Prognosis of functional mitral regurgitation after aortic valve replacement for pure severe aortic stenosis

Whether patients with severe aortic stenosis (AS) and significant functional mitral regurgitation (MR) should undergo isolated aortic (aortic valve replacement [AVR]) or double aortic-mitral valve procedure (DVP) remains controversial. We sought to determine outcomes of such patients undergoing surgical (surgical aortic valve replacement [SAVR]) and transcatheter AVR (TAVR) or DVP, identify echocardiographic parameters predictive of significant residual MR after isolated AVR, and determine its impact on long-term survival.

Data prospectively collected from 736 consecutive patients with severe AS and significant MR undergoing AVR or DVP were retrospectively analyzed. Exclusion of organic MR, other valve diseases and concomitant CABG yielded a final population of 74 patients with significant functional MR (32 TAVR, 23 SAVR, 19 DVP). Demographics, postoperative complications and age-adjusted survival were compared. Echocardiographic predictors of significant residual MR and its impact on survival were analyzed for patients undergoing isolated AVR.

In the isolated AVR group, MR improvement occurred in 60% of patients and was associated with a significant increase in survival compared to persistence of significant MR (p = .03). Patients with improved MR had significantly greater preoperative left ventricular dilatation (LVEDD: 49 vs. 43 mm, p = .001; LVESD: 35 vs. 29 mm, p = .03; LVEDV: 101 vs. 71 ml, p = .0003; LVESV: 57 vs. 33 ml, p = .002). There was no significant difference in perioperative mortality (5.3 vs. 4.4 vs. 9.4%, p = .85) or age-adjusted long-term survival between isolated AVR and DVP groups (76.3 vs. 84.2% survival at 2-year follow-up, p = .26), or between SAVR, TAVR and DVP groups (78.2 vs. 75.0 vs. 84.2% survival at 2-year follow-up, p = .13).

After isolated AVR, MR improvement occurs in 60% of patients. It is predicted by greater ventricular dimensions and associated with significantly better long-term survival. Whether a staged approach with transcatheter correction of MR should be considered in patients with significant residual MR following AVR remains undetermined.