A type of coronary artery stent that releases a medication appears to result in better outcomes than traditional stents for heart attack patients, according to a study in the May 4 issue of JAMA.
Sirolimus, a substance that is thought to help prevent reclosure of coronary arteries, can be released from certain types of stents (metal devices inserted to keep a coronary artery open after angioplasty) to greatly reduce the need for target-vessel revascularization (TVR) compared with bare-metal stents (i.e., stents without medication), according to background information in the article. These drug-eluting stents have the potential to further improve long-term clinical outcome after primary percutaneous coronary intervention (PCI), such as angioplasty. However, the lack of randomized trials to assess the safety and long-term efficacy of sirolimus-eluting stent implantation in patients with acute ST-segment elevation (a certain measurement on an electrocardiogram) myocardial infarction (STEMI), in conjunction with the expected financial consequences, currently limit use of sirolimus-eluting stents in this setting. Current clinical guidelines specifically recommend the drug abciximab during primary PCI. At current European list prices, the use of the drug tirofiban instead of abciximab would absorb the difference in cost between stenting with sirolimus-eluting vs. bare-metal stents.
Marco Valgimigli, M.D., of the University of Ferrara, Italy and colleagues compared angiographic and clinical outcomes for the treatments of high-dose tirofiban plus sirolimus-eluting stenting vs. a current preferred strategy for STEMI treatment, pretreatment with abciximab plus bare-metal stenting. The STRATEGY trial included 175 patients presenting to a single referral center in Italy with STEMI or presumed new left bundle-branch block between March 6, 2003 and April 23, 2004. Patients received either tirofiban regimen plus sirolimus-eluting stenting (n = 87) or abciximab plus bare-metal stenting (n = 88).
The researchers found that 14 of 74 patients (19 percent) in the tirofiban plus sirolimus-eluting stent group and 37 of 74 patients (50 percent) in the abciximab plus bare-metal stent group reached the primary end point (death, nonfatal heart attack, stroke, or binary restenosis [narrowing of artery] at 8 months). The cumulative incidence of death, reinfarction, stroke, or TVR was significantly lower in the tirofiban plus sirolimus-eluting stent group (18 percent) vs. the abciximab plus bare-metal stent group (32 percent), predominantly reflecting a reduction in the need for TVR. Binary restenosis was present in 6 of 67 (9 percent) and 24 of 66 (36 percent) patients in the tirofiban plus sirolimus-eluting stent and abciximab plus bare-metal stent groups, respectively.
"In conclusion, our study provides proof of concept for a new treatment strategy in STEMI that incorporates unrestricted use of sirolimus-eluting stenting but results in no (European market) or only a modest (U.S. market) increase in medical expenditure," the authors write.