Short-Term Outcomes of Acute Myocardial Infarction in Patients With Acute Kidney Injury

Abstract

Background— Acute kidney injury (AKI) is a risk factor for long-term adverse outcomes, including acute myocardial infarction and death. However, the relationship between severity of AKI and in-hospital outcomes in the setting of acute myocardial infarction has not been well documented. Methods and Results— The study population (n=59 970) was drawn from the Acute Coronary Treatment and Intervention Outcomes Network (ACTION) Registry–Get With the Guidelines (GWTG), a nationwide sample of myocardial infarction patients admitted to 383 hospitals in the United States between July 2008 and September 2009. AKI was defined using absolute changes in serum creatinine (SCr; peak SCr minus admission SCr) and categorized as no AKI (SCr change, <0.3 mg/dL), mild AKI (SCr change, 0.3–<0.5 mg/dL), moderate AKI (SCr change, 0.5–<1.0 mg/dL), and severe AKI (SCr change, ≥1.0 mg/dL). Overall, 16.1% had AKI, including 6.5% with mild AKI, 5.6% with moderate AKI, and 4.0% with severe AKI. In-hospital mortality rates for those with mild, moderate, and severe AKI were 6.6%, 14.2%, and 31.8% compared with 2.1% in those without AKI. The odds ratios for in-hospital death were 2.4 (95% confidence interval, 2.0–2.7), 4.5 (95% confidence interval, 3.9–5.1), and 12.6 (95% confidence interval, 11.1–14.3) for mild, moderate, and severe AKI compared with those without AKI. Although patients with AKI were less likely to undergo early invasive care or to receive antiplatelet therapies, rates of major bleeding ranged from 8.4% (no AKI) to 32.7% (severe AKI). Conclusion— AKI is common and associated with mortality and bleeding, underscoring the importance of efforts to identify risk factors and to prevent AKI in acute myocardial infarction care.