incorporating pulsatile flow and the effect of left ventricular contraction was developed and calibrated, and patient-specific flow simulation was performed. Forty-eight coronary arteries from 41 patients were included in the analysis. Average FFR was 0.79 ± 0.14, and 50% had FFR ≤ 0.80. Correlation between simulated and measured FFR was high (r = 0.83, p < 0.001). Average difference between simulated FFR and observed FFR in individual patients was - 0.009 ± 0.076. Overall diagnostic accuracy for simulated FFR ≤ 0.80 in predicting observed FFR ≤ 0.80 was 0.88 (0.75-0.95) with sensitivity 0.79 (0.58-0.93) and specificity 0.96 (0.79-1.00). The positive predictive value was 0.95 (0.75-1.00) and the negative predictive value was 0.82 (0.63-0.94). In conclusion, realistic simulations of whole-cycle coronary flow can be produced based on intracoronary OCT data with a new, computationally simple simulation model. Simulated FFR had moderate numerical agreement with observed FFR and a good diagnostic accuracy for predicting hemodynamic significance of coronary stenoses.

Coronary artery lesions (CALs) after Kawasaki disease present complex coronary hemodynamics. We investigated the relationship between coronary fractional flow reserve (FFR), myocardial flow reserve (MFR), and myocardial blood flow volume fraction (MBF) and their clinical usefulness in CALs after Kawasaki disease. Nineteen patients (18 men, 1 woman) who underwent cardiac catheterization and 13N-ammonia positron emission tomography, with 24 coronary artery branches, were included. Five branches had inconsistent FFR and MFR values, two had normal FFR but abnormal MFR, and three had abnormal FFR and normal MFR. The abnormal MFR group had significantly higher MBF at rest than the normal group (0.86 ± 0.13 vs. 1.08 ± 0.09, p = 0.001). The abnormal FFR group had significantly lower MBF at adenosine loading than the normal group (2.23 ± 0.23 vs. 1.88 ± 0.29, p = 0.021). The three branches with abnormal FFR only had stenotic lesions, but the MFR may have been normal because blood was supplied by collateral vessels. Combining FFR, MFR, and MBF will enable a more accurate assessment of peripheral coronary circulation and stenotic lesions in CALs and help determine treatment strategy and timing of intervention.

Fluid-filled pressure guidewires are unaffected by the previously inevitable hydrostatic pressure gradient (HPG). This study aimed to compare simultaneous pressure measurements with fluid-filled and sensor-tipped pressure guidewires.

Fifty patients underwent fractional flow reserve (FFR) and Pd/Pa measurement with a fluid-filled and a sensor-tipped pressure guidewire simultaneously. To assess maneuverability, patients were randomized with respect to which pressure guidewire was used to cross the lesion first. Lateral fluoroscopy was used to estimate height difference between catheter tip and distal wire position (and thus HPG). Agreement between pressure measurements was studied.

Measurements were performed in LM (4% (n = 2)), LAD (44% (n = 22)), LCX (26% (n = 13)), and RCA (26% (n = 13)). Simultaneous pressure measurements showed excellent agreement (mean FFR difference - 0.01 ± 0.03 (r = 0.959, p < 0.001), mean Pd/Pa difference - 0.01 ± 0.04 (r = 0.929, p < 0.001)). FFR was ≤0.80 in 42.6% (n = 20) with fluid-filled FFR measurements versus 46.8% (n = 22) by sensor-tipped FFR measurements. Mean height difference was 15 ± 34 mm, and strongly dependent on the coronary artery (LAD 45 ± 10 mm, LCX -23 ± 16 mm, RCA -13 ± 17 mm). There was a strong correlation between height difference and difference in pressure ratios between sensor-tipped and fluid-filled pressure guidewires (FFR r = -0.850, p < 0.001; Pd/Par = -0.641, p < 0.001). Largest FFR differences were present in the LAD (-0.04 ± 0.02). After HPG correction, mean difference between HPG-corrected sensor-tipped FFR and fluid-filled FFR was 0.00 ± 0.02, mean Pd/Pa difference was 0.01 ± 0.03.

This study shows excellent overall correlation between FFR and Pd/Pa measurements with both pressure guidewires. Differences measured with fluid-filled and sensor-tipped pressure guidewires are vessel-specific and attributable to hydrostatic pressure gradients (NCT04802681).

