Mechanisms and implications of mitral regurgitation in patients with severe aortic stenosis who received transcatheter aortic valve replacement

INTRODUCTION: This study aimed to investigate the mechanisms and clinical implications of mitral regurgitation (MR) in patients with severe aortic stenosis (AS) who received transcatheter aortic valve replacement (TAVR). METHODS: We conducted retrospective echocardiographic analyses at baseline and 6 months after TAVR in 140 patients with symptomatic AS (85 ± 5 years) who underwent TAVR. We defined significant MR as ≥ moderate based on evaluation of transthoracic echocardiography (TTE). RESULTS: There were 48 patients (34%) with preexisting MR at the baseline. Among measured TTE parameters, end-systolic wall stress (ESWS), mitral annulus area, and mitral valve thickening index were independent factors associated with preexisting MR (odds ratio [OR]: 1.013, 95% confidence interval [CI]: 1.005-1.021; OR: 1.740, 95% CI: 1.314-2.376; OR: 2.306, 95% CI: 1.426-3.848; respectively). Six months after TAVR, there were 34 patients with post-existing MR, A history of atrial fibrillation and ESWS after TAVR were independent factors (OR: 3.013, 95% CI: 1.208-7.556; OR: 1.013, 95% CI: 1.000-1.023; respectively). The Kaplan-Meier plot indicated that preexisting MR was a risk factor for heart failure-related events within 1 year of discharge after TAVR (p = .012). CONCLUSIONS: In patients who underwent TAVR for severe AS, preexisting MR was associated with having a thickened mitral valve and large mitral annulus size induced by high ESWS. These patients may have worse prognosis after TAVR and should be closely monitored in the long term.