Quality of Care and Outcomes Among Patients With Acute Myocardial Infarction by Level of Kidney Function at Admission: Report From the Get With The Guidelines Coronary Artery Disease Program

Abstract

Many patients admitted for acute myocardial infarction (AMI) have chronic renal insufficiency. We studied the impact of chronic renal insufficiency on mortality and quality of inpatient care for AMI from the American Heart Association's Get With The Guidelines-Coronary Artery Disease Program. We hypothesized that mortality and quality of inpatient care would not vary with renal function. We examined in-hospital AMI performance measures by renal function based on glomerular filtration rate (GFR). Severity of renal insufficiency was categorized as normal (GFR ≥ 90 mL/min/1.73 m(2)), mild (GFR 60-90 mL/min/1.73 m(2)), moderate (GFR 30-60 mL/min/1.73 m(2)), severe (GFR 15-30 mL/min/1.73 m(2)), and kidney failure (GFR ≤ 15 mL/min/1.73 m(2) or dialysis). A total of 21721 patients from 291 sites were studied, with most data collected in 2008 to 2009. Multivariable regression analysis after adjusting for patient characteristics was performed and generalized estimating equations were used to account for within-hospital clustering. In-hospital mortality and quality of inpatient care were assessed. Renal insufficiency was present in 82.0 percent of AMI patients. The adjusted odds ratio vs normal renal function for mortality increased with worsening renal function: 1.45 for mild renal insufficiency (95% confidence interval [CI]: 1.03-2.05, P = 0.03); 3.36 for moderate renal insufficiency (95% CI: 2.31-4.89, P < 0.0001); 5.43 for severe renal insufficiency (95% CI: 3.70-7.95, P < 0.0001); and 6.35 for kidney failure (95% CI: 4.48-9.01, P < 0.0001). Patients with renal insufficiency received less inpatient and discharge guideline-recommended therapy for AMI. Among AMI patients, mortality and guideline-recommended inpatient therapy correlated inversely with renal function. Adjusted mortality was equally poor among patients with severe renal dysfunction and on dialysis.