Clin Res Cardiol (2023).

Aortic Pulsatility Index (API) as a novel hemodynamic index for evaluation of outcome in patients undergoing transcatheter mitral valve repair
P. Dierks1, K. Diehl1, A. Ben Ammar1, U. Hanses1, A. Fach1, I. Eitel2, C. Frerker2, H. Wienbergen1, R. Hambrecht1, R. Osteresch1
1Bremer Institut für Herz- und Kreislaufforschung (BIHKF), Bremen; 2Medizinische Klinik II / Kardiologie, Angiologie, Intensivmedizin, Universitätsklinikum Schleswig-Holstein, Lübeck;

Background: Several studies identified clinical and echocardiographic predictors of worse clinical outcome despite successful transcatheter mitral valve repair (M-TEER). The capability of invasively measured aortic pulsatility index (API) to predict mortality after successful M-TEER is unclear.

Objective: To assess the impact of API on mortality in patients (pts.) with chronic heart failure (CHF) and severe mitral regurgitation (MR) undergoing M-TEER.

Methods: Consecutive pts. with CHF (left ventricular systolic ejection fraction ≤ 50% from any cause) and severe MR who underwent successful M-TEER (MR ≤2+ at discharge) were included and followed prospectively. Primary endpoint was defined as all-cause mortality during a median follow-up period of 17±12 months. API was calculated as: (systolic blood pressure – diastolic blood pressure) / pulmonary capillary wedge pressure. Receiver operator characteristic (ROC) analysis was used to determine discriminative capacity of API. Kaplan-Meier estimate was used for survival analysis. A multivariable Cox proportional-hazards regression analysis was performed to identify independent risk factors for all-cause mortality.

Results: 217 pts. (median age 75±8 years, 63% male) at high operative risk (LogEuro-SCORE 18.5±15%) were enrolled. Mean API was 1.76±1.3. At long-term follow-up 86 pts. died (39.6%). ROC curve analysis demonstrated that API was associated with an area under the curve of 0.62 (95% confidence interval (CI) 0.53-0.7; p=0.005). An API threshold of 1.76 was associated with 62.3% sensitivity and 41.5% specificity for all-cause mortality. At long-term follow-up, a significantly lower survival rate was observed in pts. with API ≤1.76 (33% vs. 47%; log-rank p=0.01). A cox regression analysis supported the assumption of API (Hazard ratio 0.59; 95% CI 0.39 -0.89; p=0.012) as an independent predictor for all-cause mortality besides NYHA class IV and NT-proBNP levels.
Conclusions: API is strongly associated with mortality among pts. with CHF undergoing successful M-TEER. An API cut-off value of 1.76 predicts mortality independent of other important clinical and echocardiographic factors.