Management of renal artery stenosis: the case for intervention, defending current guidelines, and screening (drive-by) renal angiography at the time of catheterization

Treatment of hypertension in patients with atherosclerotic renal artery stenosis, updated

Atherosclerotic renal artery stenosis (ARAS) is a fairly common disease of elderly patients and is discovered incidentally in 6.3% to 38% in those undergoing diagnostic cardiac or abdominal angiography. Of those patients diagnosed with renal artery stenosis, in 90% it is due to ARAS and in 10% to fibromuscular dysplasia (FMD), which is a disease of younger persons, mostly females. Renal artery stenosis is frequently associated with hypertension and impaired renal function, and it is perceived by many physicians as the primary cause of hypertension and renal failure. For this reason, they believe that hypertension and renal failure can be significantly improved by performing percutaneous transluminal renal angioplasty (PTRA) with a stent placement as the preferred treatment instead of medical therapy. This practice has led to an increase in angioplasties, especially by interventional cardiologists who are familiar with the procedure. However, the results of several randomized studies comparing interventional therapy with medical therapy have shown no significant difference between the 2 treatment modalities in blood pressure reduction and prevention and in worsening of renal function. Similar results have been found by nonrandomized trials in patients treated selectively with PTRA. For this review, a Medline search was conducted of the English-language literature from January 1, 2006 to December 31, 2013, using the terms atherosclerotic renal artery stenosis and renal artery stenosis; 6 pertinent randomized studies were selected. These studies, with collateral literature, are discussed in this review. The data show that PTRA with stent plus medical therapy in patients with ARAS is not superior to medical therapy alone in lowering the blood pressure, in preventing renal function deterioration, and in reducing all-cause mortality, cardiovascular morbidity or mortality, and strokes.

The current status of angioplasty of atherosclerotic renal artery stenosis for the treatment of hypertension

Atherosclerotic renal artery stenosis, a fairly common disease of older persons, is a manifestation of generalized atherosclerosis, and is often associated with coronary artery disease. It is frequently associated with hypertension and impaired renal function, and is perceived by many physicians to be the cause of hypertension and renal failure. For this reason, they believe that hypertension can be cured by performing percutaneous renal artery angioplasty (PTRA) with stent placement. This practice has led to an increase in angioplasties, especially by interventional cardiologists, although the results from several randomized studies comparing interventional therapy with medical therapy have shown no significant difference between the two treatment modalities in blood pressure reduction or change in renal function. Similar results have been found by nonrandomized trials with selective PTRA. For this review, a Medline search of the English literature was conducted from 2006 to 2012, and 13 pertinent studies were selected. These studies with collateral literature will be discussed in this concise review.

Nefropatia isquêmica

A doença renal isquêmica ou nefropatia isquêmica relacionada à doença renovascular pode evoluir de forma rápida e progressiva para a insuficiência renal crônica. É fundamental a identificação e o tratamento precoces desta condição clínica, prevenindo a ocorrência de doença renal em estágio terminal, com consequente necessidade de terapia de substituição renal. Há uma década, o controle da hipertensão renovascular era o objetivo primário no manejo de pacientes com doença renovascular. Atualmente, a meta está dirigida principalmente para a estabilização e a melhora da função renal, além do controle dos níveis pressóricos.

Renovascular hypertension and ischemic nephropathy

Renovascular disease remains among the most prevalent and important causes of secondary hypertension and renal dysfunction. Many lesions reduce perfusion pressure including fibromuscular diseases and renal infarction, but most are caused by atherosclerotic disease. Epidemiologic studies establish a strong association between atherosclerotic renal-artery stenosis (ARAS) and cardiovascular risk. Hypertension develops in patients with renovascular disease from a complex set of pressor signals, including activation of the renin-angiotensin system (RAS), recruitment of oxidative stress pathways, and sympathoadrenergic activation. Although the kidney maintains function over a broad range of autoregulation, sustained reduction in renal perfusion leads to disturbed microvascular function, vascular rarefaction, and ultimately development of interstitial fibrosis. Advances in antihypertensive drug therapy and intensive risk factor management including smoking cessation and statin therapy can provide excellent blood pressure control for many individuals. Despite extensive observational experience with renal revascularization in patients with renovascular hypertension, recent prospective randomized trials fail to establish compelling benefits either with endovascular stents or with surgery when added to effective medical therapy. These trials are limited and exclude many patients most likely to benefit from revascularization. Meaningful recovery of kidney function after revascularization is limited once fibrosis is established. Recent experimental studies indicate that mechanisms allowing repair and regeneration of parenchymal kidney tissue may lead to improved outcomes in the future. Until additional staging tools become available, clinicians will be forced to individualize therapy carefully to optimize the potential benefits regarding both blood pressure and renal function for such patients.