April 24th, 2012

Meta-Analysis Compares Drug-Eluting and Bare-Metal Stents for Primary Angioplasty

A new meta-analysis comparing drug-eluting stents (DES) and bare-metal stents (BMS) in patients with MI has provoked opposing take-away messages from the study authors and an editorialist. The authors emphasize the reduction in target-vessel revascularization (TVR) associated with DES, but the editorialist focuses on several potential DES weaknesses suggested by the study.

In the paper, published in the Archives of Internal Medicine, members of the Drug-Eluting Stent in Primary Angioplasty (DESERT) Cooperation pooled patient data from 11 clinical trials in which nearly 6300 patients were randomized to either sirolimus-eluting or paclitaxel-eluting stents or BMS.  After a mean follow-up of 1201 days, DES was associated with a significant reduction in TVR but there were no significant differences in death, reinfarction, or stent thrombosis:

  • TVR: 12.7% for DES vs. 20.1% for BMS, HR 0.57, CI 0.50-0.66, p<0.001
  • Mortality: 8.5% vs. 10.2%, HR 0.85, CI 0.70- 1.04, p = 0.11
  • Reinfarction: 9.4% vs. 5.9%, HR 1.12, CI 0.88-1.41, p = 0.36
  • Stent thrombosis: 5.8% vs. 4.3%, HR 1.13, CI 0.86-1.47, p = 0.38

However, after 2 years there was a significant increase in the risk of stent thrombosis associated with the DES group (HR 2.81, CI 1.28-6.19, p=0.04).

The findings, write the authors,

provide strong evidence of the beneficial effects of SES and PES during primary PCI in STEMI. With follow-up as late as 6 years, a robust and sustained decrease in TVR was noted with use of these DES. Although the rates of late reinfarction and ST progressively increased, with the difference becoming statistically significant after 2 years in patients receiving SES and PES, the HR for mortality, while not significantly different between DES and BMS, favored DES.

In an accompanying editorial, James Brophy notes that the difference in TVR “may be artificially inflated by protocol-mandated, rather than clinically driven, repeated angiograms.” Brophy  also states that analyzing the data with a different statistical approach leaves open the possibility that DES is associated with a twofold increase in the risk of reinfarction. Brophy provides the follow perspective on choosing BMS versus DES for MI patients:

An informed patient with STEMI should be told that substituting DES for BMS in 100 patients likely results in no mortality differences but approximately 5 fewer repeat revascularizations at the cost of 1 additional late reinfarction with a possibility that this risk may be substantially higher.

Click here to read a response to the editorial by DESERT senior author Gregg Stone. Comments on this topic should also be posted here.

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