Pressure–Volume–Derived Ventricular Energetics Across Mechanical Circulatory Support Strategies in Cardiogenic Shock

Bedside pressure-flow variables in cardiogenic shock (CS) incompletely characterize ventricular energetics and coupling. We prospectively derived bedside pressure-volume (PV) loop surrogates from paired pulmonary artery catheter and echocardiographic data in 68 patients (263 paired assessments) with acute myocardial infarction-related CS (AMI-CS) or heart failure-related CS (HF-CS) during microaxial support, intra-aortic balloon pump (IABP) support, or medical therapy. In AMI-CS with microaxial support, arterial elastance decreased (-1.22 mm Hg/ml) with improved coupling (ventriculoarterial coupling [VAC] -1.42), stroke work increased (+140 mm Hg·ml), and pressure-volume area declined (PVA -103 mm Hg·ml), yielding an efficiency rise from ~32% to ~40%, suggesting unloading. In HF-CS, microaxial support reduced elastance modestly (-0.35) with probable efficiency gain (+5%) but heterogeneous PVA changes. In AMI-CS treated with IABP, coupling improved (VAC -0.42) with modest energetic augmentation, whereas HF-CS showed pressure and energy amplification (end-systolic pressure +23.9 mm Hg; PVA +220.6 mm Hg ·ml). Without mechanical support, AMI-CS demonstrated reduced elastance and pressure, while HF-CS exhibited ventricular dilation (end-diastolic volume [EDV]/end-systolic volume ESV increase) with higher energetic demand. Pressure-volume-derived metrics identify device-specific energetic signatures not fully captured by conventional hemodynamic assessment and may provide mechanistic insight into ventricular unloading strategies; validation against conductance catheter-derived PV measurements remains warranted.