There is a disproportionate number of Black Americans with hypertension and end-stage renal disease (ESRD) secondary to hypertension. Hypertension is the leading cause of ESRD in Black Americans. Despite this, there is little data addressing potential therapeutic maneuvers which may slow or halt development of hypertensive ESRD in this patient population. The goal of this project is to conduct a multi-center study to determine if angiotensin-converting enzyme inhibitors (CEI) or calcium channel blockers (CCB) protect the kidney from progressive damage in Black Americans with hypertensive nephrosclerosis; to determine if lowering blood pressure and achieving blood pressure goals considerably below the currently recommended mean arterial blood pressure (MAP) of 107 might slow the rate of decline of renal function in this patient population; to determine if Black women and men respond to blood pressure control in a similar fashion; to determine the feasibility of conducting a larger scale intervention study in this patient population; and to determine if a series of non-invasive tests can confirm the diagnosis of hypertensive renal disease. The proposed experimental design is a multi-center randomized prospective controlled double masked study. Only Black Americans with hypertensive nephrosclerosis and no other major medical illnesses will be enrolled. Following a series of screening tests which conclude with a renal biopsy, patients will be randomized to either receive CEI or CCB and other anti-hypertensives as needed to achieve either a MAP goal between 100-107 mm/Hg or equal to or less than 92 mm/Hg. Non-pharmacologic therapeutic interventions will be monitored in all patients. Patients will have monthly clinic visits with bi-monthly laboratory evaluations. Patients' renal function, the major outcome variable, will be evaluated by measuring glomerular filtration rate (GFR) (Iothalamate). Stop points include: halving initial renal function, GFR below 12 ml/min, uncontrolled blood pressure, or adverse events.
