Outcomes of medically managed patients with myocardial infarction

Abstract

Aims: The purpose of this study was to compare outcomes associated with medical management of ST-elevation myocardial infarction and non-ST-elevation myocardial infarction patients presenting to hospitals with and without onsite catheterization facilities. Methods All patients ( n=25,921) with ST-elevation myocardial infarction ( n=10,563) or non-ST-elevation myocardial infarction ( n=15,358) in Alberta, Canada between April 2010–March 2016 were categorized according to availability of catheterization facilities at the hospital they presented to and their management strategy (medically managed without coronary angiography or medically managed after coronary angiography). Results: Overall, 51% presented to hospitals without catheterization facilities; and 34% were managed medically (18% without coronary angiography, and 16% after coronary angiography). Rates of medical management were higher at hospitals without versus those with catheterization facilities (43% vs. 24%, p<0.01). However, both the rate of presentation to hospitals without catheterization facilities (70% non-ST-elevation myocardial infarction, 24% ST-elevation myocardial infarction, p<0.01) and medical management (45% non-ST-elevation myocardial infarction, 18% ST-elevation myocardial infarction, p<0.01) differed by myocardial infarction type. The lack of catheterization facilities at the presenting hospital had no association with in-hospital mortality in patients medically managed without coronary angiography, but was associated with a lower risk of mortality among patients medically managed after coronary angiography. However, the latter benefit was restricted to non-ST-elevation myocardial infarction patients only (adjusted hazard ratio 0.43, 95% confidence interval: 0.25–0.76). Conclusion: The availability of catheterization facilities at the hospital at which non-ST-elevation myocardial infarction and ST-elevation myocardial infarction patients presented influenced their likelihood of being medically managed, but was not associated with adverse short- or long-term mortality outcomes.