This article is reprinted from "The Gray Sheet" – November 26, 2007
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CMS' proposal to maintain its existing renal stenting coverage policy surprises many stakeholders who expected the agency to further restrict coverage because the data on the intervention's effectiveness is relatively weak.
The agency strongly encourages enrollment in randomized clinical trials to resolve "general uncertainty" about whether stenting offers any benefits or risks over other treatment options, but it stops short of making trial enrollment a condition of coverage in the Nov. 20 1proposed coverage policy.
For at least the past decade, percutaneous transluminal angioplasty of the renal arteries has been nationally covered as an alternative to surgery in patients who have not responded to drug therapy. Coverage of renal artery stenting is at the discretion of local Medicare contractors.
In response to the rapid growth of the procedure, in 2006, CMS asked the Agency for Healthcare Research and Quality to conduct a comparative evidence review of renal artery disease treatments, including drug management and intervention. AHRQ found that available evidence, which was generally weak and outdated, did not support one treatment over the other.
"Absent any reported additional serious patient harms, further national coverage reconsideration of renal artery revascularization procedures will ethically and scientifically depend upon peer-reviewed publication and critical evaluation of convincing new RCT evidence," CMS' coverage proposal states.
The agency nonetheless acknowledges that there is little incentive under the current coverage policy for investigators to conduct rigorous trials for renal intervention.
The National Institutes of Health-sponsored CORAL trial, for example, randomizing patients to renal stenting with drug therapy or drug therapy alone, has enrolled very slowly. Investigators partially blame the slow enrollment on the coverage policy (2"The Gray Sheet" June 18, 2007, p. 5).
CMS convened the Medicare Evidence Development and Coverage Advisory Panel for feedback on whether coverage should be limited to clinical studies in July. Experts on the panel stressed the need for better data (3"The Gray Sheet" July 23, 2007, p. 18).
To date, coverage-with-evidence-development decisions have generally required patient enrollment in registries, but CMS notes that a registry in this case would not provide adequate clinical oversight. Because most renal stenting procedures are performed off-label, CMS is concerned about patient protection.
Two stents were approved for a renal indication in 2002 (Cordis' Palmaz and Medtronic's Bridge) but neither are currently on the market. Almost all clinicians use off-label biliary stents, which go through the less rigorous 510(k) clearance process, CMS notes.
Manufacturers of biliary stents include Johnson & Johnson/Cordis, Boston Scientific, Medtronic, ev3, Abbott, Cook, Edwards Lifesciences and CR Bard.
Comments on CMS' coverage proposal are due Dec. 20 with a final decision expected in February.
- Chloe Taft
