Impact of In-Hospital STEMI on Reperfusion Times and Clinical Outcomes

BACKGROUND: ST-segment–elevation myocardial infarction (STEMI) is uncommon among inpatients already admitted to the hospital for other indications. Prior studies reported significant differences in clinical characteristics and outcomes of patients who develop STEMI while hospitalized versus those who present with out-of-hospital STEMI. However, prior studies were small or not contemporary. METHODS: We compared the characteristics and outcomes of patients presenting with STEMI at the time of hospital admission (preadmission STEMI) versus in-hospital STEMI (occurring during the hospitalization) using data from the National Cardiovascular Data Registry Chest Pain-MI Registry from 2019 to 2022. RESULTS: A total of 112 590 patients (3.8% in-hospital STEMI, 96.2% preadmission STEMI) from 670 hospitals were included. Patients with in-hospital STEMI were significantly older (median age, 67 versus 63 years), more likely to be diabetic (37.6% versus 29.6%) and have CHF (13.7% versus 6.0%) compared with preadmission STEMI patients (all P <0.001). The median (interquartile range) time from ECG to first device activation (81 minutes 61–110 versus 69 55–84; P <0.0001) and time from cath laboratory arrival to first device time (28 minutes 21–39 versus 23 18–30; P <0.001) were significantly longer for in-hospital compared with preadmission STEMI patients. The incidence of major bleeding (25.5% versus 7.1%), cardiogenic shock (19.7% versus 7.0%), and cardiac arrest (22.3% versus 7.3%) were all significantly higher in the in-hospital STEMI cohort (all P <0.001), as was mortality (25.9% versus 5.6%; adjusted OR, 5.7 95% CI, 5.0–6.4; P <0.001). CONCLUSIONS: Patients who experience in-hospital STEMI represent a high-risk group, with significantly longer times from the diagnostic ECG to primary percutaneous coronary intervention, more complications, and higher mortality.