Non–ST‐Segment–Elevation Myocardial Infarction Among Patients With Chronic Kidney Disease: A Propensity Score–Matched Comparison of Percutaneous Coronary Intervention Versus Conservative Management

BACKGROUND: Chronic kidney disease (CKD) remains an independent predictor of cardiovascular morbidity and mortality. CKD complicates referral for percutaneous coronary intervention (PCI) in non–ST‐segment–elevation myocardial infarction (NSTEMI) patients because of the risk for acute kidney injury and the need for dialysis, with American College of Cardiology/American Heart Association guidelines underscoring the limited data on these patients. METHODS AND RESULTS: Using the National Inpatient Sample to analyze hospitalizations in the United States from 2004 to 2014, we sought to assess PCI utilization and in‐hospital outcomes in NSTEMI admissions with CKD. NSTEMI admissions were identified by International Classification of Diseases, Ninth Edition, Clinical Modification (ICD‐9‐CM) code 410.7. CKD admissions were identified by ICD‐9‐CM code 585. Propensity score–matched cohorts of patients with NSTEMI were matched for age, sex, comorbidities, race, median household income, primary payer status, and hospital characteristics. Of 4 488 795 hospitalizations for NSTEMI, 31% underwent PCI. Overall, 89% of admissions had no CKD. In addition, 32% of NSTEMI admissions with no CKD and 23%, 14%, and 22% with CKD stages 3, 4, and 5 underwent PCI, respectively. Hospitalized NSTEMI patients with CKD stages 4 and 5 had 41% and 20% less likelihood, respectively, of undergoing PCI compared with those with no CKD. Among hospitalized NSTEMI patients with no CKD or CKD stage 3, 4, or 5, PCI‐treated groups had 63%, 57%, 39%, and 59% lower likelihood, respectively, of all‐cause, in‐hospital mortality compared with propensity score–matched medically managed groups. CONCLUSIONS: PCI use decreased among hospitalized NSTEMI patients as CKD severity increased, and all‐cause, in‐hospital mortality was greater for NSTEMI patients admitted with more severe CKD regardless of treatment strategy.