Right ventricular-pulmonary coupling and tissue hypoperfusion: a combined echocardiographic and metabolic approach to prognosticate cardiogenic shock.

BACKGROUND: Cardiogenic shock (CS) remains a high-mortality condition. Effective risk stratification is crucial for guiding management. This study evaluated the combined prognostic utility of the tricuspid annular plane systolic excursion(TAPS) to pulmonary artery systolic pressure (PASP) ratio, a measure of right ventricular-pulmonary coupling, and lactate, a marker of tissue hypoperfusion, in intensive care unit (ICU) patients with CS. METHODS: A retrospective cohort study was conducted on 221 ICU patients diagnosed with CS (SCAI shock stages B-E). Echocardiographic parameters (including TAPS/PASP) and arterial lactate levels were obtained within 24 h of diagnosis. The primary outcome was 28-day mortality. Univariate and multivariate Cox proportional hazards regression, Kaplan-Meier survival analysis, and receiver operating characteristic (ROC) curve analysis were performed. RESULTS: Both TAPS/PASP ratio (HR = 0.689, p = 0.003) and lactate (HR = 1.498, p = 0.003) were independently associated with 28-day mortality. Patients with low TAPS/PASP and high lactate had significantly lower survival. A combined model incorporating both parameters demonstrated superior predictive performance for 28-day mortality (AUC = 0.703) compared to TAPS/PASP (AUC = 0.671) or lactate (AUC = 0.650) alone. A non-linear relationship was observed between TAPS/PASP and lactate. CONCLUSION: The combined assessment of TAPS/PASP ratio and lactate levels provides enhanced prognostic information in patients with cardiogenic shock. This integrated approach, incorporating both cardiac function and metabolic biomarkers, may improve risk stratification and facilitate more targeted therapeutic interventions in this high-risk population.