ST-elevation myocardial infarction diagnosed after hospital admission

Background: Treatment times for ST-elevation myocardial infarction (STEMI) patients presenting to percutaneous coronary intervention hospitals have improved dramatically over the past 10 years, particularly for patients using emergency medical services. Limited data exist regarding treatment times and outcomes for patients who develop STEMI after hospital admission.

Methods and results: With the use of a comprehensive prospective regional STEMI program database, we evaluated the characteristics and outcomes for patients who develop STEMI after hospital admission. Of the 3795 consecutive STEMI patients treated by the use of the Minneapolis Heart Institute regional STEMI program from March 2003 to January 2013, 990 (26.1%) presented initially to the percutaneous coronary intervention facility, including 640 arriving via emergency medical services, 267 self/family driven, and 83 already admitted to the hospital. Patients with in-hospital presentation were older with higher body mass indexes, were more likely to have hypertension, and to present with pre-percutaneous coronary intervention cardiac arrest and cardiogenic shock. Door-to-balloon times (diagnostic ECG-to-balloon for in-hospital patients) were longer than for patients using emergency medical services (76 versus 51 minutes; P<0.001), but similar to self/family-driven patients (76 versus 66 minutes; P=0.13). In-hospital patients had longer lengths of stay (5 versus 3 versus 3 days; P<0.001) and higher 1-year mortality (16.9% versus 10.3% versus 7.1%; P=0.032). These patients frequently had high-risk and complex reasons for admission, including 30.1% with acute coronary syndrome, 22.9% postsurgery, 13.3% respiratory failure, and 8.4% ventricular fibrillation.

Conclusions: Patients who develop STEMI while in-hospital represent a unique, high-risk subset of patients. They have increased treatment time and lengths of stay and higher mortality rates than the patients presenting via emergency medical services or who are self/family driven.