Significant reduction in mitral regurgitation volume is the main contributor for increase in systolic forward flow in patients with functional mitral regurgitation after transcatheter aortic valve replacement: Hemodynamic analysis using echocardiography

Background Reduction in mitral regurgitation (MR) after transcatheter aortic valve replacement (TAVR) has previously been reported. However, the hemodynamic effects of TAVR in patients with MR have not been previously evaluated. Methods We analyzed 571 patients who underwent TAVR from December 2010 to December 2013. We studied 20 patients with moderate or severe preprocedural functional mitral regurgitation (FMR) who also had a follow-up transthoracic echocardiography (TTE) examination between 90 and 360 days (median 213 days) after TAVR (Significant FMR Group). We also studied age- and gender-matched 20 patients with mild or lesser MR (Nonsignificant MR Group). Left ventricular functional measurements were assessed using echocardiography before and after TAVR. Left ventricular outflow tract stroke volume measurements using pulsed-wave Doppler (SV_LVOT) were calculated as a representative of systolic forward flow, and stroke volume by the Simpson's method (SV_Simpson) was calculated as a parameter of degree of LV contraction. Results MR grade improved in 22 of 40 patients after TAVR. In both groups, BNP level decreased, left ventricular ejection fraction increased, and SV_LVOT increased after TAVR. SV_Simpson increased in the Nonsignificant MR Group and remained unchanged in the Significant FMR Group. Vena contracta width of MR (MRVC) decreased in the Significant FMR Group. Using multivariable analysis in the Significant FMR Group, the increase in SV_LVOT significantly correlated with the decrease in MRVC (P < 0.05). Conclusions SV_LVOT increased significantly after TAVR in patients with FMR. In these patients, increase in SV_LVOT after TAVR was associated with decrease in severity of MR.