ASTRALogy: Unrealistic Expectations?

Awell-recognized cause of secondary hypertension is renal artery stenosis (RAS), but uncertainty exists regarding whether it is worthwhile to actively search for this condition. First, the diagnosis of RAS requires either an invasive procedure (digital subtraction angiography [DSA]) or a noninvasive yet costly investigation such as magnetic resonance angiography (MRA) or CT angiography (CTA). One shared disadvantage of the latter two methods is that it is necessary to administer contrast material to the patient. Second, it is not so easy to select for further study those patients in whom a reasonable chance of finding a stenotic lesion exists. Finally, an effective treatment must be available in order to justify screening for RAS. Thus, starting a diagnostic strategy for RAS in a hypertensive patient makes sense only if one is prepared to take the consequences of the outcome and perform angioplasty with or without stent placement when a stenosis is considered to be hemodynamically significant. Precisely the last point is subject to debate. There are few data from randomized trials on the results of percutaneous transluminal renal angioplasty (PTRA) as compared with medical treatment in hypertensive patients with RAS. These studies were small and the results were equivocal. With respect to angioplasty plus stenting, even less information is at hand. Therefore, the Angioplasty and Stenting for Renal Artery Lesions (ASTRAL) trial was designed to explore whether angioplasty and stenting together with medical treatment would improve renal function more than medical treatment alone in patients with atherosclerotic RAS.