Limited Predictive Value of TIMI Score for In-Hospital Mortality in NSTEMI: Cardiogenic Shock as a Stronger Independent Predictor

Abstract

Objectives: This study aimed to evaluate the reliability and predictive strength of the Thrombolysis in Myocardial Infarction (TIMI) risk score for in-hospital mortality among patients with Non-ST-Segment Elevation Myocardial Infarction (NSTEMI) admitted to Pakistan's largest tertiary care cardiac center. Methodology: This retrospective cohort study was conducted at the National Institute of Cardiovascular Diseases (NICVD), Karachi, Pakistan. Data were extracted from a prospectively maintained hospital-based registry. Records of patients who underwent percutaneous coronary intervention (PCI) following admission for NSTEMI between September 2022 and August 2023 were reviewed. Results: A total of 717 NSTEMI patients were included, of whom 77.7% were male, with a mean age of 55 ± 10.2 years and an average body mass index (BMI) of 27.7. Common comorbidities included hypertension (61.6%) and diabetes mellitus (31.5%). Electrocardiographic findings showed ST-segment deviation ≥0.5 mm in 45% of cases. In-hospital mortality was observed in 2% of the cohort. The TIMI score demonstrated poor predictive performance for in-hospital mortality (AUC = 0.751, P = 0.001). Multivariate analysis identified cardiogenic shock as an independent predictor of in-hospital mortality (OR 102.96, P < 0.001). Conclusion: The findings suggest that the TIMI risk score lacks a significant association with in-hospital mortality in NSTEMI patients. Conversely, cardiogenic shock emerged as a strong independent predictor of in-hospital mortality. These results highlight the need to re-evaluate risk stratification tools in this population.