Prognostic Value of a New Right Ventricular-to-Pulmonary Artery Coupling Parameter Using Right Ventricular Longitudinal Shortening Fraction in Patients Undergoing Transcatheter Aortic Valve Replacement: A Prospective Echocardiography Study

Introduction: Right-ventricular-to-pulmonary artery (RV-PA) coupling, measured as the ratio of tricuspid annular plane systolic excursion (TAPSE) to pulmonary artery systolic pressure (PASP), has emerged as a predictor factor in patients undergoing transcatheter aortic valvular replacement (TAVR). Right ventricular longitudinal shortening fraction (RV-LSF) outperformed TAPSE as a prognostic parameter in several diseases. We aimed to compare the prognostic ability of two RV-PA coupling parameters (TAPSE/PASP and the RV-LSF/PASP ratio) in identifying MACE occurrences. Method: A prospective and single-center study involving 197 patients who underwent TAVR was conducted. MACE (heart failure, myocardial infarction, stroke, and death within six months) constituted the primary outcome. ROC curve analysis determined cutoff values for RV-PA ratios. Multivariable Cox regression analysis explored the association between RV-PA ratios and MACE. Results: Forty-six patients (23%) experienced the primary outcome. No significant difference in ROC curve analysis was found (RV-LSF/PASP with AUC = 0.67, 95%CI = [0.58-0.77] vs. TAPSE/PASP with AUC = 0.62, 95%CI = [0.49-0.69]; p = 0.16). RV-LSF/PASP < 0.30%.mmHg^-1 was independently associated with the primary outcome. The 6-month cumulative risk of MACE was 59% (95%CI = [38-74]) for patients with RV-LSF/PASP < 0.30%.mmHg^-1 and 17% (95%CI = [12-23]) for those with RV-LSF/PASP ≥ 0.30%.mmHg^-1; (p < 0.0001). Conclusions: In a contemporary cohort of patients undergoing TAVR, RV-PA uncoupling defined by an RV-LSF/PASP < 0.30%.mmHg^-1 was associated with MACE at 6 months.