Renal insufficiency and cardiovascular events in postmenopausal women with coronary heart disease

OBJECTIVES: This study sought to determine the independent association of renal insufficiency with cardiovascular risk among women with known coronary heart disease (CHD). BACKGROUND: Although patients with end-stage renal disease and proteinuria are at high risk for cardiovascular events, little is known about the cardiovascular risk associated with moderate renal insufficiency. METHODS: The Heart and Estrogen/progestin Replacement Study (HERS) was a clinical trial among 2,763 women with coronary disease who were randomized to conjugated estrogen plus progestins or identical placebo and followed for a mean of 4.1 years. Women were categorized as having normal renal function (creatinine < 1.2 mg/dl; n = 2,012), mild renal insufficiency (1.2 mg/dl to 1.4 mg/dl; n = 567) and moderate renal insufficiency (>1.4 mg/dl; n = 182). We examined the independent association of renal function with incident cardiovascular events including CHD death, nonfatal myocardial infarction, hospitalization for unstable angina, stroke and transient ischemic attacks. RESULTS: Compared with women with normal renal function, those with mild and moderate renal insufficiency were older, more likely to be black, have a history of hypertension and diabetes and have higher serum levels of triglycerides and lipoprotein(a). After multivariate adjustment, both mild (relative hazards [RH] = 1.24; 95% confidence interval [CI]: 1.0 to 1.5) and moderate renal insufficiency (RH = 1.57; 95% CI: 1.2 to 2.1) were independently associated with increased risk for cardiovascular events compared with women with normal renal function. CONCLUSIONS: Renal insufficiency is an independent risk factor for cardiovascular events in postmenopausal women with known coronary artery disease. Renal function may add helpful information to CHD risk stratification.