Echocardiographic and clinical features of patients developing prosthesis-patient mismatch after TAVI: insights from an international multicenter registry

Abstract Background The impact of prosthesis-patient mismatch (PPM) after transcatheter aortic valve implantation (TAVI) is controversial. Purpose Our study aims to evaluate the impact of PPM on mortality and clinical-echocardiographic progression of cardiac damage in a "real world" cohort of patients at intermediate and low surgical risk and to characterize its main predictors. Methods 963 patients who underwent TAVI procedure between 2017 and 2021, from an international multicenter observational registry, were included in this analysis. Multiparametric echocardiographic data 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 (VARC-3 criteria). Results 18% of patients developed post-TAVI PPM, (7.7% of the whole cohort severe). At baseline, 50.3% of patients with PPM were male (vs 46.2% in the cohort without PPM, p=0.33), aged 82y (interquartile range (IQR) 79-85y) vs 82y (IQR 78-86y; 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 (20mm, IQR 19-21 vs 20mm, IQR 20-22, p=0.02), reduced Stroke Volume index (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 (AR) (moderate/severe AR 15.8% vs 9.2%, p<0.01). At a median FU of 1.46 years (IQR 1-4), there was no evidence of a significant impact of PPM on overall mortality (15.3% vs 13.1%, p=0.46) nor on rehospitalization rate for heart failure (4.3% vs 8.0%, p=0.10). At 1-year FU, maladaptive alterations of left ventricular parameters were found in patients with PPM, with a significant increase in endsystolic diameter (ESD) (33 vs 28mm, p=0.03) and a statistically non-significant increase in LV mass index (121 vs 106g/m2, p=0.07). Interestingly, trajectory parameters of patients with PPM from baseline to 1-year FU showed a reduced cardiac remodeling compared to patients without PPM, including no LVEF improvement (p=0.88), absent reduction of LV end-diastolic volume (p=0.70), indexed LV mass (p=0.31), ESD (p=0.48) and pulmonary artery systolic pressure (p=0.82), and an increase of basal RV diameter (p<0.001). Patients with moderate/severe PPM had worse NYHA functional class at 1 year (NYHA III-IV 13% vs 7.8%, p=0.03). Independent predictor of PPM at multivariable logistic regression was male gender (OR=1.93, p=0.04); while SVi (OR=0.86, p<0.001), prosthetic size >23mm (OR=0.62, p=0.03) and LVOT diameter (OR=0.79, p=0.02) had protective effect. Conclusions There was no evidence of a short- or medium-term impact of PPM on mortality. However, clinical-echocardiographic evaluations demonstrated a PPM-related pattern of early ventricular maladaptive alterations associated with a significant deterioration in NYHA class at 1 year.