Prognostic value of the international normalized ratio-to-albumin ratio in coronary artery disease: A retrospective cohort study from the MIMIC-IV database.

Coronary artery disease (CAD) is a major cause of mortality in the intensive care units. The prothrombin time-international normalized ratio-to-albumin ratio (PTAR), integrating coagulation status and nutritional/inflammatory conditions, may provide additional prognostic information. This study aimed to evaluate the prognostic value of PTAR in predicting the mortality risk in critically ill patients with CAD. We conducted a retrospective cohort study using the Medical Information Mart for Intensive Care IV database to evaluate the relationship between PTAR and all-cause mortality. Adult CAD was categorized into quartiles according to PTAR levels. Cox proportional-hazards models were constructed to explore the independent association between PTAR and 28-day mortality, with progressive adjustment for potential confounders. Restricted cubic spline analysis, Kaplan-Meier survival curves, and receiver operating characteristic analysis were performed to assess dose-response patterns, survival differences, and predictive performance. Subgroup and interaction analyses were also conducted across the major clinical strata. Elevated PTAR levels were independently associated with increased mortality. The 28-day and 365-day all-cause mortality rates were 18.7% and 22.6%, respectively. Receiver operating characteristic analysis demonstrated a moderate discriminatory ability for PTAR (area under the curve = 0.667), which was significantly improved when combined with the Sequential Organ Failure Assessment score (area under the curve = 0.727, P < .001). Restricted cubic spline analysis revealed a nonlinear dose-response relationship between PTAR and mortality (P < .001). Subgroup analyses showed consistent results across most clinical strata, except for race. Elevated PTAR is independently and significantly associated with increased all-cause mortality in critically ill CAD patients. Its combination with the Sequential Organ Failure Assessment score improves the prognostic accuracy.