The captopril tests: a new concept in detecting renovascular hypertension?

An undetermined percentage of the 60 million hypertensive Americans have potentially correctable renovascular hypertension (RVHT). Conventional plasma renin activity (PRA) determinations and radionuclide renography have limited sensitivity and specificity as screening tests for RVHT. Angiotensin-converting enzyme inhibition with captopril stimulates renin secretion and causes transient decreases in glomerular filtration rate and effective renal plasma flow within the stenotic kidney. Review of recent studies in hypertensive patients suggests that captopril stimulation of both PRA determinations and conventional renography may enhance the sensitivity and specificity of these studies in detecting RVHT.