Background: It is unclear whether pre-existing cardiovascular disease or predisposition of the uremic state leads to the high cardiovascular morbidity and mortality associated with renal failure. We examined whether renal failure independently increases the risk of myocardial infarction and death.
Methods: A total of 8600 patients with variable glomerular filtration rate (GFR) at the time of coronary angiography participated in the Intermountain Heart Study. Coronary disease was defined as >or=70% stenosis. Modification of Diet in Renal Disease formula was used to calculate glomerular filtration rate (GFR). Cox regression models were used to compare outcomes.
Results: The mean GFR was 71 +/- 24 mL/min. There were 1320 (15%) deaths, 657 (9%) myocardial infarctions and 1776 (21%) death or myocardial infarctions over 3.2 +/- 1.9 years. Compared to the highest GFR quartile, the lowest GFR quartile (mean GFR 41 +/- 14 mL/min) was associated with higher risk for myocardial infarction (RR 1.43, 95% CI 1.15 to 1.78), death (RR 2.77, 95% CI 2.32 to 3.30) and death/myocardial infarction (RR 2.13, 95% CI 1.85 to 2.45) in multivariable models adjusted for age, sex, hypertension, hyperlipidemia, smoking, family history of coronary disease and diabetes. Even after further adjustment for coronary angiographic data and the choice of initial therapy, lowest GFR quartile was associated with increased risk of myocardial infarction (RR 1.51, 95% CI 1.21 to 1.88), death (RR 2.60, 95% CI 2.18 to 3.10) and death/myocardial infarction (RR 2.08, 95% CI 1.80 to 2.39).
Conclusions: Even moderate renal failure increases the risk of myocardial infarction and death independent of clinical variables, baseline angiographic evidence of coronary disease and therapy.