ORLANDO, Florida – The Oscar-winning movie "Million Dollar Baby" has nothing on the competition at the annual meeting of the American College of Cardiology (Bethesda, Maryland) ongoing this week at the Orange County Convention Center.

In a battle royal between heavyweights, the Cypher drug-eluting stent (DES) from the Cordis (Miami Lakes, Florida) unit of Johnson & Johnson (New Brunswick, New Jersey) is trading clinical trial punches with the Taxus DES from Boston Scientific (Natick, Massachusetts) in studies comparing the two.

It's a competition that some have touted as helping to determine who carves out the largest piece of the multibillion-dollar DES pie. The early rounds of this slugfest, featured at initial Sunday morning presentations, appeared to produce a split decision for the Cypher stent – on "points," you might say – but these first rounds are very preliminary indeed.

Emphasizing this, Gregg Stone, MD, professor of medicine at Columbia University Medical Center (New York), an investigator not involved in the Cypher/Taxus comparisons, said that while both DES devices continue to show superiority over bare-metal stents, many more DES studies are needed and that "better and safer drug-eluting stents" are likely to enter the ring.

DES devices "do have risks," Stone said, adding that the exact nature and extent of these risks will not be known "until we implant millions and millions more and do more studies."

In the current contest, delivering the first hard punch was Adrian Kastrati, MD, of the Deutsches Herzzentrum (Munich, Germany), who reported on a study comparing the two stents in diabetic patients, concluding that the sirolimus- eluting Cypher stent is superior to the paclitaxel-eluting Taxus stent to prevent restenosis in this group of patients considered at higher risk than those without this complication. The procedure for the study was a comparison of 250 patients in each group, with an angiogram study at nine months.

Kastrati reported a greater late lumen loss – meaning a more restricted blood flow and likely increased risk of revascularization – for the Taxus as compared to the Cypher, with the result that "you would select the Cypher stent in diabetic patients."

More than once Kastrati noted the importance of the diabetic patient pool, saying that more difficult patients would tend to show larger differences, if they existed, and that "the relationship between late lumen loss and restenosis is made more evident in diabetics. If you look at our patients, it's particularly important to have less late lumen loss."

Aside from this key difference, he reported no significant differences in "navigating" stent placement and in adverse events.

Somewhat softening that blow for Boston Scientific was the presentation of the much-hyped REALITY trial data at the meeting. The study, funded by Cordis, failed to prove a benefit for the company's Cypher stent over the Taxus stent, thus missing its primary endpoint of a significant reduction in eight-month binary restenosis. Cypher produced a rate of 9.6% vs. 11.1% for Taxus.

However, in a report on the REALITY trial comparing the two stents in the treatment of "routine, de novo lesions" rather than diabetics, researchers at the Institut Jacques Cartier (Massey, France) treated 684 patients (970 lesions) with the Cypher and 669 patients (941 lesions) with the Taxus.

Marie-Claude Morice, MD, head of cardiology at the institute, reported various similarities between the two DES systems – deliverability, rates of reclogging, efficacy – but noted other study trends "in favor of" the Cypher.

The clearest difference, she said, was in-stent thrombosis. "In this study, the incidence of in-stent thrombosis was 78% lower with the Cypher stent than with the Taxus," Morice said, and that those receiving the Cypher "had a significantly larger vessel diameter inside the stent after eight months of follow-up."

While both Kastrati and Morice appeared to give most split-decision points to the Cypher, they were reluctant to say the study findings offered definitive guidance to interventionalists for choosing one stent over the other. And this is a conclusion that seems unlikely to greatly change clinical practice which has given Taxus, thus far, about 70% of the clinical use in the U.S.

As an investigator not involved in those studies, Stone again provided perspective by saying that neither of these trials had provided enough "power," in terms of the number of patients studied, to offer either robust or definitive conclusions about device superiority.

He did offer one conclusion about DES technology in general, however, from the analysis of riskier patients: "What we've learned, as you expose more and more complex lesions to [stent treatment], you are going to have patients who come back with restenosis."

Stone's own report presented at ACC was on the TAXUS V study comparing the Taxus DES against a bare-metal stent, as did TAXUS IV, and continuing to show the DES as superior.

He noted the efficacy of Taxus in "a challenging patient population with multiple, concurrent risk factors, including small vessels and long lesions requiring multiple stents, which has never before been studied with drug-eluting stents."

Stone did report "a small but elevated rate of non-Q-wave MI [myocardial infarction] in Taxus patients receiving multiple overlapping stents compared to control." But he added that this "was most likely related to reduction in side branch blood flow and balanced by the reduction in reintervention of more than 50% in the Taxus group."

While REALITY did not score the hoped-for knockout for Cordis, an independent study presented by Swiss researchers at the meeting did help the company land a nice combination – when paired with the positive results of the aforementioned 250-patient study of diabetics – with results showing a clear benefit for Cypher.

The SIRTAX study – funded with public money, not by a pharmaceutical company – was presented by Stephan Windecker, MD, from University Hospital (Bern, Switzerland).

SIRTAX showed that in slightly more than 1,000 patients, the Cypher stent significantly outperformed Taxus. In the trial, patients who received Taxus instead of Cypher were 80% more likely have a serious cardiovascular event or surgery, according to Windecker. Most of that result was caused by an increase in the number of patients who went back into surgery, not by heart attacks or deaths. Taxus patients' arteries re-narrowed more often than those on Cypher, according to the Swiss study.

The difference may be evident because the SIRTAX study took all comers, no matter how sick, while Cordis researchers selected their patients for REALITY. SIRTAX included enough very ill patients that small advantages were easier to see.

Eric Topol, chairman of cardiology at the Cleveland Clinic (Cleveland), told Forbes.com he thought the new data could "sway the decision-making of interventional cardiologists." Topol has publicly voiced concerns about safety problems with Taxus in the past.

Among the companies attempting to join the stent fray – not with a drug/device combination but what might be termed a "disappearing" stent strategy – is Biotronik (Berlin).

Raimund Erbel, MD, of the University Clinic (Essen, Germany), reported on the initial implantation of Biotronik's resorbable stent in five patients.

Early evidence indicates that the first-in-man use showed successful resorption into the body, as imaged by intravascular ultrasound.

The advantage of this absorbable stent strategy is that it is not just biocompatible but that it leaves no non-biological artifact for the body to deal with over the long term, Erbel noted.

While follow-up for six weeks in the patients was uneventful, the first patient developed "atypical" chest pain after four weeks with normal cardiac markers and stress ECG.

One company coming up short in the battle against restenosis in the early presentations at the ACC was Novoste (Norcross, Georgia), which seems already reeling and ready to be counted out.

Researchers from the University of Aachen (Aachen, Germany) reported the superiority of the Cypher stent compared to vascular brachytherapy in preventing restenosis.

The brachytherapy system used was Novoste's Beta-Cath system, which recently reported the winding down of its operations (Medical Device Daily, Feb. 24, 2005), a clear response to the strong clinical preference by interventionalists for stent technology over radiation since international and FDA approvals of the Cypher and the Taxus were secured.