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

Abstract

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.

Keywords: afterload; aortic valve stenosis; mitral regurgitation.