Renal dysfunction and ischemic heart disease mortality in a hypertensive population

OBJECTIVE: While recent studies indicate that renal dysfunction may be predictive of all-cause mortality and cardiovascular disease (CVD) outcomes in hypertensive individuals, there has been little attention to the specific association of ischemic heart disease (IHD) mortality and renal function. This study examines the relationship between IHD mortality and baseline glomerular filtration rate (GFR) (estimated by the Cockcroft and Gault formula) among treated hypertensive subjects. DESIGN: A prospective cohort study of participants in a worksite-based antihypertensive treatment program in New York City (1981-1999). PATIENTS: We studied 9929 subjects who had at least 6 months follow-up (mean 9.6 years) with a baseline serum creatinine. MAIN OUTCOME MEASURES: IHD death outcomes (n=343) ascertained from the National Death Index. RESULTS: Multivariate Cox proportional hazard models were constructed adjusting for known cardiovascular risk factors. Mean GFR of the cohort was 91.6 ml/min per 1.73 m. Those with lower GFR were more likely to be older, female, White, report a history of cardiovascular disease, have higher cholesterol and blood urea nitrogen values, and lower hemoglobin and body mass index than those with highest GFR. After adjustment for known cardiovascular risk factors, the risk of IHD death increased progressively as the GFR decreased. Hazard ratio for IHD mortality for each 10-unit reduction of estimated GFR below the normal threshold of >or=90 ml/min per 1.73 m was 1.33 (95% confidence interval 1.17, 1.50; P<0.001). CONCLUSIONS: The results of this study suggest an independent inverse association between estimated GFR and IHD mortality among treated hypertensive individuals.