ST segment elevation myocardial infarction in patients hospitalized for non-cardiac conditions

Timely use of primary percutaneous coronary intervention (PCI) is the standard of care for patients with ST segment elevation myocardial infarction (STEMI). Most patients with STEMI present via emergency medical services or self-transport to the emergency department (ED) and relatively little is known about the minority of patients that develop STEMI while hospitalized for non-cardiac conditions. The objective of this study was to analyze treatment times and clinical outcome for in-hospital STEMI patients.

Two-hundred fifty-five patients with STEMI treated at Keck Medical Center of USC and Los Angeles County USC Medical Center from January, 2009 to December, 2013 were retrospectively analyzed. Demographics, treatment time intervals and clinical outcome were collected. Patients arriving via the ED (ED STEMI Group, n=228; 89%) were compared to patients that developed in-hospital STEMI (In-hospital STEMI Group, n=27; 11%).

Patients with in-hospital STEMI were similar in age, gender and associated medical conditions to ED STEMI patients. In-hospital STEMI patients were less likely to present with chest pain compared to ED STEMI patients, 5% vs. 79%, respectively, p<0.0001. Time from first abnormal electrocardiogram to device was 195±202min for in-hospital STEMI Group compared to door to device time of 88±64min for ED STEMI Group, p<0.001. Length of hospital stay was significantly longer for in-hospital STEMI Group compared to ED STEMI Group, 13±10 vs. 6.8±7.8days, respectively, p<0.001. In-hospital mortality was significantly higher for the in-hospital STEMI Group compared to the ED STEMI Group, 37% vs. 7%, respectively, p<0.001.

In-hospital STEMI patients have significant treatment delays and worse clinical outcome compared to STEMI patients that present via the emergency department. Additional efforts are required to promptly identify in-hospital patients that develop STEMI.