Echo-derived pulmonary arterial systolic pressure (PASP) and right ventricular (RV) tricuspid annular plane systolic excursion (TAPSE; from the end of diastole to end-systole) are of basic relevance in the clinical follow-up of heart failure (HF) patients, carrying two- to threefold increase in cardiac risk when increased and reduced, respectively. We hypothesized that the relationship between TAPSE (longitudinal RV fiber shortening) and PASP (force generated by the RV) provides an index of in vivo RV length-force relationship, with their ratio better disclosing prognosis. Two hundred ninety-three HF patients with reduced (HFrEF, n = 247) or with preserved left ventricular (LV) ejection fraction (HFpEF, n = 46) underwent echo-Doppler studies and N-terminal pro-brain-type natriuretic peptide assessment and were tracked for adverse events. The median follow-up duration was 20.8 mo. TAPSE vs. PASP relationship showed a downward regression line shift in nonsurvivors who were more frequently presenting with higher PASP and lower TAPSE. HFrEF and HFpEF patients exhibited a similar distribution along the regression line. Given the TAPSE, PASP, and TAPSE-to-PASP ratio (TAPSE/PASP) collinearity, separate Cox regression and Kaplan-Meier analyses were performed: one with TAPSE and PASP as individual measures, and the other combining them in ratio form. Hazard ratios for variables retained in the multivariate regression were as follows: TAPSE/PASP </≥ 0.36 mm/mmHg [hazard ratio (HR): 10.4, P < 0.001]; TAPSE </≥ 16 mm (HR: 5.1, P < 0.01); New York Heart Association functional class </≥ 3 (HR: 4.4, P < 0.001); E/e' (HR: 4.1, P < 0.001). This study shows that the TAPSE vs. PASP relationship is shifted downward in nonsurvivors with a similar distribution in HFrEF and HFpEF, and their ratio improves prognostic resolution. The TAPSE vs. PASP relationship as a possible index of the length-force relationship may be a step forward for a more efficient RV function evaluation and is not affected by the quality of LV dysfunction.
Keywords: pulmonary arterial systolic pressure; right ventricle; survival; tricuspid annular plane systolic excursion.