Medical and Endovascular Treatment of Atherosclerotic Renal Artery Stenosis (METRAS Study)

• Status: Unknown status
• Trial end date: 2016-03-01
• Target enrollment: 0
• Participant gender: All

Summary

Renal atherosclerotic stenosis (RAS) is a prevalent cause of secondary hypertension (HT). Since there are still uncertainties as to whether and in what patients revascularization by means of percutaneous renal angioplasty (PTRAS) should be pursued, we designed a study exploiting an optimized patient selection strategy and using hard experimental endpoints to unravel these uncertainties.

Primary objective: to determine if revascularization by means of PTRAS is superior or equivalent to optimal medical treatment for preserving glomerular filtration rate in the ischemic kidney as assessed by 99mTcDTPA sequential renal scintiscan.

Secondary objectives: to determine if the two treatments are equivalent in lowering blood pressure (BP), preserving overall renal function and regressing damage in the target organs of hypertension.

Design: prospective multicenter randomized, unblinded two-arm study.

Eligible patients will have clinical and/or radiological evidence of unilateral or bilateral RAS, defined by stenosis of the proximal portion of the renal artery and its main bifurcations at angioCT. Duplex scan will exclude nephroangiosclerosis as the latter could bias the assessment of the outcome of revascularization.

Inclusion criteria. RAS affecting the main renal artery or its major branches at angio-CT either > 70% or, if < 70 with post-stenotic dilatation.

Renal function will be assessed with 99mTc-DTPA renal scintigraphy.

Sample size (30 patients per arm) was calculated to have a 90% power to detect a difference in means of GFR in the vascularized (or control untreated kidney) of 7.5 ml/min.

Arms

1. Revascularization: digital scan angiography and PTA with stenting of the renal artery at the ostium or at truncular level, plus optimal medical therapy.

2. Medical therapy: the drug regimen that had been optimized during the run-in period.

Experimental endpoints:

The absolute value of GFR assessed by 99TcDTPA in the ischemic kidney will be used as quantitative variable and compared between groups at each time point. A categorical definition of kidney loss, defined as a GFR in the ischemic kidney of < 5 ml/min, will be also used and the rate of achievement of such endpoint will be compared.

Duration: 5 years.

• Phase: Phase 4
• Accepts Healthy Volunteers?: No

Details

• Lead Sponsor: University Hospital Padova

Criteria

Inclusion Criteria:

• RAS affecting the main renal artery or its major branches at angio-CT either > 70% or, if < 70 with post-stenotic dilatation AND

• resistance index (RI) < 0.55 or > 0.55 but < 0.80 with evidence of intrarenal heterogeneity of the RI as revealed by a CV > 10% in the RI across the upper, mid and lower third of each kidney.

Exclusion Criteria:

• refusal to participate to study,

• previous endovascular or surgical treatment of RAS,

• fibromuscular RAS,

• planned or actual pregnancy, or childbearing potential without measures adequate to prevent pregnancy,

• life expectancy < 2 years,

• patient currently participating in another trial possibly influencing the safety of the patient and/or the outcomes of the study,

• co-morbid conditions limiting participation and follow-up.