Objective: To present a novel pipeline for rapid and precise computation of fractional flow reserve from an analysis of routine two-dimensional coronary angiograms based on fluid mechanics equations (FFR2D). Material and methods: This was a pilot analytical study that was designed to assess the diagnostic performance of FFR2D versus the gold standard of FFR (threshold ≤ 0.80) measured with a pressure wire for the physiological assessment of intermediate coronary artery stenoses. In a single academic center, consecutive patients referred for diagnostic coronary angiography and potential revascularization between 1 September 2020 and 1 September 2022 were screened for eligibility. Routine two-dimensional angiograms at optimal viewing angles with minimal overlap and/or foreshortening were segmented semi-automatically to derive the vascular geometry of intermediate coronary lesions, and nonlinear pressure-flow mathematical relationships were applied to compute FFR2D. Results: Some 88 consecutive patients with a single intermediate coronary artery lesion were analyzed (LAD n = 74, RCA n = 9 and LCX n = 5; percent diameter stenosis of 45.7 ± 11.0%). The computed FFR2D was on average 0.821 ± 0.048 and correlated well with invasive FFR (r = 0.68, p < 0.001). There was very good agreement between FFR2D and invasive-wire FFR with minimal measurement bias (mean difference: 0.000 ± 0.048). The overall accuracy of FFR2D for diagnosing a critical epicardial artery stenosis was 90.9% (80 cases classified correctly out of 88 in total). FFR2D identified 24 true positives, 56 true negatives, 4 false positives, and 4 false negatives and predicted FFR ≤ 0.80 with a sensitivity of 85.7%, specificity of 93.3%, positive likelihood ratio of 13.0, and negative likelihood ratio of 0.15. FFR2D had a significantly better discriminatory capacity (area under the ROC curve: 0.95 [95% CI: 0.91-0.99]) compared to 50%DS on 2D-QCA (area under the ROC curve: 0.70 [95% CI: 0.59-0.82]; p = 0.0001) in predicting wire FFR ≤ 0.80. The median time of image analysis was 2 min and the median time of computation of the FFR2D results was 0.1 s. Conclusion: FFR2D may rapidly derive a precise image-based metric of fractional flow reserve with high diagnostic accuracy based on a single two-dimensional coronary angiogram.

We examined the effect of minimal lumen segmentation uncertainty on Fractional Flow Reserve obtained from Coronary Computed Tomography AngiographyFFR CT . A total of 14 patient-specific coronary models with different stenosis locations and degrees of severity were enrolled in this study. The optimal segmented coronary lumens were disturbed using intra± 6 % and inter-operator± 15 % variations on the segmentation threshold.FFR CT was evaluated in each case by 3D-OD CFD simulations. The findings suggest that the sensitivity ofFFR CT to this type of uncertainty increases distally and with the stenosis severity. Cases with moderate or severe distal coronary lesions should undergo either exact and thorough segmentation operations or invasive FFR measurements, particularly if theFFR CT is close to the cutoff (0.80). Therefore, we conclude that it is crucial to consider the lesion's location and degree of severity when evaluatingFFR CT results.

This review article focuses on the role of adenosine in coronary artery disease (CAD) diagnosis and treatment. Adenosine, an endogenous purine nucleoside, plays crucial roles in cardiovascular physiology and pathology. Its release and effects, mediated by specific receptors, influence vasomotor function, blood pressure regulation, heart rate, and platelet activity. Adenosine therapeutic effects include treatment of the no-reflow phenomenon and paroxysmal supraventricular tachycardia. The production of adenosine involves complex cellular pathways, with extracellular and intracellular synthesis mechanisms. Adenosine's rapid metabolism underscores its short half-life and physiological turnover. Furthermore, adenosine's involvement in side effects of antiplatelet therapy, particularly ticagrelor and cangrelor, highlights its clinical significance. Moreover, adenosine serves as a valuable tool in CAD diagnosis, aiding stress testing modalities and guiding intracoronary physiological assessments. Its use in assessing epicardial stenosis and microvascular dysfunction is pivotal for treatment decisions. Overall, understanding adenosine's mechanisms and clinical implications is essential for optimizing CAD management strategies, encompassing both therapeutic interventions and diagnostic approaches.

Fractional flow reserve is widely used in coronary disease management, with a threshold of 0.80. However, similar thresholds are unclear in functional assessment of intracranial atherosclerotic stenosis (ICAS).

