Risk factors for non-fatal myocardial infarction and cardiac death in incident dialysis patients

Abstract

The risks of major cardiac events in patients initiating long-term dialysis related to prior coronary disease and various other factors are not well known. We used United States Renal Data System data to analyse the outcomes of non-fatal myocardial infarction (MI) and cardiac death in incident dialysis patients from years 1997 through 2001 (n = 214 890). The presence of established coronary artery disease was determined from the Medical Evidence form, non-fatal MI events were determined from Medicare claims' data and cause of death was determined from the Death Notification form. Multivariable analyses were performed employing Cox proportional hazards models using demographics, co-morbidities, laboratory variables, prior erythropoietin use, body mass index and type of dialysis. In patients with prior coronary disease as compared to those without, the adjusted relative risk of non-fatal MI was 1.57 (95% CI, 1.5-1.65) and cardiac death was 1.16 (95% CI, 1.14-1.18). The 5-year cumulative incidence of non-fatal MI was 8.1 and 6% and cardiac death was 48.3 and 40.2%, in patients with and without prior coronary disease, respectively. Amongst important factors, blacks had a lower risk of non-fatal MI and cardiac death as compared to whites. A history of hypertension conferred a lower independent risk of cardiac death events. Lower haemoglobin, higher albumin and higher creatinine values each conferred a lower independent risk of non-fatal MI and cardiac death. Incident dialysis subjects with prior coronary disease have a risk of non-fatal MI greater by 57% and cardiac death by 16% as compared to subjects without prior coronary disease. In both populations, the competing risk of cardiac death is several-fold greater than that of non-fatal MI. There are several factors suggesting reverse epidemiology phenomena with respect to major cardiac events in the dialysis population.