The Impact of Transcatheter Aortic Valve Replacement on Mitral Regurgitation and Pulmonary Hypertension

Background: The presence of concomitant Mitral Regurgitation (MR) and Pulmonary Hypertension (PH) is a common issue in patients undergoing Transcatheter Aortic Valve Replacement (TAVR). Transthoracic echocardiography plays a role in detecting MR severity and PH before and after TAVR.

Objectives: This study aimed to investigate the impact of TAVR on MR severity and PH and to detect the predictors of their improvement.

Methods: Totally, 111 patients underwent TAVR at Rajaee Heart Center, Tehran, Iran from December 2012 to January 2021. In this retrospective study, these patients were evaluated for MR and PH improvement after TAVR. The final analysis was performed separately on 32 patients who had moderate or more severe baseline MR and 56 patients with any grade of PH at baseline. Group comparisons based on the MR severity, PH severity, and improvement of MR and PH were analyzed using student t-test for continuous variables and chi-square or Fisher’s exact test for categorical ones. Finally, the percentage of the patients with improved MR or PH as well as the factors associated with the improvements were determined.

Results: Moderate or more severe baseline MR improved by at least one grade one year post-TAVR in 56.2% of the cases, and TAVR with a balloon-expandable valve was associated with a higher probability of MR improvement. Baseline left ventricular ejection fraction was significantly lower in patients with a higher degree of PH than in those with lower degrees (43% vs. 30%, P < 0.001). In addition, right ventricular dysfunction was more prevalent in patients with a higher degree of PH. Post-TAVR reduction in systolic pulmonary pressure (at least 10 mmHg) was observed in 77% of the patients after one year.

Conclusions: TAVR positively affected MR and PH and reduced their severity in most patients. Tricuspid native aortic valve (in comparison with bicuspid), normal sinus rhythm (in comparison with atrial fibrillation), left ventricular ejection fraction improvement, and absence of left atrial enlargement were associated with a greater MR improvement after TAVR. Left ventricular ejection fraction improvement and TAVR with a balloon-expandable valve were also significantly associated with PH improvement post TAVR.