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

Description:

The goal of the trial was to evaluate treatment with renal artery stenting compared with continued medical management in patients with renal artery stenosis and renal insufficiency.

Hypothesis:

Renal artery stenting would be more effective in preserving creatinine clearance.

Study Design

  • Randomized

Patients Screened: 185
Patients Enrolled: 140
Mean Follow Up: 2 years
Mean Patient Age: 66 years
Female: 33%

Patient Populations:

  • Renal artery stenosis >50%
  • Creatinine clearance <80 ml/min/1.73 m2

Exclusions:

  • Renal size <8 cm
  • Renal artery diameter <4 mm
  • Creatinine clearance <15 ml/min/1.73 m2
  • Diabetes with proteinuria
  • Malignant hypertension

Primary Endpoints:

  • 20% or more decrease in creatinine clearance

Secondary Endpoints:

  • Procedural complications
  • Hypertension
  • Mortality

Drug/Procedures Used:

Patients with renal artery stenosis and renal insufficiency were randomized to revascularization with stenting (n = 64) versus continued medical management (n = 76). Renal artery stenosis was defined as >50% luminal narrowing, and renal insufficiency was defined as a creatinine clearance <80 ml/min/1.73 m2. Patients could crossover from medical therapy to stent placement if necessary for refractory hypertension.

Concomitant Medications:

All patients received atorvastatin 10 mg daily regardless of lipid profile. Hypertension was treated to <140/90 mm Hg with the use of diuretics, calcium antagonists, beta-blockers, and alpha-blockers as first-line agents. All patients received aspirin 75-100 mg daily.

Principal Findings:

Overall, 140 patients were randomized. Of the 64 patients assigned to stent placement, only 46 ultimately had the procedure, mostly due to false-positive findings on noninvasive imaging. One patient in the medical group received a stent due to refractory hypertension. There was no difference in baseline characteristics between the groups. In the stent group, the mean age was 66 years, 33% were women, the mean creatinine was 1.7 mg/dl, mean systolic blood pressure was 160 mm Hg, mean number of antihypertensive drugs was 2.8, and >90% stenosis was present in 34%.

By intention to treat, the primary outcome of 20% or more decrease in creatinine clearance at 2 years occurred in 16% of the stent group versus 22% of the medical therapy group (p = NS), and by protocol analysis, 18% versus 19% (p = NS). Among those with only unilateral stenoses, the primary outcome occurred in 9% versus 20% (p = NS), and among those with only bilateral stenoses, 22% versus 23% (p = NS).

All-cause mortality was 8% versus 8% and cardiovascular mortality was 3% versus 5%, respectively. Three of the five deaths in the stent group were due to procedure-related deaths (n = 2), and one late death was due to infected hematoma (n = 1).

Interpretation:

Among patients with renal artery stenosis and renal insufficiency, a strategy of revascularization with stenting was not superior to continued medical therapy. Renal artery stenting was not able to preserve creatinine clearance at 2 years of follow-up. There was also no difference based on the presence of unilateral or bilateral stenoses, or when the results were analyzed by intention to treat or by treatment received.

All-cause mortality was similar between the groups, although stenting resulted in two procedural deaths and one late death from an infected hematoma. One limitation of this trial is that only one-third of patients had a stenosis >90%, whereas one-third had moderate stenosis (50-70%). Therefore, it remains possible that revascularization may benefit critical stenoses. In general, these findings are consistent with the ASTRAL trial. The results of the ongoing CORAL trial are eagerly awaited.

References:

Bax L, Woittiez AJ, Kouwenberg HJ, et al. Stent placement in patients with atherosclerotic renal artery stenosis and impaired renal function: a randomized trial. Ann Intern Med 2009;150:840-8.

Clinical Topics: Dyslipidemia, Invasive Cardiovascular Angiography and Intervention, Prevention, Vascular Medicine, Lipid Metabolism, Statins, Interventions and Vascular Medicine, Hypertension

Keywords: Follow-Up Studies, Diuretics, Heptanoic Acids, Constriction, Pathologic, Hematoma, Creatinine, Peripheral Vascular Diseases, Stents, Pyrroles, Renal Insufficiency, Anthozoa, Renal Artery Obstruction, Intention to Treat Analysis, Hypertension


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