Cardiovascular outcomes in the African American Study of Kidney Disease and Hypertension (AASK) Trial.

BACKGROUND

Patients with chronic kidney disease are at increased risk for cardiovascular (CV) events.

METHODS

We randomly assigned 1,094 African Americans with hypertensive nephrosclerosis (glomerular filtration rate [GFR], 20 to 65 mL/min/1.73 m(2) [0.33 to 1.08 mL/s]) to initial antihypertensive treatment with either: (1) a beta-blocker, metoprolol; (2) an angiotensin-converting enzyme inhibitor, ramipril; or (3) a dihydropyridine calcium channel blocker, amlodipine, and either a usual-blood pressure (BP) or low-BP treatment goal. Using a design powered to detect renal outcome differences, we compared the effect of treatment on the CV event rate (cardiac death, myocardial infarction, stroke, and heart failure) during a mean follow-up period of 4.1 years and determined baseline factors that predict CV outcomes.

RESULTS

Thirty-one patients died of CV disease (0.7%/patient-year), and 149 patients experienced at least 1 CV outcome (3.3%/patient-year). Overall, 202 CV events (4.5%/patient-year) occurred. The CV outcome rate was not related significantly to randomized interventions. In multivariable analyses, 7 baseline risk factors remained independently associated with increased risk for the CV composite outcome after controlling for age, sex, baseline GFR, and baseline proteinuria group: pulse pressure, duration of hypertension, abnormal electrocardiogram result, non-high-density lipoprotein cholesterol level, serum urea nitrogen level, urine protein-creatinine ratio, urine sodium-potassium ratio, and annual income less than 15,000 dollars.

CONCLUSION

Neither randomized class of antihypertensive therapy nor BP level had a significant effect on the occurrence of CV events, possibly because of limited power. However, this analysis identifies unique and potentially modifiable CV risk factors in this high-risk cohort.