To investigate the potential threshold values in functional assessment of ICAS by studying the relation between pressure-derived indexes and perfusion parameters derived from arterial spin labeling (ASL).

Patients were consecutively screened between June 2019 and December 2020. The translesional gradient indices were measured by pressure guidewire under resting-state conditions and recorded as mean distal/proximal pressure ratios (Pd/Pa) and translesional pressure difference (Pa-Pd). Preoperative and postoperative cerebral blood flow (CBF) bilaterally and the relative cerebral blood flow ratio (rCBF) were measured and recorded by ASL imaging. Patients were defined as having reversible hemodynamic insufficiency only if the preoperative rCBF was <0.9 and the postoperative rCBF≥0.9. Preoperative and postoperative Pd/Pa or Pa-Pd values of those patients were used to calculate the threshold.

Twenty-five patients (19 men, 6 women) with a mean age of 56.7±9.4 years were analyzed. Seventeen patients (68%) had lesions at the M1 segment of the middle cerebral artery, eight patients (32%) had lesions in the intracranial internal carotid artery. In 14 of the 25 patients, the preoperative rCBF was <0.9 and the postoperative rCBF≥0.9. Cut-off values of Pd/Pa=0.81 and Pa-Pd=8 mm Hg were suggested to be associated with hemodynamic insufficiency.

In a highly selected subgroup with ICAS, cut-off values of translesional pressure gradients (Pd/Pa=0.81 or Pa-Pd=8 mm Hg) were preliminarily established, which may facilitate clinical decision-making in the management of ICAS.

The coronary artery constitutes a vital vascular system that sustains cardiac function, with its primary role being the conveyance of indispensable nutrients to the myocardial tissue. When coronary artery disease occurs, it will affect the blood supply of the heart and induce myocardial ischemia. Therefore, it is of great significance to numerically simulate the coronary artery and evaluate its blood supply capacity. In this article, the coronary artery lumped parameter model was derived based on the relationship between circuit system parameters and cardiovascular system parameters, and the blood supply capacity of the coronary artery in healthy and stenosis states was studied. The aortic root pressure calculated by the aortic valve fluid-structure interaction (AV FSI) simulator was employed as the inlet boundary condition. To emulate the physiological phenomenon of sudden pressure drops resulting from an abrupt reduction in blood vessel radius, a head loss model was connected at the coronary artery's entrance. For each coronary artery outlet, the symmetric structured tree model was appended to simulate the terminal impedance of the missing downstream coronary arteries. The particle swarm optimization (PSO) algorithm was used to optimize the blood flow viscous resistance, blood flow inertia, and vascular compliance of the coronary artery model. In the stenosis states, the relative flow and fractional flow reserve (FFR) calculated by numerical simulation corresponded to the published literature data. It was anticipated that the proposed model can be readily adapted for clinical application, serving as a valuable reference for diagnosing and treating patients.

The application of fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) in multivessel coronary artery disease (CAD) patients has not been definitively explored. We herein assessed how treatment strategies were decided based on FFR/iFR values in vessels selected clinically. Specifically, we sought to determine whether treatment selection was based on whether the vessel tested was the clinical target stenosis.

270 consecutive patients with angiographically determined multivessel disease who underwent FFR/iFR testing were included. Patients were classified initially based on their angiographic findings, then re-evaluated from FFR/iFR results (normal or abnormal). Tested lesions were classified into target or non-target lesions based on clinical and non-invasive evaluations.

Abnormal FFR/iFR values were demonstrated in 51.9 % of patients, in whom 51.4 % received coronary stenting (PCI) and 44.3 % had bypass surgery (CABG). With two-vessel CAD patients, medical therapy was preferred when the target lesion was normal (72.6 %), while PCI was preferred when it was abnormal (78.4 %). In non-target lesions, PCI was preferred regardless of FFR/iFR results (78.0 %). With three-vessel CAD patients, CABG was preferred when the target lesion was abnormal (68.5 %), and there was no difference in the selected modality when it was normal. Furthermore, the incidence of tested lesions was higher in the left anterior descending (LAD) compared to other coronary arteries, and two-vessel CAD patients with LAD stenoses were more frequently treated by PCI.

The use of invasive physiologic testing in multivessel CAD patients may alter the preferred treatment strategy, leading to an overall increase in PCI selection.