Impact of mitral regurgitation in patients with acute heart failure: insights from the RELAX-AHF-2 trial

Aims: The impact of mitral regurgitation (MR) in patients hospitalized for acute heart failure (AHF) is not well established. We assessed the role of MR in patients enrolled in the Relaxin in Acute Heart Failure 2 (RELAX-AHF-2) trial. Methods and results: Patients enrolled in RELAX-AHF-2 with available data regarding MR status were included in this analysis. Baseline characteristics, in-hospital data, and clinical outcomes through 180-day follow-up were evaluated. The impact of moderate/severe MR was assessed. Among 6420 AHF patients with known MR status, 1810 patients (28.2%) had moderate/severe MR. Compared to patients with no/mild MR, those with moderate/severe MR were more likely to have history of heart failure (HF), prior HF hospitalization, more comorbidities, symptoms/signs of HF, lower left ventricular ejection fraction and higher N-terminal pro-B-type natriuretic peptide levels. Moderate/severe MR was associated with longer length of hospital stay, higher rates of residual dyspnoea, increased jugular venous pressure through the index hospitalization and a higher unadjusted risk of the composite of cardiovascular (CV) death or rehospitalization for HF/renal failure (RF) through 180 days (crude hazard ratio [HR] 1.15, 95% confidence interval [CI] 1.03–1.27, p = 0.01). The association between moderate/severe MR and poorer outcomes was not maintained in a multivariable model including several covariates of interest (adjusted HR 1.03, 95% CI 0.91–1.17, p = 0.65). Similar findings were observed for HF/RF rehospitalization alone. Conclusions: In patients with AHF, moderate/severe MR was associated with a worse clinical profile but did not have an independent prognostic impact on clinical outcomes. © 2023 The Authors. European Journal of Heart Failure published by John Wiley & Sons Ltd on behalf of European Society of Cardiology