Impact of Acute Kidney Injury on In-Hospital Outcomes of Patients With Acute Myocardial Infarction ― Results From the Japanese Registry of Acute Myocardial Infarction Diagnosed by Universal Definition (J-MINUET) Substudy ―

BACKGROUND: Acute kidney injury (AKI) is associated with poor outcome after acute myocardial infarction (AMI), but whether hemodynamic status at presentation influences this prognostic significance is unknown. METHODS AND RESULTS: A total of 2,798 AMI patients admitted within 48 h after symptom onset and who underwent urgent coronary angiography were enrolled in the present study. AKI was defined as an increase in serum creatinine ≥0.3 mg/dL or ≥50% within 48 h during hospitalization. Patients were classified into 3 groups according to Killip class on admission: Killip 1, n=2,164; Killip 2-3, n=366; and Killip 4, n=268. AKI occurred more frequently with increasing Killip class (Killip 1, 2-3, and 4: 6.3%, 15.3%, and 31.3%, respectively; P<0.001). AKI was associated with increased in-hospital mortality, regardless of Killip class (non-AKI and AKI patients: 1.1% vs. 6.6% in Killip 1; 5.2% vs. 35.7% in Killip 2-3, and 28.8% vs. 45.2% in Killip 4, P<0.01 for all). On multivariate analysis, the adjusted OR of AKI for in-hospital mortality in Killip 1, Killip 2-3, and Killip 4 were 3.79 (95% CI: 1.54-9.33, P=0.004), 5.35 (95% CI: 2.67-10.7, P<0.001), and 1.48 (95% CI: 0.94-2.35, P=0.093), respectively. CONCLUSIONS: In AMI patients undergoing urgent coronary angiography, AKI was significantly associated with increased in-hospital mortality in Killip 1 as well as Killip 2-3 at presentation, but not in Killip 4.