The African American Study of Kidney Disease and Hypertension (AASK) trial: what more have we learned?

Abstract

The final results of the African American Study of Kidney Disease and Hypertension (AASK) have shown that the angiotensin-converting enzyme inhibitor ramipril was better than the beta blocker metoprolol or the dihydropyridine calcium channel blocker amlodipine in slowing the rate of glomerular filtration rate decline in African American patients with mild to moderate renal insufficiency. Of note, there was no difference between the 92 mm Hg or less (lower group) and the 102-107 mm Hg (usual) mean arterial pressure groups as regards the secondary clinical composite end point. The secondary clinical composite end point in this study comprised a threshold drop of at least 50% or 25 mL/min in glomerular filtration rate, death, or reaching end-stage renal disease. The final results from this study would suggest that reduction in blood pressure to levels below those currently advocated for cardiovascular risk reduction, although a clearly attainable goal in this population, does not provide readily identifiable benefits to African Americans with hypertensive nephrosclerosis. Importantly, this study provides the basis for the primary use of angiotensin-converting enzyme inhibitors in an African American population with the characteristics of those studied in AASK. It remains to be determined if this represents a class effect for all angiotensin-converting enzyme inhibitors.