Drug-Eluting Stents versus Bare-Metal Stents in PCI

Results of a pooled patient-level meta-analysis [Arch Intern Med. 2012;172(8):611-621] comparing drug-eluting stents (DES) to bare-metal stents (BMS) in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI) found no significant difference in mortality, nor in reinfarction or stent thrombosis between the 2 types of stent. However, DES was associated with an increased incidence of very late reinfarction and stent thrombosis. The main benefit of DES was a significant reduction in target-vessel revascularization (TVR) compared with BMS. 

Although data have indicated short-term efficacy and safety of DES in patients with STEMI undergoing PCI, concern is emerging on the potentially higher risk of stent thrombosis with DES among patients with STEMI.

To evaluate long-term safety and effectiveness of DES compared with BMS in patients undergoing PCI for STEMI, the current study pooled individual data that met study inclusion criteria from 11 randomized trials comparing DES with BMS in primary PCI for STEMI. Studies included in the pooled analysis had randomized treatment allocation, follow-up data of >1 year, and complete clinical data available.

Studies were not included if the follow-up data were available on <90% of the patients, if the study was ongoing or data were not retrievable, if the overall sample size was <50 patients, and if investigators were unwilling to provide individual patient data.

Data on 6298 patients were available from the 11 trials included in this pooled analysis. Of these, 3980 patients (63.2%) were assigned to DES and 2318 patients (36.8%) were assigned to BMS. Among the DES group, 99% were with sirolimus-eluting or paclitaxel-eluting stents. The length of follow-up varied among these trials from 3 to 6 years.

The primary outcome of the study was mortality. Secondary outcomes were reinfarction, target-vessel revascularization, and stent thrombosis.

At a long-term follow-up of mean 1201 days, the analysis found no significant difference in the primary outcome of mortality in patients undergoing PCI with DES compared with BMS (8.5% vs 10.2%, respectively; hazard ratio [HR], 0.85 [95% confidence interval [CI], 0.70-1.04]) (P=.11). In addition, based on 5849 patients from 9 trials, no difference in cardiac mortality was found between DES and BMS (5.7% vs 6.8%, respectively; HR, 0.84 [95% CI, 0.65-1.09]) (P=.19).

The study also found no difference between DES and BMS in reinfarction (9.4% vs 5.9%, respectively; HR, 1.12 [95% CI, 0.88-1.41]) (P=.36) or stent thrombosis (5.8% vs 4.3%, respectively; HR, 1.13 [95% CI, 0.86-1.47]) (P=.38).

However, after long-term follow-up (after 2 years from the onset of the study), DES was associated with a significantly increased reinfarction rate compared with BMS (HR, 2.06 [95% CI, 1.22-3.49]) (P=.03) and rate of stent thrombosis (HR, 2.81 [95% CI, 1.28-6.19]) (P=.04).

The study did find a significant reduction with DES compared with BMS in the occurrence of TVR (12.7% vs 20.1%, respectively; HR, 0.57 [95% CI, 0.50-0.66]) (P<.001).

Some limitations of the study were the inclusion of highly selected patients in the pooled data with few patients having cardiogenic shock, the lack of sufficient power to show differences in mortality, and current analyses applied only to the paclitaxel-eluting stent (Taxus^®) and sirolimus-eluting stent (Cypher^®).