Cardiac events in hypertensive patients with renal artery stenosis treated with renal angioplasty or drug therapy: meta-analysis of randomized trials

Atherosclerotic renal artery stenosis and revascularization

Atherosclerotic renovascular disease is the most common cause of secondary hypertension. The patients with renovascular disease are at increased risk for adverse cardiac outcomes. Recent trials comparing medical therapy alone to medical therapy with stenting are flawed, but lay to rest any existing debate that unselected revascularization is unwarranted; however, revascularization may be appropriate in high-risk populations. Defining an appropriate population for revascularization is an area of ongoing study. Furthermore, delivery of optimal medical therapy in this population is inadequate. This review describes recent developments in renal artery revascularization.

Meta-analysis of revascularization versus medical therapy for atherosclerotic renal artery stenosis

The aim of the study was to compare the efficacy of revascularization versus medical therapy in patients with atherosclerotic renal artery stenosis (ARAS). ARAS is the most common cause of secondary hypertension and is associated with several complications, such as renal failure, coronary artery disease, cardiac destabilization, and stroke. Medical therapy is the cornerstone for management of ARAS; however, numerous trials have compared medical therapy with revascularization in the form of percutaneous renal artery angioplasty (PTRA) or percutaneous renal artery angioplasty with stent placement (PTRAS). Medline (PubMed and Ovid SP), Embase, Cochrane Central Register of Controlled Clinical Trials (CENTRAL), and Cochrane Database of Systematic Review (CDSR) were searched till present (November 2013) to identify clinical trials where medical therapy was compared with revascularization (PTRA or PTRAS). We performed a meta-analysis using a random effects model. The heterogeneity was assessed using I2 values. The initial database search identified 540 studies and 7 randomized controlled trials, and 2,139 patients were included in the final analysis. Angioplasty with or without stenting was not superior to medical therapy with respect to any outcome. The incidence of nonfatal myocardial infarction was 6.74% in both the stenting and medical therapy group (odds ratio=0.998, 95% confidence interval 0.698 to 1.427, p=0.992), and incidence of renal events in stenting population was found to be 19.58% versus 20.53% in medical therapy (odds ratio=0.945, 95% confidence interval 0.755 to 1.182, p=0.620). In conclusion, PTRA or PTRAS does not improve outcomes compared with medical therapy in patients with ARAS. Future studies should investigate to identify patient subgroups that may benefit from such an intervention.

Renal angioplasty for atherosclerotic renal artery stenosis: Cardiologist's perspective

Atherosclerotic renal artery stenosis (ARAS) is frequently associated with concomitant coronary and peripheral arterial disease with a significant impact on cardiovascular morbidity and mortality. Renal angioplasty of ARAS is more challenging because of increased incidence of technical failures, complications, and restenosis; while there is barely perceptible control of hypertension and only marginal improvement in renal function. This is because most of the patient population in recent randomized trials had unmanifested or clinically silent renovascular disease. Manifestations of RAS should be looked for and incorporated in the management plan particularly before deciding for revascularization. In the absence of clinical manifestation like renovascular hypertension, ischemic nephropathy, left ventricular failure, or unstable coronary syndromes; mere presence of RAS is analogous to presence of concomitant peripheral arterial disease which increases risk of adverse coronary events. Dormant-RAS in the absence of any manifestations can be managed with masterly inactivity. Chronological sequence of events and clinical condition of the patient help in decision making by identifying progressive renovascular disease. Selecting patients for renal artery stenting who actually will benefit from revascularization shall also decrease the unnecessary complications inherent with any interventional procedure. The present review is an attempt to analyze the current view on the diagnostic and management issues more specifically about the need and rationale behind angioplasty.