Many Patients Getting DES Would Do as Well With Bare-Metal Stents: NCDR Registry

Reed Miller

July 10, 2012

July 10, 2012 (Kansas City, Missouri) — Routinely implanting bare-metal stents instead of drug-eluting stents (DES) in patients at low risk of restenosis would create significant cost savings and lead to very few additional target vessel revascularization (TVR) procedures, according to the authors of a new retrospective study from the National Cardiovascular Data Registry (NCDR)--CathPCI [1].

Dr Amit Amin (Washington University, St Louis, MO) and colleagues analyzed records from over 1.5 million PCIs in the NCDR-CathPCI registry from 2004 through 2010. Using a validated prediction model based on the Massachusetts Data Analysis Center database, they estimated the one-year risk of a patient who had received a bare-metal stent needing a TVR. Results of the study are now published online July 9, 2012 in the Archives of Internal Medicine.

Among 2175 physicians performing at least 75 stent procedures per year, there was wide variation in how often each of them chose a DES for their patients, ranging from 2% of their cases to 100% of their cases. DES were used in 73.9% of patients with less than a 10% risk of TVR within a year. DES were used in 78% of the patients with a 10% to 20% one-year TVR risk and in 83.2% of patients with at least a 20% TVR risk.

The authors calculated the costs and benefits of using DES vs bare-metal stents in each procedure with a statistical model accounting for the cost of stents, the costs of repeat revascularization, and the costs of dual antiplatelet therapy. They assumed that elective-procedure patients would be on dual antiplatelet therapy for one month if they got a bare-metal stent but stay on the therapy for one year after a drug-eluting stent. For patients getting a stent for an acute coronary syndrome, the model assumed a full year of dual antiplatelet therapy regardless of which kind of stent they received.

Based on this model, the authors concluded that if half of the low-TVR-risk patients currently receiving DES got a bare-metal stent instead, the US healthcare system would save $205 million per year while increasing the overall TVR event rate by only 0.5%. The authors state that they modeled only a 50% reduction in DES use in the low-risk group in order to describe a scenario where patients' and physicians' retain the right to exercise judgment on a case-by-case basis. "Our intention was not to advocate a sweeping policy change that would limit physician and patient autonomy but rather to illustrate the potential for cost savings, without a significant increase in patient morbidity, that could be achieved with an evidence-based approach to stent selection, and to encourage shared decision making with patients," Amin et al explain.

In an accompanying editorial [2], Dr Peter W Groeneveld (Philadelphia Veterans Affairs Medical Center, PA) writes that most interventionalists do not have any financial incentive to choose a less-expensive device even if it would be just as safe and effective for their patient as the more expensive technology. "In a 'price-free' environment, the natural inclination is to select the more expensive option."

However, "as the resources to pay for healthcare are limited, it is inevitable that medical decision making in the US will be increasingly driven by value maximization," Groeneveld predicts. "Presumably, this will be accomplished to some degree by placing local health systems (eg, accountable care organizations) and their constituent hospitals and physicians increasingly at risk for the economic consequences of their decision making."

Aligning Costs With Incentives

Dr Paul Chan (St Luke's Mid-America Heart Institute, Kansas City, MO), told heartwire that "unless there are built-in incentives that make physicians pause and think about whether or not a patient really requires a DES, whether those incentives are some kind of cost-sharing or even some kind of penalty when it is used in patients who don't need one, there's not going to be a lot of forethought on whether the patient needs a DES.

"Now, clearly there are some physicians who are thinking appropriately about whether a bare-metal stent should be used instead," Chan noted. "But we know from other disease conditions that it can be very difficult to change physician behavior unless there are financial incentives."

The study by Amin et al assumed that elective-PCI patients would be on dual antiplatelets for only one month if they got a bare-metal stent, vs a year with a DES, so those DES patients would be at a higher risk of bleeding, Chan pointed out. "I think that if these patients were really provided fully informed consent knowing, going into the procedure, that they're at low risk . . . compared with a higher risk of bleeding and a higher cost, a good number of patients would probably opt to forgo DES," Chan said. However, patients' decisions on this trade-off haven't been well-studied, he said. "Some of the times, physicians make decisions based on what they perceive patients want them to do, which is to provide the most expensive care or to avoid the clinical complication of TVR; [however,] they don't view a bleeding event as a patient complication per se but as an inconvenient problem."

Chan, who has written extensively on appropriate-use criteria, acknowledged that Amin trained at his center in Kansas City and that several of the study coauthors currently work at St Luke's Mid-America Heart Institute.

In a conversation with heartwire ,Dr Jeffrey Marshall (Northeast Georgia Heart Center, Gainesville), president of the Society for Cardiovascular Angiography and Interventions (SCAI), pointed out that several previous studies--including some by one of the coauthors of the Amin et al study, Dr David J Cohen (University of Missouri, Kansas City)--"clearly show that DES are cost-effective and save money in the long run."

He also pointed out that the study assumes that elective bare-metal-stent patients will be on dual antiplatelet therapy for only one month, even though the most current American Heart Association/American College of Cardiology guidelines statethat "ideally" both bare-metal-stent and DES patients should be on dual antiplatelet therapy for one year. "Part of the cost analysis should include [that dual antiplatelet therapy], so that's a bit of a flaw [in the study], and it's also pretty obvious from the data that DES are much better in patients with STEMI and ACS in randomized trials," Marshall said. He added that the number of revascularization procedures in the US are down overall in the past five years, and "some of that is certainly due to the marked reduction in restenosis that clinicians are seeing [with DES].

"This is a good study for generating hypotheses but not for making these hard conclusions," Marshall said of the Amin et al study. "This is not something that we can generate practice models from."

Amin and Groeneveld list no disclosures. Chan has received support from a career development grant award from the National Heart, Lung, and Blood Institute to examine the appropriateness of PCI in the US. Marshall reports grant research support from Corindus, Abbott, Medtronic, Lilly, Daiichi-Sankyo, Schering-Plough, Sanofi, St Jude, and Boston Scientific. He serves on an advisory board/speaker's bureau for the American Board of Internal Medicine and Abbott.

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