(taken directly from the application) The African-American Study of Kidney Disease and Hypertension (AASK) is a multi-center, randomized double-blind controlled trial designed to determine whether long-term lowering of blood pressure to two different levels of mean arterial pressure (MAP) less than 92 versus 102-107 millimeters of mercury (mmHg) with a calcium channel blocker, an angiotensin converting enzyme inhibitor, or a beta-blocker can prevent deterioration in renal function in African-Americans with hypertensive nephrosclerosis and chronic renal insufficiency. The full-scale trial will involve 900 adult African-Americans of both sexes with hypertensive nephrosclerosis and a baseline glomerular filtration rate of 25-70 milliliters per minute per 1.73 meters squared. The study is designed to answer two key questions in this study population: 1) can long-term blood pressure control (102-107 mmHg) slow progression of renal disease; and 2) is strict blood pressure control (mean arterial pressure less than (92 mmHg) more effective than usual control (102-107 mmHg) in preserving renal function? During the pilot study for AASK, the applicant reports that they have recruited and randomized 11 patients over a six and one- half month period. Eight of these patients have undergone successful renal biopsy. They report a 100 percent retention of randomized subjects with no serious adverse events thus far, and that the participants have been 100 percent compliant with protocol procedures and greater than 90 percent compliant with medications and have been able to achieve the blood pressure goal level in 9 out of 11 patients thus far. The team of investigators appears to have worked cooperatively with the data coordinating center and has been able to transmit data in a timely and efficient manner. The investigators report preliminary studies which suggest that the AASK protocol is acceptable and well tolerated by participants, and is feasible for application to the full- scale trial. The trial is unique because for the first time: 1) African- Americans with a single progressive renal disease will be studied in a multi-center trial; 2) the relative efficacy and safety of a calcium channel blocker, an angiotensin-converting enzyme inhibitor and a beta- blocker for preserving renal function will be assessed; and 3) investigators will obtain an assessment of the best methodologies for recruitment and retention of this population in a long-term clinical trial. The goal of the study is to provide a means by which the incidence of end stage renal disease can be effectively forestalled or prevented altogether in this high-risk population.
