Long-term clinical and echocardiographic outcome following TAVR in patients with severe aortic stenosis and different transvalvular flow state

Abstract Aims Haemodynamic classifications of severe aortic stenosis (AS) have important prognostic implications, with low flow state (defined on the basis of a stroke volume index, SVi<35 mL/m2) known to be a predictor of worse prognosis. As transcatheter aortic valve replacement (TAVR) has become widely used for patients with severe AS, issues were raised concerning its efficacy in patients with different haemodynamic classifications combining transvalvular flow state and pressure gradients. In fact, data on TAVR outcomes in patients with low gradient (LG) AS are limited and in some cases controversial. The aim of this study was to evaluate the efficacy and long-term clinical and echocardiographic outcome of TAVR in patients with different transvalvular flow-gradient patterns. Methods In this single centre study, 1078 patients (mean age 81±7 years) with severe symptomatic AS (AVA<1 cm2) undergoing TAVR were categorized according to flow-gradient patterns as follow: 867 patients (80%) with normal flow-high gradient (NF-HG: mean transaortic gradient DP mean>40 mmHg), 94 (9%) with paradoxical low flow LG (pLF-LG: DP mean<40 mmHg, ejection fraction EF > 50%, and SVi<35 mL/m2), and 117 (11%) classical LF-LG (DP mean<40 mmHg, EF < 50%, SVi<35 mL/m2). Results TAVR was feasible in all AS subtypes with similar rate of unsuccessful procedure (1.3% NF-HG, 1.1% pLF-LG, 0% LF-LG P=470). Valvular function after TAVR was excellent over time with respect to aortic pressure gradient (mean and peak) and aortic valve area regardless of flow state group (Figure A). Overall, intraoperative (P=957) and 30-day mortality (P=817) did not differ significantly among the 3 groups. Longer follow-up showed that, compared to NF-HG patients, pLF-LG had similar all-cause mortality rate [HR 1.35(0.95–1.90), P=0.094] up to 5 years and LF-LG had a significant higher mortality rate [HR 1.89(1.43–2.49), P<0.001],(Figure B). Moreover, LF-LG patients had higher rehospitalization for heart failure (NF-HG: 3%, pLF-LG: 6%, LF-LG 10%, P=0.001). Conclusions We provided evidence that TAVR is an effective procedure in all patients with severe AS regardless of transvalvular flow-gradient patterns. A careful haemodynamic classifications of severe AS is of utmost importance for identifying patients who benefits the most from TAVR procedure.