DES or Bare-Metal Stents for Primary PCI? New Meta-Analysis Provokes Debate

April 27, 2012

April 26, 2012 (Novara, Italy) — Results of the first meta-analysis reporting on long-term clinical outcomes, out to three years, with drug-eluting stents (DES) compared with bare-metal stents in the setting of primary angioplasty for ST-elevation MI (STEMI) have divided opinion [1].

The authors, led by Dr Giuseppe De Luca (Ospedale Maggiore della Carità, Novara, Italy), highlight the fact that use of DES was associated with a "significant and sustained" reduction in target vessel revascularization (TVR), without significant differences in cumulative stent thrombosis, reinfarction, or death. "The results of the present study, based on individual patients' data, provide strong evidence of the beneficial effects of [DES] during primary PCI in STEMI," they state.

But in an invited commentary [2], Dr James M Brophy (Royal Victoria Hospital, Montreal, QC) says this "landmark analysis" is open to interpretation; he points to the "worrisome" findings in the study of a significant, 50% increase in the risk of late (more than one year) reinfarction with DES and an almost doubling of very late stent thrombosis.

The results of the meta-analysis also apply only to first-generation stents, the Cypher (sirolimus-eluting) and the Taxus (paclitaxel-eluting) stents, so the relevance of the outcomes to clinical practice today, which often involves the use of newer-generation stents, remains somewhat unclear. Both the authors and editorialist agree that further research is needed.

DES Over Bare-Metal Stents for Primary Angioplasty in STEMI?

Asked by heartwire whether he would recommend use of a DES or bare-metal stent in a patient with STEMI, Brophy said: "My message to clinicians who are DES believers is, 'Avoid in patients likely to have compliance issues with long-term dual antiplatelet drugs, high risk of bleeding, or upcoming planned elective surgery.' Message to clinicians who are unconvinced about the risk/benefit ratio [of DES]: 'This is a reasonable position while awaiting other results. Do not feel intimidated or coerced into accepting newer is better.'

"Given the uncertainty about improvements and safety with DES and their increased cost, it seems that rather than simply adopting them without good evidence, a more rational approach is to perform more research in the area," Brophy stresses.

On the issue of newer-generation DES, DeLuca et al say that recent studies have shown that these--with their thinner, fracture-resistant stent struts and novel biocompatible polymers--"are associated with significantly improved clinical outcomes and stent-thrombosis rates."

But Brophy says: "It is true that newer-generation stents now exist. The question is 'Is it guaranteed that newer is always better?' Bottom line is that we don’t know about newer DES, but we should be careful before assuming they are better. We do know that bare-metal stents work well, although they could be improved in terms of decreasing repeat interventions."

Very Late Stent Thrombosis With First-Generation DES "Bears Discussion"

DeLuca and colleagues explain that DES were initially shown to be safe and effective, at least in short-term follow-up, for primary PCI, but then came the concerns about a higher risk of late stent thrombosis, which was believed to be a particular problem in the setting of STEMI.

The aim of their work--the Drug-Eluting Stents in Primary Angioplasty (DESERT) Cooperation--was to perform a pooled patient-level meta-analysis of randomized trials to evaluate the risks and benefits of DES compared with bare-metal stents in those undergoing primary PCI for STEMI. They included trials from the literature--including BASKET-AMI, HORIZONS-AMI, and SESAMI--and presentations from scientific meetings, from January 2000 to June 2011. Individual patient data were obtained in a total of 6298 patients, 63.2% of whom were randomized to DES, the remainder to bare-metal stents.

The primary end point for the study was mortality; secondary end points included reinfarction, TVR, and stent thrombosis (definite or probable according to Academic Research Consortium definitions) at long-term follow-up.

At a mean of 3.3 years of follow-up, DES implantation reduced the occurrence of TVR by 43% (12.7% vs 20.1% with bare-metal stents; HR 0.57; p<0.001) without any significant difference in terms of cumulative mortality (HR 0.85), reinfarction (HR 1.12), or stent thrombosis (HR 1.13).

The researchers do acknowledge, however, an increase in very late (more than one year) infarction--6.6% with DES vs 3.0% with bare-metal stents (HR 1.57; 95% CI 1.08–2.27) and stent thrombosis (3.1% with DES vs 1.4% with bare-metal stents; HR 1.89, 95% CI 1.13–3.15), which they say "bears discussion."

Whether the newer-generation DES would fare better remains to be seen, they add. "Future randomized trials are needed to evaluate the safety and efficacy of these [newer] DES in the setting of primary PCI in STEMI, especially coupled with the benefits from more potent and/or prolonged dual antiplatelet therapy."

De Luca has no conflicts of interest; disclosures for the coauthors are listed in the paper. Brophy has no disclosures.