P1786Impact of surgery for mitral regurgitation at the time of aortic valve replacement

Abstract

Abstract Background Functional mitral regurgitation (MR) is expected to improve after aortic valve replacement (AVR) in patients with severe aortic stenosis (sAS) and MR. However, little is unknown about the impact of AVR on organic MR and whether concomitant mitral valve surgery (MVS) improves outcomes in patients with sAS and MR. Purpose We assessed the impact of AVR on MR severity according to MR mechanism. We also assessed the clinical outcomes in patients with sAS and MR that underwent AVR with vs without MVS. Methods We retrospectively investigated patients who received surgical AVR or transcatheter aortic valve implantation (TAVI) from 2008 to 2017. We identified patients with effective mitral regurgitant orifice area (ERO) ≥10 mm2 by the proximal isovelocity surface area method with transthoracic echocardiography. The change in MR after AVR was considered significant when there was at least one grade difference. We compared the all-cause mortality of patients with sAS and MR that underwent AVR with vs without MVS according to MR mechanism and patient age. Results We included 326 patients with sAS and MR (age 80 [Interquartile range 72–85] years, 53% male, 21% history of myocardial infarction). Organic and functional MR were present in 69% and 31%, respectively. Of these, 240 underwent AVR alone (AVR group) including TAVI in 112 while 86 underwent AVR and MVS (MVS group) including mitral valve replacement in 38 and mitral valve repair in 48. The median ERO at baseline was 17 (14–21) mm2 in AVR and 24 (19–33) mm2 in MVS (p<0.001). Improvement in MR was observed in 58% of AVR and 91% of MVS (p<0.001). In AVR group, organic MR improved as frequently as functional MR (58% vs. 59%, p=0.96). Predictors for improvement in organic MR were absence of atrial fibrillation and moderate or greater MR, and in functional MR, the only predictor was decrease in LV end-systolic diameter after AVR. During mean follow-up of 2.4±2.3 years, moderate or greater MR was observed in 23% of AVR and 7% of MVS (p=0.002). All-cause mortality was similar in AVR and MVS groups for organic and functional MR (hazard ratio for MVS group 0.68, 95% CI: 0.40–1.10, p=0.13 in organic MR and 0.62, 95% CI 0.29–1.22, p=0.68 in functional MR). All-cause mortality was lower in MVS group compared with AVR group in patients <80 years, and was similar in patients ≥80 years (Figure). Conclusion In patients with sAS and MR, MR improves after AVR, even in the majority of patients with organic MR. Compared with isolated AVR, concomitant MVS was associated with better prognosis in patients <80 years.