Cardiac Remodeling and Outcomes of Patients With Combined Aortic and Mitral Regurgitation

Abstract

Background: Management of patients with combined aortic and mitral regurgitation (AR and MR) is largely based on expert opinion. Specifically, the outcomes of patients with combined moderate AR and moderate MR under medical surveillance are uncertain. Objectives: This study aimed to evaluate cardiac remodeling using cardiac magnetic resonance (CMR) in patients with combined AR/MR compared with isolated AR, to assess degree of MR associated with adverse outcomes, and evaluate the outcomes of asymptomatic patients with combined moderate AR and moderate MR under medical surveillance. Methods: The authors conducted a multicenter observational outcome study of patients with moderate or severe AR on CMR, and evaluated the etiology and degree of concomitant MR in patients with combined AR and MR. They excluded patients if they had prior valvular surgery, > mild valve stenosis, hypertrophic or infiltrative cardiomyopathy, or congenital heart disease except bicuspid aortic valve. The authors evaluated ventricular volumes and function across the spectrum of regurgitation severity. Receiver-operating characteristic analyses for the association of concomitant MR severity with outcomes were performed. The primary outcome was all-cause death. Secondary outcome was all-cause death or heart failure (HF) hospitalization. Patients were censored at the time of valvular surgery or intervention. Propensity score matching was done between isolated AR and the combined AR/MR groups. Results: The authors studied 915 patients with a median age of 61 years (Q1-Q3: 49-72 years), 79.5% male, 29% with bicuspid aortic valve, and a median AR fraction of 38% (Q1-Q3: 32%-45%). In 251 of 915 patients (27.4%) with concomitant MR, the median MR fraction was 24% (Q1-Q3: 17%-35%). The presence of concomitant ≥moderate MR (14.2% of the total population) was associated with a greater increase in ventricular volumes per unit increase in AR severity, and a decline in ventricular function (P for interaction ≤0.01). During a median follow-up of 3.0 years (Q1-Q3: 1.1-5.6 years), there were 152 deaths. Presence of concomitant ≥moderate MR was associated with an increased hazard for all-cause death (HR: 2.77; 95% CI: 1.91-4.01; P < 0.001), and the secondary outcome of death or HF (HR: 2.62; 95% CI: 1.87-3.67; P < 0.001). In asymptomatic or minimally symptomatic patients undergoing medical surveillance, the presence of combined moderate AR and moderate MR was independently associated with a higher hazard for the primary and secondary outcomes compared with isolated AR, independent of age, sex, comorbidities, ejection fraction, and end-systolic volume. Findings were consistent in the propensity matched cohort. Conclusions: The presence of combined AR and MR on CMR is associated with a greater extent of ventricular remodeling and increased hazard for adverse outcomes, compared with isolated AR. Asymptomatic patients with combined moderate AR and MR under medical surveillance are at higher risk for death and HF, and warrant further study.