Research on drug-eluting stents (DES) has yielded conflicting data about the safety and efficacy of DES in patients with myocardial infarction (MI). Analysis of data from a large registry of stents suggested that DES are not associated with inferior clinical outcomes. In fact, adjusted rates of death, revascularization, and reinfarction were lower among patients who received a DES than among patients who received a bare-metal stent (BMS).

Laura Mauri, MD, MSC, Brigham and Women's Hospital, Boston, MA, reported on an observational study that involved the evaluation of patients who had a stent inserted for acute MI in the state of Massachusetts. Of the 7216 patients identified in the database, 4016 received a DES and 3200 received a BMS. Dr. Mauri explained that because there is a bias in selecting the type of stent for an individual patient, propensity score matching was done, and the patients in the 2 groups were matched on as many as 63 patient-, procedure-, and hospital-related variables. Data on 2629 patients in each group formed the basis of the analysis.

The researchers sought to determine if there was a signal of harm associated with DES in patients with acute MI. Dr. Mauri reported that the overall outcomes favored DES. Specifically, the 2-year, risk-adjusted mortality rate was significantly lower for patients with DES than for those with BMS (10.4% vs 13.2%; p=0.002). The rate of revascularization was also significantly lower in association with DES (15.5% vs 20.8%; p<0.001). The rate of reinfarction was lower, but the difference was not significant (9.5% vs 11%; p=0.08).

“These findings are reassuring,” Dr. Mauri said. “Although neither bare-metal stents nor drug-eluting stents were originally approved in the setting of acute myocardial infarction, it is probably the most important condition that we treat with stents. This study confirms that the same benefits that DES offer other patients in preventing restenosis exist for patients with MI, and there doesn't appear to be any trade-off in increased risk of repeat MI or death.” She added that patients with a DES must be able to take prolonged dual antiplatelet therapy with aspirin and a thienopyridine for one year.

Because patients with MI are at higher risk for late stent thrombosis than patients with stable angina, longer follow-up is needed to monitor the outcome over time. Dr. Mauri said that she and her colleagues plan to continue follow-up and re-examine the findings when more data are available.