HDCN Article Review/Hyperlink

Emovon OE, Klotman PE, Dunnick R, Kadir S, Svetkey LP

Renovascular hypertension in blacks

Am J Hypert (Jan) 9:18-23 1996

In unselected series, renovascular hypertension (RVH) is thought to be extremely rare (less than 1%) in African Americans. However, when 79 black patients were selected for severe or refractory hypertension, Emovon et al found that 14 (18%) had renal artery stenosis (RAS) on angiography, of which half fulfilled diagnostic criteria for renovascular hypertension (RVH, response after balloon dilatation). More than half (43/79) with RAS had an abdominal bruit. Otherwise there were few clinical clues to either RAS or RVH. Baseline and captopril stimulated peripheral vein renin levels were useless, and were far less sensitive and specific at this center even in white patients. Captopril renography was done by comparing right vs. left GFR after 25 mg captopril. A greater than 6% difference was considered positive. Sensitivity of captopril renography for RAS in blacks was 64% with a specificity of 58%, versus 78% and 83% in similarly selected white patients.

Comment: The study suggests that in black patients with severe or refractory hypertension, particularly with onset before age 25 or after age 45, renal artery stenosis occurs not infrequently, and that failure to work such patients up for RVH will deny such patients the potential benefits of angioplasty or corrective surgery. (John T. Daugirdas MD, University of Illinois at Chicago)