Characterizing the molecular landscape of venous congestion

Table 3 Studies in intensive care unit settings

Ref.	Objective	Disease state	Venous congestion measurement	Proteins investigated	Pathobiology findings
Benkreira et al[56], 2019 (n = 382)	To investigate if portal vein flow pulsatility identifes patients with congestion at risk for delirium	Post-cardiac surgery	US: Portal vein flow pulsatility	NTproBNP	Portal vein pulsatility was associated with cognitive dysfunction, asterixis, and delirium. ↑ NTproBNP levels were associated with cognitive dysfunction
Ishaq et al[24], 2022 (n = 77)	To compare IVC diameter and pro-BNP for IV fluid administration in critically ill patients on intermittent positive pressure ventilation	Congestive heart failure	Echo: IVC diameter	NTproBNP	↑ IVC size associated with NTproBNP in patients with heart failure, and may be beneficial in discriminating between congestion and non-congestion in heart failure
Kitai et al[57], 2017 (n = 69)	To investigate if elevated I-FABP identifies patients with advanced heart failure who have venous and intestinal congestion.	Acute decompensated heart failure	Echo: Routine parameters, TAPSE, RV FAC, E/e’, RHC: PCWP/RAP	FABP2	↑ FABP was associated with worse clinical outcomes (death, transplant or LVAD placement); No association between FABP and right sided filling pressures or with echocardiographic parameters suggesting venous congestion
Pichon et al[35], 2023 (n = 91)	To investigate arterial and venous renal doppler in acute decompensated precapillary pulmonary hypertension	Pulmonary hypertension/acute right heart failure	US: IRVF, RVSI, RRI, Echo: Routine parameters, TAPSE, tv s’, E/A, VTI, RHC: CVP, mPAP, PAWP, RAP, CI	NTproBNP	↑ RRI was associated with age, hypertension, congestion (RAP and renal pulse pressure), cardiac function (TAPSE, VTI), systemic pressure and NTproBNP. ↑ RVSI was associated with congestion (high CVP, RAP, renal pulse pressure), right cardiac function (TAPSE), severe TR and systemic pressures
Zelt et al[36], 2018 (n = 178)	To assess the utility of NTproBNP, NGAL, and hs-cTNT for prediction and detection of congestive AKI	Cardiac surgery/congestive nephropathy	Echo: RV FAC, RHC: CVP, CI, PCWP	hs-cTnT, NTproBNP, NGAL	Baseline and postoperative NTproBNP, postoperative hs-cTnT, and change in hs-cTnT predicted AKI caused by congestion. Congestive AKI was associated with duration of mechanical ventilation and hospital/ICU length of stay

US: Ultrasound; Echo: Echocardiography; IVC: Inferior vena cava; I-FABP: Intestinal fatty acid-binding protein; TAPSE: Transannular plane of systolic excursion; RV FAC: Right ventricular fractional area of change; RHC: Right heart catheterization; PAWP/PCWP: Pulmonary capillary wedge pressure; RAP: Right atrial pressure; IRVF: Intrarenal venous flow; RSVI: Renal venous stasis index; RRI: Renal resistive index; TVs’: Tricuspid valve s’; VTI: Velocity time integral; CVP: Central venous pressure; mPAP: Mean pulmonary arterial pressure; CI: Cardiac index; ICU: Intensive care unit; AKI: Acute kidney injury.