Prognostic impact of aortic pulsatility index on event-free survival in patients with heart failure with preserved ejection fraction

Abstract

Objective: This study sought to determine the predictive value of aortic pulsatility index (API) on event-free survival in patients with heart failure with preserved ejection fraction (HFpEF). Methods: We retrospectively studied 121 patients with HFpEF who underwent right heart catheterization at Heart Failure Center in Fuwai Hospital, Chinese Academy of Medical Sciences, between November 2014 and August 2022. API was calculated as pulse pressure/pulmonary arterial wedge pressure. Patients were divided into three groups according to the tertiles of baseline API. The primary outcome was event-free survival, which was considered as freedom from death, heart transplantation, left ventricular assist device implantation, or HF rehospitalization. We compared the differences in clinical characteristics among the three groups of patients. Spearman correlation analysis was used to calculate the correlation coefficient between API and parameters reflective of left heart function. We used Cox proportional-hazards regression models to estimate hazard ratios (HR) for event-free survival. Receiver operating characteristic curve was used to calculate the area under the curve (AUC) of API for predicting event-free survival in patients with HFpEF. Quantitative data is represented by M (Q1, Q3). Results: The age was 59.0 (46.0, 66.5) years, and 84 (69.4%) patients were male. API and left ventricular stroke work (LVSW) were significantly correlated (r=0.478, P<0.001). The correlation between API and cardiac power output was also significant (r=0.224, P=0.014). Patients with API>3.77 presented with lower serum N-terminal pro-B-type natriuretic peptide (NT-proBNP) values [492(163, 2 776) vs 2 962(722, 5 831) vs 3 823(1 419, 10 262) ng/L], lower left atrial dimension [38(34,42) vs 43(39, 48) vs 45 (42,53) mm], lower right atrial pressure [5 (2, 8) vs 8 (4, 13) vs 13 (8, 16) mmHg(1 mmHg=0.133 kPa)], and lower mean pulmonary arterial pressure [15 (11, 20) vs 22 (17, 26) vs 33 (26, 37) mmHg] (all P<0.05). The median follow-up time of the study was 366.0 (189.8, 648.5) days, and by the end of the follow-up, a total of 51 patients had reached the primary outcome. The cumulative event-free incidence rates of patients in the API>3.77 group, 1.89<API≤3.77 group, and API≤1.89 group were 77.5%, 56.1%, and 40.0%, respectively (P<0.001). After multivariate adjustment, API (HR=0.849,95%CI:0.728-0.989, P=0.035) remained significantly associated with event-free survival. The AUC (95%CI) was 0.700 (0.607-0.793) (P<0.001) for API to predict event-free survival calculated from receiver operating characteristic analysis, with an optimal cut-off value of 3.28, sensitivity of 80.4%, and specificity of 52.9%. Conclusions: API was closely related to parameters reflective of left heart function. Decreased API was an independent predictor of adverse outcomes in patients with HFpEF. API could provide additional prognostic value beyond NT-proBNP.