Impact of mitral valve regurgitation severity on clinical outcomes in patients with severe aortic stenosis undergoing TAVI

Abstract

Abstract Background Significant mitral regurgitation (MR) is among the most common cardiac diseases associated with severe aortic stenosis (AS). It is frequently caused or exacerbated by increased left ventricular diastolic pressure and/or diameter, with consequent stretching of the mitral annulus and reduction of leaflet coaptation. Transcatheter aortic valve implantation (TAVI) has been established as an alternative treatment in patients with severe AS, with a prevalence of MR that ranges from 3–37%, but in this setting is typically left untreated. Prognostic clinical impact of concomitant MR in patients undergoing TAVI on outcomes is not clear and conflicting results have been reported. Purpose We sought to investigate the clinical impact of significant MR (≥2+) on mortality at 1-year follow-up in a group of patients with severe aortic stenosis that underwent TAVI procedure. Secondary objective was to evaluate the rate of re-hospitalization during that time. Methods From July 2010 to December 2019 information was gathered from a total 400 patients with severe aortic stenosis who underwent successful TAVI procedure at a University Hospital. We performed a monocentric, non-randomized, observational and prospective study that evaluated clinical outcomes following TAVI in patients with severe aortic stenosis and significant MR (≥2+; Group A) compared to those with mild or absent MR (<2+; Group B). The primary end point was the percentage of all-cause mortality at 1-year follow-up. Secondary end point was the rate of re-hospitalization following TAVI procedure at 1-year follow-up. Results The mean age of the global population (n=400) was 83±7 years and 243 were females (60.7%). Among the total sample, 72 (18%) patients had baseline moderate to severe MR (Group A) and were compared to the remaining 328 patients with mild or absent MR (Group B). At one-year follow-up, we observed a statistically significant higher all-cause mortality in 10 (22.3%) patients from Group A compared to 10 (6.7%) in Group B (p=0.05). The rate of re-hospitalization was significantly higher (p=0.01), occurring in 38.8% (85) of patients in Group A compared to 25.9% (28) in Group B. Conclusion Baseline significant MR (≥2+) in patients with severe aortic stenosis that underwent TAVI was associated with higher all-cause mortality and re-hospitalization at 1-year follow-up. To date, it is not clear whether this association is related to MR severity or if is simply a marker of worst prognosis. Further studies are warranted to reproduce these results. Funding Acknowledgement Type of funding sources: None. Kaplan-Meier estimates of survival