Percutaneous Aortic Valve Replacement Results in an Acute Reduction in Mitral Regurgitation

Objective: Patients with severe aortic stenosis often have associated functional mitral regurgitation (MR) that is thought to be secondary to increased intraventricular pressure and abnormal mitral valve geometry due to LV dilatation and dysfunction. Following percutaneous transcatheter aortic valve replacement (TAVI) there is an acute reduction in afterload. We sought to examine if this resulted in acute reduction in overall mitral regurgitation, remodelling of the left ventricle and mitral valve geometry. Methods: Forty-seven consecutive patients undergoing TAVI had transthoracic echocardiography performed pre and immediately post (one to two days). An experienced cardiologist graded severity of mitral regurgitation as trivial, mild, moderate and severe. We also measured mitral annulus diameter and the mitral valve tenting area pre and post TAVI. Results: As expected there was a reduction in left ventricular afterload by a significant decrease in both peak and mean gradients (both p < 0.001). There was a significant decrease in mitral regurgitation noted immediately post TAVI (p = 0.0027). Pre procedure 10 patients were graded as having moderate or severe mitral regurgitation. Post procedure only five patients had moderate or severe mitral regurgitation. Between pre and post echocardiographic assessments there was an increase in mitral annulus diameter and tenting area (p = 0.0015 and p = 0.0073 but no significant change in LV dimensions and systolic function. Conclusion: TAVI results in acceptable haemodynamic profiles by echocardiography in the short-term. Post-implantation there was a significant reduction in MR. Our findings indicate that this immediate reduction in MR is the result of afterload reduction and effect on intraventricular pressure rather than changes in mitral valve geometry or ventricular remodelling.