A minimum threshold activated clotting time (ACT) to guide heparin dosing during percutaneous coronary intervention (PCI) is associated with lower ischemic complications. However, data are variable regarding the risk of high ACT levels. The aim of this study was to assess the impact of peak procedural ACT on complications and mortality for transfemoral and transradial access PCI.

The UC San Diego Health National Cardiovascular Data Registry CathPCI Registry was used to obtain data on patients who underwent native vessel PCI from January 2007 to September 2022. Coronary artery bypass graft patients and those who received bivalirudin were excluded. Complications and all-cause mortality at 30 days and 1-year post-PCI were assessed by ACT tertile.

A total of 2473 patients (age 65 ± 12 years; 74% male) undergoing PCI with 53% femoral and 47% radial access were included. The majority (82%) had 1-vessel coronary artery disease with heterogeneous clinical presentations (21.8% ST-elevation myocardial infarction, 25.4% non-ST-elevation myocardial infarction, 4.9% unstable angina, 33.8% stable angina, 3.4% atypical chest pain, 10.7% other indication for PCI). With femoral access, patients in the third tertile (ACT ≥ 275) had significantly higher all-cause mortality at 30 days (5.3% vs 2.7% vs 0.9%; P < .001), 6 months (6.3% vs 4.0% vs 2.0%; P = .007), and 1 year (9.0% vs 6.0% vs 2.7%; P < .001) compared to the second (ACT 228-275) and first tertile (ACT ≤ 228), respectively. A 30-day landmark analysis revealed that there was no difference in all-cause mortality beyond 30 days (3.9% vs 3.4% vs 1.8%; P = .176). There were increased bleeding complications in the highest tertile (12.8% vs 9.8% vs 7.5%; P = .034) and a higher need for blood products (10.4% vs 6.7% vs 5.4%; P = .014). There was no difference in ischemic major adverse cardiovascular events specifically periprocedural myocardial infarction or stroke between tertiles. There was no difference in clinical outcomes by peak ACT for patients who had radial access.

Higher ACT with transfemoral access PCI was associated with increased 30-day mortality, bleeding complications, and need for blood products post-PCI.

Unfractionated heparin (UFH) is the preferred anticoagulant agent in percutaneous coronary intervention (PCI) procedures for minimising the risk of thrombotic complications. Because of the narrow therapeutic range of UFH, some society guidelines have advocated the use of the activated clotting time (ACT) test to monitor anticoagulation intensity during PCI to reduce thrombotic and bleeding complications. We aimed to assess the current practice of UFH prescription and its monitoring in Australia and New Zealand (ANZ).

We conducted an anonymous voluntary cross-sectional survey of interventional cardiologists (ICs) who were members of the Cardiac Society of Australia and New Zealand in 2022. The survey included 10 questions pertaining to the current practice of anticoagulation during PCI.

Of 430 ICs surveyed, 148 responded (response rate, 34.4%). Most ICs (84.4%) prescribed 70-100 IU/kg of UFH for PCI. Over half of ICs (58.7%) routinely measured ACT during PCI, whereas only 22.2% routinely measured ACT after PCI to guide additional UFH prescription. Among ICs who prescribed additional UFH, approximately half (48%) aimed for ACT ≥250 seconds. Factors that influenced post-PCI UFH prescription included vascular access site and concomitant antiplatelet or anticoagulant therapy.

The contemporary practice of UFH prescription during PCI and ACT monitoring in ANZ is variable and based on outdated evidence preceding current drug-eluting stents, antiplatelet therapies, and radial-first practice. Current society guideline recommendations lack clarity and agreement, reflecting the quality of the available evidence. Up-to-date clinical trials evaluating UFH prescription and ACT monitoring are needed to optimise clinical outcomes in contemporary PCI procedures.

Inappropriately high activated clotting time (ACT) during percutaneous coronary intervention (PCI) is associated with an increased risk of bleeding events. However, whether the prescription of direct oral anticoagulants (DOACs) affects ACT kinetics during heparin use and adverse clinical events in patients who underwent PCI remains unclear. We aimed to evaluate the relations between ACT changes during and adverse clinical events after PCI in patients who were prescribed DOAC. This observational study included 246 patients who underwent PCI at the 2 cardiovascular centers who were not receiving warfarin and whose ACT was recorded immediately before and 30 minutes after injection of unfractionated heparin. Patients were divided into 2 groups according to DOAC prescription at the time of the index PCI: DOAC users (n = 31) and nonusers (n = 215). Any bleeding and systemic thromboembolic events were investigated until 30 days after PCI. The average age of this population was 70.5 years, and 66.3% were male. Average ACT was significantly higher in DOAC users than nonusers both before and 30 minutes after unfractionated heparin induction (157.2 ± 30.1 vs 131.8 ± 25.1 seconds, p <0.001; 371.1 ± 122.2 vs 308.3 ± 82.2 seconds, p <0.001; respectively). The incidence of systemic thromboembolism after PCI was low and comparable between the 2 groups (0% vs 3.7%, p = 0.60). However, the rate of any bleeding event was significantly higher in DOAC users than in nonusers (16.1% vs 4.7%, p = 0.028). Patients receiving DOAC have higher ACT during PCI and higher incidence of bleeding events than those not receiving DOAC.

The activated clotting time (ACT) assay is used to monitor and titrate anticoagulation therapy with unfractionated heparin during percutaneous coronary intervention (PCI). Observations at our institution suggested a considerable difference between ACT values drawn from varying arterial sites, prompting the current study. Patients undergoing PCI with unfractionated heparin therapy were prospectively enrolled. Simultaneous arterial blood samples were drawn from the access sheath and the coronary guide catheter. Differences between Hemochron ACT values were determined, and potential interactions with clinical variables were analyzed. Immediately postprocedure, the simultaneous mean guide and sheath ACTs were 327 ± 62 seconds and 257 ± 44 seconds, respectively, with a mean difference of 70 ± 60 seconds (P < .001). Nearly all (90%) ACT values obtained via the guide catheter were higher than the concurrent ACT drawn from the sheath. Logistic regression analysis demonstrated that lower weight-adjusted heparin doses and absence of diabetes were associated with a greater difference between the ACT values. We conclude that the ACT value is substantially greater when assessed via the guide catheter versus the access sheath. Although the biological mechanisms require further study, this difference should be considered when managing anticoagulation during PCI and when reporting ACT as part of research protocols.