Concomitant Moderate Aortic Stenosis with Moderate Mitral Regurgitation in Patients with Normal Ejection Fraction: Types, Natural History, and Outcomes.

BACKGROUND

Concomitant moderate aortic stenosis (AS) and moderate mitral regurgitation (MR) remain poorly understood despite its increasing prevalence with population aging. We aimed to evaluate characteristics, mechanisms, cardiac remodeling, and clinical outcomes of MR in patients with concomitant moderate AS and moderate MR compared to each moderate and severe AS without concomitant MR.

METHODS

Patients with concordant moderate AS and moderate MR (Moderate AS + MR), concordant moderate AS without moderate MR (Moderate AS - MR), and concordant severe AS without moderate MR (Severe AS - MR) were identified. Patients with moderate/severe aortic regurgitation, moderate/severe mitral stenosis, severe MR, or low ejection fraction were excluded. The primary end point of all-cause mortality under medical management was compared using multivariable analysis and propensity score matching. Cardiac remodeling on follow-up echocardiograms was compared between the groups using annualized changes.

RESULTS

Overall, 277 patients with Moderate AS + MR, 7,446 with Moderate AS - MR, and 2,706 with Severe AS - MR were included. Patients with Moderate AS + MR were the oldest, with the most frequent prevalence of congestive heart failure, atrial fibrillation, pulmonary hypertension, and right ventricular enlargement/dysfunction. Mitral regurgitation was primary in 64% and secondary in 36%. Over a median 1.9 years, patients with Moderate AS + MR experienced excess mortality over time versus Moderate AS - MR (P = .003), and this excess was observed earlier in secondary MR (within 0.5 year) and later in primary MR (at ∼2 years). Patients with Severe AS -MR had higher mortality versus Moderate AS - MR (P < .001) and numerically but not statistically higher mortality versus Moderate AS + MR (P = .13). Patients with Moderate AS + MR had accelerated decline in left ventricular ejection fraction compared to Moderate AS - MR.

CONCLUSION

Concomitant moderate MR in moderate AS is associated with more congestive heart failure and worse pulmonary pressures and outcomes compared to moderate AS without MR. These patients may benefit from closer follow-up; whether these patients benefit from earlier intervention requires investigation.