Association between a composite metabolic index and mortality in critically ill patients with pulmonary hypertension: a retrospective cohort study.

Pulmonary hypertension (PH) is a heterogeneous condition with variable prognosis across World Health Organization (WHO) subtypes. The fasting blood glucose to high-density lipoprotein cholesterol (FBG/HDL-C) ratio has been suggested as a metabolic predictor of adverse outcomes in critically ill patients, but its prognostic value in PH remains unclear. This retrospective cohort included 281 ICU patients with pulmonary hypertension (PH) from MIMIC-IV (2008-2022). Patients were divided into tertiles based on ln(1 + FBG/HDL-C). The primary endpoint was 90-day all-cause mortality, which was assessed using Cox proportional hazards regression, with exploratory subgroup analyses by WHO PH groups. In fully adjusted models, patients in the highest tertile of ln(1 + FBG/HDL-C) had higher 90-day mortality than those in the lowest tertile (HR = 3.30, 95% CI: 1.82, 5.97; p < 0.001). Elevated risk was observed across WHO PH Groups 1, 2, and 5, with the most statistically robust and clinically interpretable association in Group 2 (HR = 2.66, 95% CI: 1.40, 5.05; p = 0.003). Elevated FBG/HDL-C ratio was independently associated with 90-day mortality, with the association in Group 2 being the most statistically stable and clinically interpretable.