Acute bi-ventricular haemodynamic changes after transcatheter aortic valve implantation for severe aortic stenosis assessed using invasive pressure-volume loops

Transcatheter aortic valve implantation (TAVI) aims to relieve the increased left ventricular (LV) afterload imposed by aortic stenosis (AS). However, the early haemodynamic impact of TAVI on bi-ventricular performance remains poorly characterised. This prospective study quantified the acute bi-ventricular response following TAVI for severe symptomatic AS using gold-standard invasive pressure-volume loop (PVL) assessment. Left and right ventricular (RV) PVLs were recorded using a conductance catheter pre- and immediately post-TAVI. Indices of contractile function, ventriculo-arterial coupling and energetics were derived. In total, 12 patients (84.1 years [interquartile range: 77.1, 87.2]; female 25%) were included. TAVI resulted in significant bi-ventricular reductions in afterload, measured by effective arterial elastance (LV: 2.1 [1.8, 2.3] to 1.4 [1.3, 1.7] mmHg/mL, p < 0.001; RV: 0.5 [0.4, 0.6] to 0.4 [0.3, 0.4] mmHg/mL, p = 0.006). Despite an acute decline in LV contractility, measured by end-systolic elastance (p = 0.021), there was a significant net improvement in ventriculo-arterial coupling in both the LV (p = 0.003) and RV (p = 0.006). Both the LV and RV demonstrated significant reductions in stroke work (SW) (LV-SW: 11,915.0 [9,727.5, 15,288.7] to 7,360.5 [6,937.0, 9,113.1] mmHg/mL, p < 0.001; RV-SW: 1,506.9 [1,420.5, 1,676.2] to 1,418.1 [1,250.8, 1,510.3] mmHg/mL, p = 0.020) and pressure volume area (PVA) (LV-PVA: 16,188.5 [13,171.5, 18,726.5] to 9,674.2 [9,185.9, 11,872.2] mmHg/mL, p < 0.001; RV-PVA 2,176.1 [2,046.3, 2,885.1] to 1,960.2 [1,835.6, 2,269.0] mmHg/mL, p = 0.002), with stable SW/PVA ratios. The acute haemodynamic effects of TAVI for severe symptomatic AS extend beyond the LV. Patients experienced bi-ventricular unloading, improved ventriculo-arterial coupling and reduced myocardial metabolic demand.