Association of Anemia With Outcomes Among ST-Segment-Elevation Myocardial Infarction Patients Receiving Primary Percutaneous Coronary Intervention

BACKGROUND: Anemia may confer a poor prognosis among patients with the acute coronary syndrome. However, few data exist on the association of anemia with in-hospital outcomes, including bleeding, among ST-segment-elevation myocardial infarction patients receiving primary percutaneous coronary intervention. METHODS AND RESULTS: We identified 1919 ST-segment-elevation myocardial infarction patients who had undergone primary percutaneous coronary intervention within the Vancouver Coastal Health Authority (2007-2016) of whom 322 (16.8%) had anemia on admission. Betweengroup differences in (unadjusted) in-hospital outcomes, including heart failure, cardiogenic shock, major bleeding, and death were examined. Spearman correlation (r s) and multivariate logistic regression were used to evaluate the relationship of anemia on admission with clinical outcomes. Compared with nonanemic patients, anemic patients were more likely to have preexisting hypertension, diabetes mellitus, and prior myocardial infarction. Anemic patients had higher unadjusted rates of in-hospital death (8.1% versus 3.7%; P< 0.001), bleeding (18.2% versus 9.4%; P< 0.001), and were more likely to develop heart failure (odds ratio [ OR], 1.62; 95% CI, 1.19-2.22), shock (OR, 2.35; 95% CI, 1.62-3.40), or cardiac arrest (OR, 1.94; 95% CI, 1.10-3.40) during their hospital stay. Baseline anemia was independently associated with major bleeding (OR, 1.78; 95% CI, 1.25-2.56) but not all-cause mortality (OR, 0.99; 95% CI, 0.57-1.73). There was no significant correlation between anemia and overall reperfusion times (OR, 0.95; 95% CI, 0.74-1.22). CONCLUSIONS: In a contemporary ST-segment-elevation myocardial infarction cohort receiving primary percutaneous coronary intervention, nearly 1 in 5 patients were anemic. Anemia was associated with increased comorbidities and higher-risk features on presentation and was independently associated with subsequent major in-hospital bleeding but not all-cause mortality. These results suggest that anemic ST-segmentelevation myocardial infarction patients may safely receive timely primary percutaneous coronary intervention but with particular consideration for bleeding avoidance strategies.