In addition, Dr Teguh Santoso (University of Indonesia Medical School, Jakarta), who presented the real-world results from the Medistra Excel Drug-Eluting Stent Trial (MEDISTRA) registry here at the TCT 2006 meeting, showed that treatment with the bioabsorbable polymer-based sirolimus-eluting stent, known as Excel, resulted in significantly less in-segment and in-stent late loss, as well as significantly less in-segment and in-stent restenosis, when compared with first-generation drug-eluting stents and bare-metal stents.

"Despite the inclusion of challenging real-world cases, like type 2 diabetes mellitus, multivessel disease, small vessels, complex lesions, long and diffuse disease, calcified stenosis, and others, these preliminary Excel results are encouraging, with very low MACE rates and a 'clean' angiographic appearance of the stent," Santoso said during a media briefing announcing the results.

The MEDISTRA trial was a single-center, prospective, observational study that included "all-comers" undergoing PCI. Of the 277 patients undergoing treatment, approximately half presented with stable angina, while just over 10% presented with unstable angina or acute coronary syndrome. Another 10% had either an acute MI or MI within the last 30 days. More than half the patients had hypertension or dyslipidemia, and 40% had diabetes mellitus.

The trial, which was not sponsored by industry, was designed to assess the rates of TVR/TLR at six and 12 months in patients treated with the Excel stent. Secondary end points included six-month in-segment restenosis rates and in-segment late loss. Investigators were encouraged to use the Excel stent, but if the appropriate size or length was not available, other drug-eluting stents—including Cypher, Taxus, and Endeavor—or a bare-metal stent could be used. Overall, 771 stents were implanted, of which 470 were the Excel stent. Of the rest, 137 sirolimus-eluting, 66 paclitaxel-eluting, and 46 bare-metal stents were implanted in patients.

In-hospital outcomes were positive, with no reported deaths or adverse events. At 30 days, there were two reported cardiac deaths, one case of TVR/TLR, and two cases of subacute thrombosis. Of the patients who died, Santoso said that one had diffuse disease with small vessels, as well as an overlap of the Cypher and Excel stents. The other patient was similar, with diffuse, small-vessel disease, but had five stents implanted. At six months and 12 months, there were no additional deaths, but there were three more cases of TVR/TLR by six months and another two cases at 12 months. There was no late stent thrombosis, reported Santoso.

In angiographic follow-up in 94 patients at six months, investigators report that in-segment and in-stent late loss was minimal, just 0.01 mm and 0.07 mm, respectively, in the Excel-treated patients, much less than that observed with the Cypher, Taxus, and bare-metal stents. In-segment and in-stent restenosis rates were also low, said Santoso, approximately half of what was seen with the other stents.

With this drug, after six months the polymer disappears, and the stent behaves like a bare-metal stent.

Interestingly, the stent, made by JW Medical Systems Ltd, is priced around US $1200, much cheaper than other drug-eluting stents on the market. According to Santoso, the technology is not inferior to other products, but the fact that it is made in China allows the company to keep the price low, making it an attractive alternative to clinicians looking for the bang of drug-eluting stent without having to pay the big bucks.

"The stent is much cheaper, but we know that the platform is very good, and we know that the drug is also very good," said Santoso. "The polymer is also very good, this biodegradable polymer, so we are very confident."

With the issue of late stent thrombosis one of the major themes running through TCT 2006, with countless program hours devoted to the issue, Santoso believes that the stent, with its disappearing polymer, might offer advantages over other stents currently approved. "There are various causes [of late stent thrombosis], but at the moment, one of the causes we believe is the polymer. With this drug, after six months the polymer disappears, and the stent behaves like a bare-metal stent. This is, theoretically, one of the reasons why the stent might be safer."

Dr Philip Urban (Latour Hospital, Geneva, Switzerland), who commented on the study during the late-breaking clinical-trials session, called the device "promising" and said that the data compare well with Cypher, the other sirolimus-eluting stent. He pointed out, however, that a number of patients were lost during follow-up, with only 75% of patients available for clinical follow-up at six months and 50% available at 12 months. Also, angiographic follow-up was available in only 34% of patients at six months.

"Of course, this quite markedly affects what degree of confidence we can have with the results," said Urban.

The late-loss findings, however, are excellent, said Urban, but he cautioned against comparisons with the other stents in this registry, as the study was nonrandomized, in addition to having limited follow-up data on patients. In addition, although there was no late stent thrombosis, Urban said little should be made of this finding until more data become available in future trials.

"What can we say today from these data?" asked Urban. "It's very encouraging, but it's preliminary. It's consecutive patients from a single center. . . . Efficacy seems to be good, but the follow-up limits the value we can give to those data." Further, longer-term follow-up, with adjudication of events, as well as a randomized comparison with the other drug-eluting stents, will be necessary to learn where this new stent could fit into the existing armamentarium, he said.