Prognostic Value of the TAPSE/sPAP Ratio in Patients with Type 2 Respiratory Failure: Insights into Right Ventricular-Pulmonary Arterial Coupling and Clinical Outcomes.

Abstract

Background/Objectives : Type 2 respiratory failure (T2RF) is associated with significant morbidity and mortality, partly driven by cardiopulmonary interactions and right ventricular (RV) dysfunction. The tricuspid annular plane systolic excursion to systolic pulmonary artery pressure (TAPSE/sPAP) ratio has emerged as a non-invasive marker of RV-pulmonary arterial (RV-PA) coupling; however, its prognostic value in T2RF remains insufficiently explored. This study aimed to evaluate the association between TAPSE/sPAP and short-term clinical outcomes in hospitalized T2RF patients. Methods : In this retrospective cohort study, 182 adult patients hospitalized with T2RF between January 2024 and December 2025 were included. Patients were followed from hospital admission until discharge or death, and survival status was additionally evaluated up to 60 days after admission using hospital electronic medical records and follow-up databases for Kaplan-Meier survival analysis. Complete follow-up data were available for all included patients. Demographic, clinical, laboratory, and transthoracic echocardiographic data were analyzed. Patients were stratified into low and high TAPSE/sPAP groups. The primary outcome was in-hospital mortality; secondary outcomes included 60-day all-cause mortality, non-invasive ventilation (NIV) failure, intensive care unit (ICU) admission, and length of hospital stay. Statistical analyses included receiver operating characteristic (ROC) curves, multivariable logistic regression, calibration assessment, and decision curve analysis. Results : Patients with a low TAPSE/sPAP ratio had significantly higher in-hospital mortality (38.6% vs. 12.8%, p < 0.001), higher rates of NIV failure and ICU admission, and longer hospital stays. TAPSE/sPAP demonstrated the highest predictive performance for mortality (AUC: 0.82, 95% CI: 0.75-0.88), outperforming conventional echocardiographic parameters. In multivariable analysis, TAPSE/sPAP remained an independent predictor of mortality (OR: 1.48 per 0.1 decrease, p < 0.001). The model showed good calibration (Hosmer-Lemeshow p = 0.62), and decision curve analysis confirmed its clinical utility with a higher net benefit across a wide range of threshold probabilities. Conclusions : The TAPSE/sPAP ratio was independently associated with in-hospital mortality and adverse clinical outcomes in patients with T2RF, reflecting impaired RV-PA coupling. As a readily obtainable non-invasive echocardiographic parameter, it demonstrated promising prognostic value for risk stratification in this population. However, given the retrospective single-center design of the study, these findings should be considered hypothesis-generating and require confirmation in prospective multicenter studies before routine clinical implementation can be recommended.