Management of atherosclerotic renovascular disease after Cardiovascular Outcomes in Renal Atherosclerotic Lesions (CORAL)

Abstract

Many patients with occlusive atherosclerotic renovascular disease (ARVD) may be managed effectively with medical therapy for several years without endovascular stenting, as demonstrated by randomized, prospective trials including the Cardiovascular Outcomes in Renal Atherosclerotic Lesions (CORAL) trial, the Angioplasty and Stenting for Renal Artery Lesions (ASTRAL) trial and the Stent Placement and Blood Pressure and Lipid-Lowering for the Prevention of Progression of Renal Dysfunction Caused by Atherosclerotic Ostial Stenosis of the Renal Artery (STAR) and ASTRAL. These trials share the limitation of excluding subsets of patients with high-risk clinical presentations, including episodic pulmonary edema and rapidly progressing renal failure and hypertension. Although hemodynamically significant, ARVD can reduce renal blood flow and glomerular filtration rate; adaptive mechanisms preserve both cortical and medullary oxygenation over a wide range of vascular occlusion. Progression of ARVD to severe vascular compromise eventually produces cortical hypoxia, however, associated with active inflammatory cytokine release and cellular infiltration of the renal parenchyma. In such cases ARVD produces a loss of glomerular filtration rate that no longer is reversible simply by restoring vessel patency with technically successful renal revascularization. Each of these trials reported adverse renal functional outcomes ranging between 16 and 22% over periods of 2-5 years of follow-up. Blood pressure control and medication adjustment may become more difficult with declining renal function and may prevent the use of angiotensin receptor blocker and angiotensin-converting enzyme inhibitors. The objective of this review is to evaluate the current management of ARVD for clinical nephrologists in the context of recent randomized clinical trials and experimental research.

Keywords: angioplasty; atherosclerosis; renal artery stenosis; renovascular hypertension; stent.

FIGRUE 1:

Spectrum of RVD manifestations: advances in imaging demonstrate some degree of RVD in many clinical conditions, much of which may be of minor importance. The clinical expression of RVD ranges from raising arterial pressure to ‘high-risk’ manifestations including flash pulmonary edema and progressive kidney injury (see text).

FIGURE 2:

Management of renovascular hypertension and ischemic nephropathy: the left panel depicts primary treatment of hypertension using antihypertensive drug therapy and reduction of atherosclerotic risk. It may be argued that if renal function remains stable and excellent BP can be achieved, little is to be gained by further imaging or renal intervention, as confirmed by the results of prospective RCTs (see text). Clinical nephrologists will face the need to identify individuals at risk for high-grade RVD that advance to ‘high-risk’ presentations, for which renal revascularization can provide major benefits. RAS, renal artery stenosis.