Current Perspectives on the Role of Captopril Imaging in the Diagnosis of Renovascular Disease

Abstract

As the population ages, renal artery stenosis has been increasingly detected among patients with refractory hypertension and/or renal dysfunction. There is a need for a safe, simple, reliable, cost-effective method for detecting clinically significant renal artery stenoses in patients who will benefit from revascularization. The asymmetric renal response to angiotensin converting enzyme inhibition in the setting of renal artery stenosis is the basis for several diagnostic techniques that screen patients with suspected renal artery stenoses to determine functional significance. Captopril renal scintigraphy is the most widely applied, however, ACE inhibition in conjunction with ultrasound and magnetic resonance are the focus of the most recent research. This review focuses primarily on the physiologic basis, indications, techniques and utility of captopril renal scintigraphy. Newer captopril imaging methods are introduced and consideration given to practical issues such as cost and risk/benefit analysis. Keywords Captopril, renal artery, radioisotope renographyAs our population ages, renal artery stenosis has been increasingly detected among patients with refractory hypertension and/or renal dysfunction. The evaluation and management of these often high-risk, elderly atherosclerotic patients poses significant challenges: How can clinically relevant renal artery lesions be detected most safely and reliably? If the goal is to prolong life or prevent dialysis dependence, how can we predict reliably these outcomes? And, how can we best select patients for interventions, recognizing that failed interventions in this population come at significant human and financial cost (whether they fail because the intervention is inadequate or because the renal lesion was not causative)? There is clearly a need for a safe, simple, reliable, 43