Right Ventricular Contraction Patterns in Patients Undergoing Transcatheter Tricuspid Valve Repair for Severe Tricuspid Regurgitation

OBJECTIVES This study investigated patterns of right ventricular (RV) contraction by using cardiac magnetic resonance (CMR) imaging in patients undergoing transcatheter tricuspid valve repair (TTVR). BACKGROUND The role of RV function in patients with severe tricuspid regurgitation undergoing TTVR is poorly understood. METHODS Global RV dysfunction was defined as CMR-derived RV ejection fraction (RVEF) #45% and longitudinal RV dysfunction was defined as tricuspid annular plane systolic excursion (TAPSE) <17 mm on echocardiography. Patients were stratified into 3 types of RV contraction: type I, TAPSE $17 and RVEF >45%; type II, TAPSE <17 and RVEF >45%; and type III, TAPSE <17 and RVEF #45%. CMR feature tracking was performed to assess longitudinal and circumferential RV strain. The primary outcome was a composite of all-cause mortality or first heart failure hospitalization. RESULTS Of 79 patients (median age 79 years, 51% female), 18 (23%) presented with global and 40 (51%) presented with longitudinal RV dysfunction. The composite outcome occurred in 22 patients (median follow-up 362 days). Global RV dysfunction but not longitudinal RV dysfunction (hazard ratio: 6.62; 95% confidence interval: 2.77-15.77; and hazard ratio: 1.30; 95% confidence interval: 0.55-3.08, respectively) was associated with the composite outcome. Compared with type I RV contraction, patients with type II RV contraction exhibited increased circumferential strain, with a pres-ervation of RVEF despite diminished longitudinal strain. Patients with type III RV contraction exhibited both diminished longitudinal and circumferential strain, resulting in an impaired RVEF. Patients with type III RV contraction showed the worst survival (P < 0.001). CONCLUSIONS Global RV dysfunction is a predictor of outcomes among TTVR patients. Tricuspid regurgitation patients can be stratified into 3 types of RV contraction, in which a loss of longitudinal function can be compensated by increasing circumferential function, preserving RVEF and favorable outcomes. (J Am Coll Cardiol Intv 2021;14:1551-61) (c) 2021 by the American College of Cardiology Foundation.