Right Ventricular to Pulmonary Arterial Uncoupling Is Associated With 1-Year Mortality in ST-Segment Elevation Myocardial Infarction

BACKGROUND: Right ventricular (RV)-pulmonary arterial (PA) coupling, a measure of RV function in relation to pulmonary afterload, has emerged as a promising prognostic marker in critically ill patients and can be readily assessed using echocardiography. OBJECTIVES: The aim of this study was to evaluate the prognostic significance of RV-PA coupling in patients presenting with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention. METHODS: This post hoc analysis of a retrospective study analyzed 973 STEMI patients (derivation and validation cohorts) undergoing primary percutaneous coronary intervention between 2014 and 2023 (median follow-up duration 4.2 years; Q1-Q3: 2.1-6.7 years). RV-PA uncoupling was assessed using echocardiography via the ratio of tricuspid annular plane systolic excursion (TAPSE) to systolic pulmonary artery pressure (sPAP). Using maximally selected log-rank statistics, a cutoff of 0.405 mm/mm Hg for TAPSE/sPAP ratio was identified, effectively stratifying patients into high- and low-risk groups. RESULTS: As confirmed in an external validation cohort, patients with RV-PA uncoupling showed significantly higher 1-year all-cause mortality compared with those with preserved RV-PA coupling (33.30% [95% CI: 4.65%-53.40%] vs 3.04% [95% CI: 1.40%-4.65%]; HR for 1-year mortality: 12.60; 95% CI: 4.49-35.40; P < 0.001). TAPSE/sPAP ratio outperformed TAPSE alone in predicting 1-year mortality, as demonstrated by receiver-operating characteristic curve analysis (area under the curve: 0.732 [95% CI: 0.643-0.821] vs 0.643 [95% CI: 0.537-0.732]; P = 0.018). Multivariate analysis confirmed that RV-PA uncoupling independently predicted 1-year mortality. CONCLUSIONS: This study highlights the importance of hemodynamic equilibrium between the RV and pulmonary circulation in STEMI patients. RV-PA uncoupling (TAPSE/sPAP ratio < 0.405 mm/mm Hg) is an independent predictor of 1-year all-cause mortality in these patients, aiding in early risk stratification.