AIM: BMS or DES for STEMI? Jury may still be out
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In the continuing battle of the stents, a meta-analysis comparing PCI with drug-eluting stents (DES) and bare-metal stents (BMS) in STEMI patients showed that DES came out on top in terms of reducing target vessel revascularization (TVR) but was linked to higher rates of late reinfarction and stent thrombosis. An accompanying editorial questioned whether the higher rates of reinfarction may be a costly addition to healthcare, without proven safety benefits.

The study and accompanying editorial were published in the April 24 issue of the Archives of Internal Medicine.

“Concerns have emerged regarding a higher risk of stent thrombosis after DES implantation, especially in the setting of STEMI,” wrote Giuseppe De Luca, MD, PhD, of the Eastern Piedmont University in Novara, Italy, and colleagues.

To evaluate the long-term safety and effectiveness of DES compared with BMS, De Luca et al performed the DESERT (Drug-Eluting Stents in Primary Angioplasty) meta-analysis of 11 randomized trials of DES for STEMI that were conducted between January 2000 and June 2011 and identified through a search of the MEDLINE and CENTRAL databases.

The study included a total of 6,298 patients, of which 3,980 were randomized to DES and 2,318 were randomized to BMS. Of those randomized to receive DES, 99 percent received sirolimus-eluting stents (SES, 26.7 percent) or paclitaxel-eluting stents (PES, 72.3 percent).

The primary endpoint of the analysis was mortality and secondary endpoints focused on reinfarction rates, TVR and stent thrombosis.

The researchers noted that higher percentages of DES patients received dual-antiplatelet therapy during the three-year follow-up period compared with patients who received BMS. A total of 432 patients died at long-term follow-up. Mortality rates did not significantly differ between the DES and BMS groups, 8.5 percent vs. 10.2 percent, respectively. Cardiac mortality rates also did not statistically differ between the two groups, 5.7 percent vs. 6.8 percent, respectively.

De Luca and colleagues noted that stent thrombosis occurred in 267 patients. The long-term rate of stent thrombosis for the DES and BMS groups were reported to be 5.8 percent vs. 4.3 percent, respectively.

The authors also reported that 847 patients underwent a TVR. However, rates of TVR were significantly reduced in patients undergoing PCI with DES compared with BMS, 12.7 percent vs. 20.1 percent, respectively.

“The principal finding from our study is that among patients with STEMI undergoing primary PCI, compared with BMS, SES and PES are associated with significant and sustained reductions in TVR, without significant differences in ST [stent thrombosis], reinfarction or death,” the authors wrote.

However, the authors found that after long-term follow-up, rates of stent thrombosis significantly increased for the DES group compared with the BMS group. The same was true for reinfarction rates.

“Early after its introduction, stenting had been avoided in the setting of STEMI because of concerns that implantation of a metallic device within a thrombotic environment such as that of a plaque disruption resulting in myocardial infarction might predispose to ST [stent thrombosis] with resultant vessel occlusion,” the authors wrote. With improvements in DES and stent deployment techniques, many have demonstrated safety of BMS in the STEMI setting; however, many have been concerned with the increased risk of late stent thrombosis associated with DES implantation in STEMI patients.

From the current study, the authors concluded that the lower mortality rates seen with DES use, despite the higher rates of late reinfarction and stent thrombosis, could be explained by the “time-related prognostic impact on in-stent thrombosis.”

The authors concluded that patients with STEMI undergoing primary PCI with DES saw reduced rates of TVR and target-lesion revascularization at long-term follow-up. However, these patients also saw greater rates of late reinfarction and stent thrombosis when compared to those who underwent PCI with BMS. “There were no significant differences in overall or very late mortality, with the point estimate favoring DES in all periods,” the authors summed.

“Despite these worrisome findings [late reinfarction and stent thombosis rates], this study provides reassurance that the DES benefits in STEMI warrant the potential risks,” wrote James M. Brophy, MD, PhD, of the Royal Victoria Hospital, Montreal in Quebec, in an accompanying editorial.

“How clinicians interpret this study will depend on an assessment of its overall quality, precision, and integration with other evidence,” Brophy wrote.

Brophy questioned whether results of the study could be generalizable to real-world populations. In addition, he said that while meta-analysis “often forms the backbone for comparative effectiveness research,” which is predicated on real-world applications in real-world settings.

He also added that the effectiveness of DES over BMS in terms of TVR could be “inflated by protocol-mandated, rather than clinically driven, repeated angiograms.”

Brophy said that the two-fold increase in reinfarctions seen with DES must be ruled out before clinicians can comment on the safety of DES in this patient population.

He added that one important clinical question remains: should patients with STEMI receive DES? “Clearly, DES should be avoided in patients likely to have compliance issues with long-term dual antiplatelet drugs, high risk of bleeding, or upcoming planned elective surgery,” he summed.

“Depending on repeat revascularizations costs, DES instead of BMS after STEMI may be seen as a pricey dessert whose exact caloric and nutritional value remains uncertain,” Brophy summed.