Maximum Troponin As an Independent Predictor of 30- and 90-day Mortality in Type 2 Myocardial Infarction

Type 2 myocardial infarction (Type 2 MI) is increasingly recognized among older adults and individuals with multiple comorbidities. We evaluated the association between maximum troponin levels and 30- and 90-day all-cause mortality using both continuous values and clinically meaningful thresholds.

We conducted a retrospective cohort study using the Medical Information Mart for Intensive Care IV database. Our analysis focused on patients with Type 2 MI, with maximum troponin level being the primary exposure of interest. We examined troponin's association with both 30-day and 90-day mortality, treating it as a continuous variable and categorizing it into thresholds: 10×, 100×, and 1000× the upper limit of normal (ULN), using 0.04 ng/mL (99th percentile of ULN) as the reference group. 1398 patients met our inclusion criteria.

Maximum troponin was an independent predictor of 30-day mortality and 90-day mortality after adjusting for confounders ( P = 0.018, P = 0.016, respectively). Compared with the reference group (<0.04 ng/mL), the relative risks of 30-day mortality were 1.39 [95% confidence intervals (CI), 0.89-2.17] for 10× ULN, 1.72 (95% CI, 1.10-2.71) for 10-100× ULN, 1.85 (95% CI, 1.16-2.95) for 100-1000× ULN, and 2.45 (95% CI, 1.31-4.57) for >1000× ULN. A similar pattern was seen for 90-day mortality, with relative risks of 1.28 (95% CI, 0.89-1.96), 1.76 (95% CI, 1.22-2.69), 1.63 (95% CI, 1.09-2.54), and 2.07 (95% CI, 1.05-3.35), respectively.

Higher troponin levels are independently associated with increased short- and intermediate-term mortality in Type 2 MI, supporting the potential use of troponin thresholds for risk stratification in this high-risk population.