CHICAGO — The use of drug-eluting stents in patients with ST-segment elevation myocardial infarction was associated with 1-year cardiovascular event rates similar to bare-metal stents in the large, nonrandomized National Heart, Lung, and Blood Institute Dynamic Registry, Dr. Timothy Shapiro reported at the annual meeting of the Society for Cardiovascular Angiography and Interventions.
“We expected to demonstrate that drug-eluting stents were a safe strategy short-term for acute MI patients. I did also expect to see lower reintervention rates with drug-eluting stents over the next year. We were somewhat surprised to see there was no difference—and not even a trend—for a lower reintervention rate,” said Dr. Shapiro of Lankenau Institute for Medical Research, Wynnewood, Pa.
Nevertheless, he added, registry data such as these can't be considered the final word on efficacy, particularly since the bare-metal stent (BMS) and drug-eluting stent (DES) populations differed in key ways.
On the one hand, the DES group was higher risk and had more noncardiac comorbid conditions. On the other hand, the group also received more aggressive adjunctive pharmacotherapy in line with changes in clinical practice between 2000–2001, when the BMS patients were enrolled, and 2004, when the DES patients entered the registry.
“This study demonstrates that there's no apparent downside to using drug-eluting stents in MI patients, as some people fear,” said Dr. Shapiro.
“It appears from these registry data to be safe and reasonable to use drug-eluting stents. Whether they're better than bare metal stents or not will be borne out as we do prospective randomized trials,” he said.
The NHLBI Dynamic Registry has been recruiting patients since 1997 to provide pictures of the shifting landscape of real-world percutaneous intervention free of industry sponsorship. The registry does not enroll a random sample of coronary artery disease patients. Instead, it features an enriched population of women and minorities, groups historically underrepresented in clinical trials.
Dr. Shapiro reported on 376 patients who received BMSs and 221 who got DESs for ST-segment elevation MI (STEMI). Many of the patients underwent primary PCI, but others received thrombolytic therapy first and then underwent urgent rescue or elective PCI. Sirolimus was the drug used in 65% of the DESs, with paclitaxel accounting for the remainder.
The 1-year rate of the combined end point of death, repeat myocardial infarction, coronary artery bypass graft surgery, or PCI following hospital discharge was 20.7% in the BMS group and 19.3% in the DES cohort.
The differences between the two groups in terms of any of the individual components of the composite end point also were nonsignificant.
In terms of in-hospital complications and adverse events, the only significant differences between the two groups were in the rates of persistent flow reduction—1.1% in the BMS group and 3.4% with DES—and prolonged chest pain, which occurred in 8.2% of patients in the BMS group and was half as common in those with a DES.
Twenty-six percent of the DES group had diabetes, compared with 19% of the BMS patients, a significant difference. Renal insufficiency also was significantly more common in the DES group.
There were marked differences in procedural anticoagulation. Of the DES patients, 87% were on a glycoprotein IIb/IIIa inhibitor, compared with 65% of the BMS group. The DES group also received less unfractionated heparin, more low-molecular-weight heparin, and more clopidogrel.
The use of ACE inhibitors, statins, and clopidogrel at hospital discharge was more common in the DES group, in keeping with national practice guidelines in place in 2004.