BACKGROUND: Whether patients with severe aortic stenosis (AS) and significant (≥moderate) functional mitral regurgitation (FMR) should undergo isolated aortic valve replacement (AVR) or double aortic and mitral valve replacement (DVR) remains controversial. Accordingly, we sought to compare their perioperative and long-term outcomes following AVR or DVR. Among patients undergoing isolated AVR, we also sought to determine the impact of significant residual MR on long-term survival.
METHODS AND RESULTS: Data prospectively collected from 736 consecutive patients with severe AS and FMR were retrospectively analyzed, and their echocardiograms reviewed by a single blinded cardiologist. Patients with organic or ischemic MR (previous or concomitant CABG/PCI), previous AVR or more-than-mild aortic regurgitation were excluded, resulting in 74 patients constituting our study population. Of these, 19 patients had a DVR, and 55 patients an isolated AVR. Among patients undergoing DVR, 14 (74%) underwent mitral valve replacement and 5 (26%) underwent mitral valve repair. Their pre-operative characteristics, post-operative complications and age-adjusted survival over time were compared. Patients from the isolated AVR group were older and had milder FMR (87% moderate and 13% severe MR vs 12% moderate and 88% severe MR in the DVR group, p < 0.0001). Patients undergoing DVR required more post-operative blood transfusions (84% vs 38%, p=0.0005) and had a longer hospital stay (9.9 vs 7.0 days, p=0.01), but there were no differences in perioperative mortality (5.3% vs 6.7%, p=0.83) or other complications compared with patients undergoing isolated AVR. After adjustment for age, there was no significant difference in survival over time between the two groups (p=0.26, see figure). However, patients in the isolated AVR group whose MR improved following surgery (60%) had significantly increased long-term survival compared with patients in the group with significant residual MR (40%) (p=0.03).
CONCLUSION: In patients with severe AS and significant FMR, DVR is not associated with significant differences in perioperative mortality, perioperative complications and long-term age-adjusted survival. In patients undergoing isolated AVR, nearly a third remain with significant residual MR at long-term follow up, and persistence of significant residual MR after surgery is associated with significantly lower long-term survival. This suggests that in patients with significant FMR and severe AS, a concomitant mitral intervention should be strongly considered, or a staged approach contemplated in the absence of MR improvement after the initial surgery.