Prognostic significance of right ventricular-pulmonary artery coupling assessed by TAPSE/PASP ratio in patients with HFmrEF.

Right ventricular-pulmonary artery (RV-PA) coupling is an indicator of the degree to which the right ventricle can adapt to afterload. The ratio of tricuspid annular plane systolic excursion (TAPSE) to pulmonary artery systolic pressure (PASP) (TAPSE/PASP ratio) has been proposed as a non-invasive measure of RV-PA coupling. RV-PA coupling is a key prognostic predictor of heart failure (HF); however, HF with mildly reduced left ventricular ejection fraction (HFmrEF) is difficult to predict. This study aimed to determine the prognostic significance of the TAPSE/PASP ratio in HFmrEF. This retrospective cohort study selected eligible patients from two previous cohorts of patients who were hospitalized for HF and discharged with HFmrEF diagnosed by echocardiography: one cohort from August 2015 to September 2019 and one from April 2020 and March 2023. The primary indicator was the TAPSE/PASP ratio, and the primary endpoint was a composite of all-cause mortality and HF rehospitalization. Patients were categorized into two groups based on the median TAPSE/PASP ratio, and the high and low TAPSE/PASP ratio groups were compared. Multivariate analysis was performed using the Cox proportional hazards model. This study included 391 patients (median age, 72 [60-80] years; 70% male). The median TAPSE/PASP ratio used as a cut-off was 0.54 mm/mmHg. The low TAPSE/PASP group was older (median age, 75 [67-82] vs. 68 [56-77] years, p < 0.001), had fewer men (65% vs. 76%, p = 0.019), and had higher B-type natriuretic peptide levels (267 [135-629] vs. 161 [54-394] pg/mL, p = 0.005) than the high TAPSE/PASP group. A significantly greater proportion of the low TAPSE/PASP group had atrial fibrillation (49% vs. 32%, p < 0.001) and renal dysfunction (estimated glomerular filtration rate, 46 [26-66] vs. 58 [32-76] mL/min/1.73 m², p = 0.003) compared with the high TAPSE/PASP group. The low TAPSE/PASP group showed significantly higher rates of all-cause mortality and HF rehospitalization than the high TAPSE/PASP group (log-rank p < 0.001). Multivariate analysis confirmed that a TAPSE/PASP ratio < 0.54 mm/mmHg was an independent predictor of the primary endpoint (hazard ratio, 2.242; 95% confidence interval, 1.492-3.370; p < 0.001). At the one-year post-discharge follow-up, patients in the low TAPSE/PASP group were more likely to have inadequate recovery of RV-PA coupling than those in the high TAPSE/PASP group. The TAPSE/PASP ratio is a useful non-invasive prognostic indicator in patients with HFmrEF. This ratio may contribute to early risk stratification and treatment decision-making.