In-Hospital Mortality in Hemorrhagic Myocardial Infarction.

Background: Advances in acute ST-elevation myocardial infarction (STEMI) care have substantially decreased in-hospital mortality; however, in absolute terms, in-hospital mortality still remains high. Reperfusion injury, particularly intramyocardial hemorrhage following primary percutaneous coronary intervention (PCI), is a major predictor of adverse cardiovascular outcomes in the long term, but whether it contributes to in-hospital mortality is not known.

Methods: We performed a multicenter study to investigate the use of post-PCI high-sensitivity cardiac troponin I (hs-cTn-I) as a diagnostic tool to identify hemorrhagic myocardial infarction (MI) by determining hourly hs-cTn-I thresholds (every hour up to 12 hours, and at 16, 20, 24, and 48 hours post-PCI). We then investigated the relationship between patients classified as having hemorrhagic MI based on post-PCI hs-cTn-I cutoff values and in-hospital mortality using STEMI registries containing information about 6180 patients across seven hospitals in a single large health system in the United States.

Results: We enrolled 154 patients in a discovery cohort and 53 patients in a validation cohort. Hemorrhagic MI was diagnosed by cardiac magnetic resonance imaging. Post-PCI hs-cTn-I cutoff values for the determination of hemorrhagic MI were time dependent, with a sensitivity greater than 0.91, a specificity greater than 0.86, and an area under the curve (AUC) greater than 0.92 over the first 10 hours post-PCI, decreasing to a sensitivity greater than>0.84, a specificity greater than 0.80, and an AUC greater than 0.84 thereafter. The STEMI registry analysis demonstrated that patients classified as having hemorrhagic MI based on hs-cTn-I cutoff values had a 2.81-fold greater risk for in-hospital mortality than those classified as having had nonhemorrhagic MI (adjusted odds ratio, 2.81; 95% confidence interval, 2.17 to 3.64).

Conclusions: Post-PCI troponin kinetics may have the potential to diagnose hemorrhagic MI, which was associated with in-hospital mortality. (Funded by the National Institutes of Health National Heart, Lung, and Blood Institute (grant numbers HL133407, HL136578, and HL147133) and others; ClinicalTrials.gov ID, NCT05872308).