Heart Disease :: Stent wars ease into stent discussions

Acrimonious debate over the use of bare metal stents (BMS) versus drug-eluting stents (DES) is ending. Four new studies presented during a Monday news conference are quickly turning what had been open warfare between BMS and DES advocates into more measured discussions.

?We no longer have a war on our hands but a very serious discussion about which direction to take,? said AHA Past-President Sidney Smith Jr., M.D., professor of medicine and director of the Center for Cardiovascular Science and Medicine at the University of North Carolina at Chapel Hill.

Early data had suggested that DES produce clearly superior clinical results, Dr. Smith noted. Longer-term studies suggest that by three years after stenting, there are few significant differences in outcomes between the two types of devices. Use of DES is widespread.

Patients with DES sicker
Data from Rhode Island Hospital suggest caution when using DES. The question is not about the safety or the efficacy of DES, but about patient selection. Analysis of early clinical practice revealed that DES patients tend to be sicker than patients fitted with BMS, explained David Williams, M.D., director of the hospital?s Cardiovascular Laboratory and Interventional Cardiology and a professor of medicine at Brown University Medical School, Providence, R.I.

An analysis of more than 3,000 patients from the National Heart, Lung, and Blood Institute Dynamic Registry showed that DES patients had more cardiovascular risk factors, more prior revascularization and longer, more complex lesions than BMS patients. Despite the increased risks, DES patients had similar rates of in-hospital deaths and subsequent myocardial infarct during the year following stent implantation.

?In these toxic events, we saw no difference between the two groups,? Dr. Williams said.

In therapeutic terms, DES patients required about 50 percent fewer repeat revascularizations or bypass grafts, 10.1 percent compared to 15 percent for BMS patients.

DES patients more likely to die after three years
The picture is less clear after three years. Joseph B. Muhlestein, M.D., found that patients fitted with DES had higher all-cause mortality than patients fitted with BMS. ?This was an unexpected finding. We believe that more aggressive disease was treated in the DES group, probably due to the more aggressive reputation of DES,? said Dr. Muhlestein, director of cardiology research at Intermountain Healthcare and LDS Hospital, director of the LDS Hospital/University of Utah Interventional Cardiology Training Program and a professor of medicine at the University of Utah, Salt Lake City.

The Intermountain Heart Study followed 9,043 patients given either BMS (7,022) or DES (1,949) between 1993 and 2005. While the incidence of MI, target vessel revascularization (TVR) and coronary bypass surgery was lower for DES patients, the hazard ratio for death from any cause was 2.15, and the hazard ratio for major adverse cardiac event was 2.28 for the DES group. The risk of TVR was reduced in the DES group, but DES roughly doubled the risk of revascularization of any vessel.

?We may be taking on sicker patients with DES than we did in the past,? Dr. Muhlestein said. ?Given the dominance of DES, we need to exercise more caution and we need more long-range scrutiny.?

Two other studies may affect the use of DES.
Dutch researchers found that repeat vascularization rates are similar in patients who suffered an ST-segment elevation myocardial infarction (STEMI) for sirolimus-eluting stents and paclitaxel-eluting stents.

Analysis of major registry data found that DES now accounts for about 96 percent of all stents, but that use of DES is not uniform. Patients with private insurance are most likely to be given DES, followed by patients in government health plans. Patients with no health insurance were least likely to be given DES.

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