Impact of contrast-induced acute kidney injury after percutaneous coronary intervention on short- and long-term outcomes: Pooled analysis from the HORIZONS-AMI and ACUITY trials

Background - Contrast-induced acute kidney injury (CI-AKI), defined as a serum creatinine increase ≥0.5 mg/dL or ≥25% within 72 hours after contrast exposure, is a common complication of procedures requiring contrast media and is associated with increased short- and long-term morbidity and mortality. Few studies describe the effects of CI-AKI in a large-scale acute coronary syndrome population, and the relationship between CI-AKI and bleeding events has not been extensively explored. We sought to evaluate the impact of CI-AKI after percutaneous coronary intervention in patients presenting with acute coronary syndrome. Methods and Results - We pooled patient-level data for 9512 patients from the percutaneous coronary intervention cohorts of the Harmonizing Outcomes With Revascularization and Stents in Acute Myocardial Infarction (HORIZONS-AMI) and Acute Catheterization and Urgent Intervention Triage Strategy (ACUITY) multicenter randomized trials. Patients were classified according to CI-AKI development, and cardiovascular outcomes at 30 days and 1 year were compared between groups. A total of 1212 patients (12.7%) developed CI-AKI. Patients with CI-AKI were older, with a more extensive comorbidity profile than without CI-AKI. Multivariable analysis confirmed several previously identified predictors of CI-AKI, including diabetes mellitus, contrast volume, age, and baseline hemoglobin. Mortality rates were significantly higher in the CI-AKI group at 30 days (4.9% versus 0.7%; P<0.0001) and 1 year (9.8% versus 2.9%; P<0.0001), as were rates of 1-year myocardial infarction, definite/probable stent thrombosis, target lesion revascularization, and major adverse cardiac events. Major bleeding (13.8% versus 5.4%; hazard ratio, 2.64; 95% confidence interval, 2.21-3.15; P<0.0001) was also higher in patients with CI-AKI. After multivariable adjustment, results were unchanged. Conclusions - CI-AKI after percutaneous coronary intervention in patients presenting with acute coronary syndrome is independently associated with increased risk of short- and long-term ischemic and hemorrhagic events.