UPSTREAM EFFECTS OF TRANSCATHETER MITRAL VALVE REPAIR : IMPACT ON TRICUSPID VALVE REGURGITATION

Abstract

Trans-catheter mitral valve repair (TMVr) with MitraClip (Abbott, Menlo Park, CA) has become the standard of care for patients with severe symptomatic mitral regurgitation (MR) who are inoperable or considered ‘high risk’ for conventional surgery. Up to 50% of patients who are candidates for TMVr also have concomitant functional tricuspid regurgitation (TR), posing a challenge to clinicians with little data to guide management. While the hypothesis that reduction in MR leads to lower right ventricular afterload and an improvement in TR has face validity, whether this actually occurs remains unknown. As such, our objective was to determine whether patients with MR who undergo TMVr experience a concomitant reduction in TR. A retrospective observational cohort study was performed at Sunnybrook Health Sciences Centre (Toronto, Canada) including patients who underwent TMVr between April 2011 and February 2018. All patients who had a follow-up echocardiogram available after successful TMVr were included. A detailed chart abstraction was performed including clinical characteristics, echocardiographic parameters and procedural characteristics. The primary outcome was change in TR after TMVr (comparing baseline to 3 month follow-up). Paired t-tests and Wilcoxon signed rank test were used to determine statistical significance. The final study cohort included 197 patients. The median age was 79 years (interquartile range, (IQR) 72-84); 36.4% were females (see Table). Most patients were NYHA class III and IV and the mean STS score was 7.4%-5.9% (standard deviation, SD). The mitral valve pathology was functional in 51.8%, degenerative in 40.6% and mixed in 7.6%. A mean of 1.9-0.6 (SD) clips were used per patient. At follow-up, moderate or less MR was present in 185 patients (93.9%; p < 0.001 as compared to baseline) and the mean gradient was 4 mmHg (median; IQR 3 – 6). There was a significant reduction in right ventricular systolic pressure (RVSP, 49-16 (SD) mmHg at baseline vs 43-17 (SD) mmHg post-TMVr; p < 0.001). A significant overall reduction in TR was observed (see Figure). 82 patients (41.6%) experienced a reduction; 70 patients (40.1%) had no change; and, 36 patients (18.3%) had worsening of TR after TMVr. Of the 36 patients who had worsening TR, only 4 had moderate-severe or severe MR. Patients who undergo TMVr experience a significant concomitant improvement in TR perhaps in part mediated by a reduction in RVSP. Future work should seek to identify which patients are most likely to experience this reduction and the associated clinical outcomes.View Large Image Figure ViewerDownload Hi-res image Download (PPT)