Untreated mild-moderate mitral regurgitation after isolated aortic valve replacement for aortic stenosis

BACKGROUND: Postoperative persistent/worsening mitral regurgitation (MR) is reported to be a prognostic marker in patients undergoing isolated aortic valve replacement (AVR). However, there is little evidence regarding the surgical indication for coexisting mild-to-moderate MR in patients undergoing isolated surgical AVR. This study evaluates the relationship between untreated mild-to-moderate MR and postoperative significant MR after surgical AVR. METHODS: Between 2016 and 2021, 430 patients with severe aortic stenosis underwent isolated surgical AVR with untreated mild-to-moderate MR. The primary endpoint was significant (moderate or greater) MR at 1 year after surgery. Composite endpoint (mortality and heart failure readmission) was also retrospectively reviewed. The mean follow-up duration was 5.0 ± 2.0 years. RESULTS: At 1 year after surgery, 22 patients (5%) presented with moderate or greater MR. Multivariable analysis showed aortic valve peak velocity (OR, 0.44; 95% CI, 0.22-0.89; P= .021), moderate MR (OR, 11.9; 95% CI, 3.80-38.5; P = < 0.001), and left atrial dimension index (OR, 1.12; 95% CI, 1.02-1.25; P= .020) at baseline were risk factors for postoperative significant MR. The freedom from composite endpoint were significantly lower in patients with multiple risk factors for MR than those without (log-rank P= .041). CONCLUSIONS: In patients undergoing isolated surgical AVR with untreated mild-to-moderate MR, preoperative aortic velocity, left atrial dimension, and moderate MR were associated with postoperative significant MR, as well as increased heart failure readmission rates. These risk factors need to be considered in coexisting mild-to-moderate MR when treating aortic valvular lesion. CLINICAL REGISTRATION NUMBER: Approved by the Clinical Research Ethics Committee of Osaka University Hospital: Approval No.: 20,222 (T2).