In AASK Patients, ESRD Risk Exceeds Mortality

African American patients with hypertensive nephrosclerosis are more likely to develop end stage renal disease (ESRD) than they are to die or develop cardiovascular disease (CVD), according to data from the African American Study of Kidney Disease and Hypertension (AASK) reported in the Journal of the American Society of Nephrology.

Of 1094 African American patients with hypertensive nephrosclerosis enrolled in AASK, 764 had no events during an initial trial phase, from 1996 to 2001. Of these, 691 enrolled in a subsequent cohort phase, from 2002 through 2007. Eleven-year follow-up data were used to compare the rate of incident ESRD with total or CVD mortality and a composite of CVD death and hospitalization.

There were 59 CVD-related and 118 non-CVD-related deaths during follow-up. The rate of incident ESRD was 3.9/100 patient-years. This compared to total mortality of 2.2/100 patient years, CVD mortality of 0.8/100 patient-years, and a composite CVD outcome rate of 3.2/100 patient-years.

Overall, patients were five times more likely to develop ESRD than to die of CVD. The risk of ESRD exceeded mortality risk across subgroups based on age, sex, income, education, history of CVD, baseline proteinuria, and baseline kidney function.

African Americans with ESRD have lower CVD morbidity and mortality than white patients, but it has been unclear whether a similar racial difference applies to patients with chronic kidney disease. The AASK study provides an opportunity to assess long-term outcomes in African American patients with hypertensive nephrosclerosis and good blood pressure control.

The results suggest that these patients are more likely to have progression to ESRD than death from any cause, death from CVD, or a major CVD event. The findings may lend new insights into the relationship between high blood pressure and kidney disease in African Americans, and into reported racial differences in ESRD. Further study is needed to evaluate possible explanations for the lower cardiovascular mortality in this high-risk minority population [Alves TP, et al. Rate of ESRD exceeds mortality among African Americans with hypertensive nephrosclerosis. J Am Soc Nephrol 2010; 21:1361–1369].