AHA: DES = BMS for large coronary arteries, but not conclusively

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Xience V drug-eluting stent
Image source: Abbott Vascular

CHICAGO—In patients requiring stenting of coronary arteries larger than 3 mm in diameter, no significant differences were found among sirolimus-eluting, everolimus-eluting and bare-metal stents with respect to the rate of death or MI, according to the late-breaking BASKET-PROVE trial, which was presented today at the American Heart Association (AHA) Scientific Sessions. However, the trial was technically underpowered.

The original BASKET long-term outcomes suggested that patients with large native vessel stenting were at increased risk of late stent thrombosis and related cardiac death and MI after first-generation drug-eluting stent (DES) implantation compared with bare-metal stents (BMS) (Lancet 2005;366:921-929).

As a result, the BASKET-PROVE trial researchers sought to prove or refute the hypothesis that compared with BMS, first-generation DES provide only a small reduction in target vessel revascularization (TVR) and may increase late cardiac death and MI. They also sought to evaluate whether a similar risk-benefit balance  would be found for second-generation DES, reported study investigator Christoph A. Kaiser, MD, head of interventional cardiology at University Hospital Basel in Switzerland, who presented the study at this morning’s press conference.

In this multicenter trial, the researchers enrolled 2,314 patients at 11 centers in Switzerland, Denmark, Austria and Italy, dividing them into three stent groups: sirolimus-eluting (Cypher Select, Cordis), everolimus-eluting (Xience V, Abbott) and bare-metal (Vision, Abbott).

The rates of TVR—for reasons unrelated to MI—were 3.7 percent among patients receiving sirolimus-eluting stents, 3.1 percent among those receiving everolimus-eluting stents, and 8.9 percent among those receiving BMS. “The rate of TVR was significantly reduced among patients receiving either DES, as compared with a BMS, with no significant difference between the two types of DES,” the study authors reported in the New England Journal of Medicine, where the study was simultaneously published.

After two years, the rate of cardiac death or heart attack was 2.7 percent for the sirolimus-eluting stents, 3.3 percent for the everolimus-eluting stents and 4.8 percent for the BMS.

“For small vessels, DES are already the implant of choice,” said Kaiser. “Now that DES show no harm in large vessels, I think doctors will change to bolster use of DES in large arteries.”

However, due to “unexpectedly low event rates,” the trial was underpowered to detect small differences in events, the researchers acknowledged. In their hypothesis, the investigators predicted an event rate of 6 percent for cardiac death and MI in the BMS arm and 10.5 percent in the DES arms.

“Because the actual event rate was much lower—20 percent lower in the BMS arm and more than 70 percent lower than expected in the DES arm—it leads to the observation that the study is technically underpowered,” explained Marco K. Valgimigli, MD, PhD, from the University of Ferrera in Italy, who was the study’s discussant at this morning’s press conference. “Therefore, BASKET-PROVE is not conclusive, because it cannot rule out the existence of a smaller than anticipated difference in events.”

Yet, Valgimigli added that the BASKET-PROVE results are “highly reassuring,” especially with regards to the safety data for DES.

Despite Valgimigli’s cautions, Kaiser concluded that there is “no late harm for DES in patients with large vessels. The fear of using DES in large vessels is no longer justified.”

The Basel Cardiovascular Research Foundation and the Swiss National Foundation for Research supported the study, and the researchers reported that they received no industry sponsorship.