Diagnosing Renovascular Hypertension

Abstract

Diagnosing renovascular hypertension is important because treating renal artery stenosis may cure the patient's hypertension. Atherosclerosis accounts for 60% of patients with renal artery stenosis, followed by fibromuscular dysplasia in 35%. A small number of patients have renovascular hypertension because of other forms of vasculitis. 1 Renovascular hypertension is found more commonly in caucasians than it is in other ethnic groups, and, surprisingly, diabetic patients who are also hypertensive are less likely to suffer from renovascular hypertension than are their nondiabetic counterparts. 1 Atherosclerotic renal artery stenosis is a progressive disease. If left untreated, renal artery stenosis progresses at approximately 8 to 12% per year. 2,3 Prospective studies using duplex Doppler ultrasound have demonstrated that 23% of patients with less than 60% ABSTRACT Diagnosing renovascular hypertension is complex. Definitive diagnosis can only be made in retrospect, when a hypertensive patient with renal artery stenosis improves following correction of the stenotic arterial lesion. Screening for renovascular hypertension in all hypertensive patients is impractical because of the low prevalence of the disease. However, the diagnosis is important because treatment can lead to potential cure. A select group of patients with clinical signs and symptoms suggesting renovascular hypertension need to be investigated further for the cause of their hypertension. A number of clinical tests help in screening patients that require further imaging tests. The tests designed for evaluating renovascular hypertension assess the functional and anatomic abnormalities. This article reviews various clinical and imaging techniques available for evaluating these patients. A description of each technique is followed by a discussion of its advantages and disadvantages. The authors also propose an algorithm for work-up of patients with a high probability of renovascular hypertension.Objectives: After reading this article, the reader will understand the pathophysiology of renovascular hypertension and the indications for screening tests for the disease, and be able to develop an algorithm for the diagnostic evaluation of patients suspected of having renovascular hypertension. Accreditation: Tufts University School of Medicine is accredited by the Accreditation Council for Continuing Medical Education to sponsor continuing medical education for physicians. TUSM takes full responsibility for the content, quality, and scientific integrity of this continuing education activity. Credit: The Tufts University School of Medicine designates this educational activity for a maximum of 1.0 hours credit toward the AMA Physicians Recognition Award in category one. Each physician should claim only those hours that he/she actually spent in the educational activity.