Is the Improvement in Mitral Regurgitation Post TAVR an Acute Phenomenon?

Abstract

Background: Mitral regurgitation (MR) is common in patients worked up for TAVR. Unfortunately, its presence portends poorer clinical outcomes and the question arises if these patients are best served by surgery to address both pathologies. Previous studies have shown MR improvement when assessed several months post TAVR. This study is unique as its objective was to assess changes in MR and possible mechanisms within the first 48 hours, with a view to develop a predictive model to determine which patients would improve. Methods: This study consisted of 132 patients with aortic stenosis who underwent TAVR, with echocardiographic assessment prior and post TAVR. The echocardiographic parameters related to MR severity including mitral valve geometry, left ventricular size and function were assessed for significant correlation with MR improvement. Results: 88 of the 132 patients had more than mild MR. In this cohort 52 patients (60%) had an improvement in MR of at least 1 grade immediately post TAVI. Subgroup analysis showed no significant change in mitral valve geometry after TAVI [tenting height (0.76 ± 0.20 vs 0.74 ± 0.17, p = 0.78) tenting area (2.14 ± 0.63 vs 2.00 ± 0.69, p = 0.26, coaptation depth (0.47 ± 0.12 vs 0.55 ± 0.18, p = 0.07]. Left ventricular volumes (44.19 ± 19.56 vs 45.6 ± 22.35, p = 0.94)] and LVEF (55.23 ± 9.93 vs 54 ± 9.98, p = 0.60) did not change significantly after TAVR. Conclusions: A significant proportion of patients have a decrease in MR immediately (within 48 hours) post TAVR. This improvement relates to a reduction in afterload and hence the driving intraventricular pressure rather than immediate changes in LV dynamics or mitral valve geometry.