Echocardiographic and clinical features of patients developing prosthesis-patient mismatch after TAVR: insights from the Recovery TAVR registry

Background: The impact of prosthesis-patient mismatch (PPM) on major endpoints after transcatheter aortic valve replacement (TAVR) is controversial and the effects on progression of heart damage are poorly investigated. Therefore, our study aims to evaluate the prevalence and predictors of PPM in a "real world" cohort of patients at intermediate and low surgical risk, its impact on mortality and the clinical-echocardiographic progression of heart damage. Methods: 963 patients who underwent TAVR procedure between 2017 and 2021, from the RECOVERY-TAVR international multicenter observational registry, were included in this analysis. Multiparametric echocardiographic data of these patients were analyzed at 1-year follow-up (FU). Clinical and echocardiographic features were stratified by presence of PPM and PPM severity, as per the most current international recommendations, using VARC-3 criteria. Results: 18% of patients developed post-TAVR. PPM, and 7.7% of the whole cohort had severe PPM. At baseline, 50.3% of patients with PPM were male (vs 46.2% in the cohort without PPM, p=0.33), aged 82 (IQR 79-85y) years vs 82 (IQR 78-86 p=0.46), and 55.6% had Balloon-Expandable valves implanted (vs 46.8% of patients without PPM, p=0.04); they had smaller left ventricular outflow tract (LVOT) diameter (20 mm, IQR 19-21 vs 20 mm, IQR 20-22, p=0.02), reduced SVi (34.2 vs 38 ml/m2, p<0.01) and transaortic flow rate (190.6 vs 211 ml/s, p<0.01). At pre-discharge FU patients with PPM had more paravalvular aortic regurgitation (moderate-severe AR 15.8% vs 9.2%, p<0.01). At 1-year FU, maladaptive alterations of left ventricular parameters were found in patients with PPM, with a significant increase in end-systolic diameter (33 mm vs 28 mm, p=0.03) and a significant increase in left ventricle end systolic indexed volume in those with moderate and severe PPM (52 IQR 42-64 and 52, IQR 41-64 vs.44 IQR 35-59 in those without, p=0.02)). No evidence of a significant impact of PPM on overall (p=0.71) and CV (p=0.70) mortality was observed. Patients with moderate/severe PPM had worse NYHA functional class at 1 year (NYHA III-IV 13% vs 7.8%, p=0.03). Prosthesis size≤23 mm (OR 11.6, 1.68-80.1) was an independent predictor of PPM, while SVi (OR 0.87, 0.83-0.91, p<0.001) and LVOT diameter (OR 0.79, 0.65-0.95, p=0.01) had protective effect. Conclusions: PPM was observed in 18% of patients undergoing TAVR. Echocardiographic evaluations demonstrated a PPM-related pattern of early ventricular maladaptive alterations, possibly precursor to a reduction in cardiac function, associated with a significant deterioration in NYHA class at 1 year. These findings emphasize the importance of prevention of PPM of any grade in patients undergoing TAVR procedure, especially in populations at risk.