THE RELATIONSHIP BETWEEN TRICUSPID ANNULAR SYSTOLIC EXCURSION AND PULMONARY ARTERIAL SYSTOLIC PRESSURE IN HEART FAILURE: AN INDICATOR OF CARDIAC LENGHH VERSUS FORCE RELATIONSHIP THAT DISCLOSES DISEASE SEVERITY AND PROGNOSIS

Background Right ventricular (RV) dysfunction carries a remarkable risk of death in heart failure (HF). Echo-derived pulmonary artery systolic pressure (PASP) and tricuspid annular systolic excursion (TAPSE), as an indicator of RV systolic function, are of remarkable clinical value in the follow-up of HF patients. We hypothesized that the relationship between TAPSE (longitudinal RV fiber shortening) and PASP (developed force) would provide an index of RV force-length relationship and that their ratio would better disclose disease severity and prognosis compared to either variable independently. Methods A cohort of 293 stable HF patients with both reduced (HFrEF, n=247) and preserved left ventricular ejection fraction (HFpEF, n=46) underwent echo-Doppler and tissue Doppler imaging as well as NT-pro-BNP biomarker assessment and prospectively tracked for adverse events. Results TAPSE vs PASP relationship showed a downward shift of the regression line for nonsurvivors that were distributed in the more unfavorable relationship with highest PASP and lower TAPSE. A similar regression line was observed for patients with HFrEF and HFpEF. Given the collinearity between both TAPSE and PASP and the TAPSE/PASP ratio, separate Cox regression and Kaplan-Meier analyses were performed; the first with TAPSE and PASP as individual measures and the second combining them in ratio form. HR for variables retained in the multivariate regression, using the TAPSE/PASP ratio as optimal dichotomous threshold were: TAPSE/PASP <≥ 0.36 (HR: 10.4, p<0.01); NT-pro-BNP