Association of Pulmonary Hypertension With Clinical Outcomes of Transcatheter Mitral Valve Repair

Question What is the association of pulmonary hypertension with clinical outcomes in patients undergoing transcatheter mitral valve repair? Findings In this cohort study of 4071 patients in the Society of Thoracic Surgery/American College of Cardiology Transcatheter Valve Therapy registry, pulmonary hypertension was common and associated with increased mortality and readmissions for heart failure after transcatheter mitral valve repair for severe mitral regurgitation. However, even in patients with severe pulmonary hypertension, transcatheter mitral valve repair was safe and effective and resulted in improved functional capacity. Meaning These findings emphasize the adverse association of pulmonary hypertension with clinical outcomes after transcatheter mitral valve repair for mitral regurgitation and the need for efforts to determine whether earlier intervention before pulmonary hypertension develops will improve clinical outcomes. Importance Pulmonary hypertension (pHTN) is associated with increased risk of mortality after mitral valve surgery for mitral regurgitation. However, its association with clinical outcomes in patients undergoing transcatheter mitral valve repair (TMVr) with a commercially available system (MitraClip) is unknown. Objective To assess the association of pHTN with readmissions for heart failure and 1-year all-cause mortality after TMVr. Design, Setting, and Participants This retrospective cohort study analyzed 4071 patients who underwent TMVr with the MitraClip system from November 4, 2013, through March 31, 2017, across 232 US sites in the Society of Thoracic Surgery/American College of Cardiology Transcatheter Valve Therapy registry. Patients were stratified into the following 4 groups based on invasive mean pulmonary arterial pressure (mPAP): 1103 with no pHTN (mPAP, <25 mm Hg [group 1]); 1399 with mild pHTN (mPAP, 25-34 mm Hg [group 2]); 1011 with moderate pHTN (mPAP, 35-44 mm Hg [group 3]); and 558 with severe pHTN (mPAP, >= 45 mm Hg [group 4]). Data were analyzed from November 4, 2013, through March 31, 2017. Interventions Patients were stratified into groups before TMVr, and clinical outcomes were assessed at 1 year after intervention. Main Outcomes and Measures Primary end point was a composite of 1-year mortality and readmissions for heart failure. Secondary end points were 30-day and 1-year mortality and readmissions for heart failure. Linkage to Centers for Medicare & Medicaid Services administrative claims was performed to assess 1-year outcomes in 2381 patients. Results Among the 4071 patients included in the analysis, the median age was 81 years (interquartile range, 73-86 years); 1885 (46.3%) were women and 2186 (53.7%) were men. The composite rate of 1-year mortality and readmissions for heart failure was 33.6% (95% CI, 31.6%-35.7%), which was higher in those with pHTN (27.8% [95% CI, 24.2%-31.5%] in group 1, 32.4% [95% CI, 29.0%-35.8%] in group 2, 36.0% [95% CI, 31.8%-40.2%] in group 3, and 45.2% [95% CI, 39.1%-51.0%] in group 4; P < .001). Similarly, 1-year mortality (16.3% [95% CI, 13.4%-19.5%] in group 1, 19.8% [95% CI, 17.0%-22.8%] in group 2, 22.4% [95% CI, 18.8%-26.1%] in group 3, and 27.8% [95% CI, 22.6%-33.3%] in group 4; P < .001) increased across pHTN groups. The association of pHTN with mortality persisted despite multivariable adjustment (hazard ratio per 5-mm Hg mPAP increase, 1.05; 95% CI, 1.01-1.09; P = .02). Conclusions and Relevance These findings suggest that pHTN is associated with increased mortality and readmission for heart failure in patients undergoing TMVr using the MitraClip system for severe mitral regurgitation. Further efforts are needed to determine whether earlier intervention before pHTN develops will improve clinical outcomes. This cohort study assesses the association of pulmonary hypertension with clinical outcomes in patients undergoing transcatheter mitral valve repair.