Associations Between Electrocardiographic Features and Type 1 and Type 2 Myocardial Infarction in Critically Ill...

Electrocardiographic (ECG) findings are commonly used to evaluate myocardial infarction (MI), yet their ability to distinguish Type 1 from Type 2 MI in critically ill patients remains uncertain. We conducted a retrospective observational study using the MIMIC-IV database to examine associations between ECG features and MI subtype among adult intensive care unit patients with elevated troponin and ICD-10-defined Type 1 or Type 2 MI. Structured ECG interpretation features, including ST segment changes, T-wave abnormalities, QTc prolongation, and arrhythmia were analyzed using multivariable logistic regression. Among 2,159 patients, ST segment elevation was uncommon but significantly associated with Type 1 MI (9.4% vs 3.1%; adjusted odds ratios 2.48, 95% CI 1.31 to 5.15), whereas QTc prolongation was highly prevalent-particularly in Type 2 MI (66.2% vs 52.9%)-and independently associated with lower odds of Type 1 MI (adjusted odd ratios 0.63, 95% CI 0.49 to 0.81). Overall model discrimination was modest (area under the curve 0.73), but diagnostic performance was characterized by near-perfect sensitivity and very low specificity due to substantial class imbalance favoring Type 1 MI. In conclusion, ECG features alone provide limited clinical and mechanistic utility for differentiating Type 1 from Type 2 MI in critically ill patients and should be interpreted within the broader clinical and physiologic context.