NEW ORLEANS – Acute myocardial infarction patients treated with a drug-eluting coronary stent during a primary percutaneous coronary intervention had significantly better 5-year survival, compared with myocardial infarction patients who received a bare-metal stent, in a review of more than 12,000 patients treated in New Jersey during 2003-2004.
Although this analysis could not take into account selection biases that might have determined whether patients received drug-eluting or bare-metal stents, the findings in general provide reassurance about the safety of drug-eluting coronary stents for patients with an acute MI, Dr. Tudor D. Vagaonescu said at the annual meeting of the American College of Cardiology.
"These data are consistent with the idea that using drug-eluting stents in the setting of an acute MI is safe," said Dr. Vagaonescu, a cardiologist at the Robert Wood Johnson Medical School, New Brunswick, N.J.
"Our data show that preventing the need for revascularization [by using drug-eluting stents] helped with survival, although improved survival was likely due to a combination of things, including selection bias and the type of index event," he said in an interview.
But one expert who heard the findings remained unconvinced that drug-eluting coronary stents, especially the first-generation models (sirolimus- or paclitaxel-eluting) used during the era that the registry covered, have an advantage over bare-metal stents.
"These data don’t argue for using drug-eluting stents" for primary percutaneous coronary intervention (PCI), commented Dr. David G. Rizik, an interventional cardiologist and director of the division of heart and vascular medicine at the Scottsdale (Ariz.) Healthcare Hospital. "This was a retrospective review, and the MI population was very heterogeneous. Bare-metal stents have performed well in acute MI patients. If a physician has a doubt about a patient’s willingness or ability to comply with dual antiplatelet therapy, there is nothing wrong with using a bare-metal stent."
The study used data collected in the Myocardial Infarction Data Acquisition System (MIDAS) registry and included all patients who underwent primary PCI for an acute MI at a nonfederal hospital in New Jersey during 2003-2004. The group included 6,172 patients treated with one or more drug-eluting coronary stents only, and 5,833 patients treated with one or more bare-metal stents only. The analysis excluded patients who received both stent types.
Based on New Jersey death registration files, during the 5 years following stent placement, cumulative all-cause mortality in the drug-eluting stent recipients was 16% and was 20% in the bare-metal stent recipients, a statistically significant difference. The rate of cardiovascular death was 8% and 10% in the drug-eluting and bare-metal stent groups, respectively, also a statistically significant difference. Similar, statistically significant differences in favor of improved 5-year total survival and reduced cardiovascular deaths with drug-eluting stents also occurred in both the subset of patients with ST-elevation MI and in patients with non–ST-elevation MI, Dr. Vagaonescu reported.
He and his associates also performed multivariate analyses of mortality rates adjusted by age, sex, race, diabetes, hypertension, renal disease, anemia, cancer, cerebrovascular disease, prior MI, and treatment with a glycoprotein IIb/IIIa inhibitor. All of these multivariate analyses showed statistically significant survival advantages for the patients who received drug-eluting stents.
Another aspect of the analysis showed the dramatic shift toward use of drug-eluting stents for primary PCI during the period studied, which covered the time when the first sirolimus-eluting stent received Food and Drug Administration approval in April 2003, and when the first paclitaxel-eluting coronary stent received FDA approval in March 2004. In 2003, 73% of the 6,027 patients who received a single type of coronary stent for primary PCI in New Jersey received a bare-metal stent. By 2004, this pattern flipped, and 76% of the 5,978 patients who received a single type of coronary stent for primary PCI received a drug-eluting stent. Both years predated the reports in 2006 that first raised awareness of the risk for stent thrombosis in patients who received a drug-eluting stent, especially patients who prematurely stopped dual antiplatelet therapy.
Dr. Vagaonescu said that he had no disclosures. Dr. Rizik said that he had no disclosures.