Captopril test in the detection of renovascular hypertension in a population with low prevalence of the disease. A prospective study.

The value of the captopril test as a screening test for identifying renovascular hypertension has been outlined by several studies performed in populations with a high prevalence of renovascular disease (20% to 50%). We prospectively assessed the value of the test in 103 hypertensive patients referred to our center for evaluation of their hypertension. They had taken no diuretics and no converting-enzyme inhibitors for more than four days. The interpretation of the results of the test was done according to the criteria defined by Muller et al. All patients underwent a digital venous angiography and when positive or doubtful, a conventional angiography. Eleven patients (10%) had unilateral or bilateral artery stenosis greater than 70%. The sensitivity of the test was 73% with a specificity of 84% and a positive predictive value of 35%. The three patients with a false negative test underwent a surgical treatment or a transluminal angioplasty of the stenosis but remained hypertensive. Thus, the captopril test is a useful screening test for identifying patients with renovascular disease, even in a population with a low prevalence of the disease.