25 Nov Bleeding and Ischemic Events Following Bare Metal vs Drug Eluting Stents

MedicalResearch.com Interview with:
Dean J. Kereiakes, MD FACC, FSCAI
The Lindner Research Center
The Christ Hospital Health Network
Cincinnati, Ohio 45219

Medical Research: What is the background for this study?

Dr. Kereiakes: Bare metal stents (BMS) are a commonly used alternative to drug eluting stents (DES) particularly for patients presenting with acute coronary syndromes or in whom dual antiplatelet therapy (DAPT) has perceived increased bleeding risks. We aimed to determine whether the risks of stent thrombosis and major adverse clinical cardiovascular and cerebrovascular (MACCE; composite of death, MI or stroke) events differ for BMS versus DES and whether the optimal duration of dual antiplatelet therapy differs for BMS or DES. To answer these objectives we performed a propensity matched BMS to DES 0-33 month comparison as well as an analysis of treatment effect among BMS treated patients randomly assigned to 12 versus 30 months of DAPT.

Medical Research: What are the main findings?

Dr. Kereiakes: In 10,026 DES and BMS treated subjects matched exactly on the diagnosis of STEMI and for all remaining (total 55) variables via propensity score using a caliper 0.10, DES were observed to have a significantly lower incidence of stent thrombosis (Academic Research Consortium [ARC] definite/probable definition) from 0 -33 months with a trend (p=0.052) toward a lower incidence of MACCE as well. Among 1687 BMS-treated patients randomly assigned to 30 versus 12 DAPT, stent thrombosis was reduced by longer duration therapy (stratified hazard ratio 0.49; stratified log rank p value 0.24). The 51% reduction in stent thrombosis by longer duration therapy was entirely explained by a reduction in the occurrence of definite stent thrombosis (ARC definition). Bleeding events were increased with longer (30 months) duration DAPT (GUSTO severe- moderate bleeding 2.03% versus 0.9% with shorter therapy; p=0.07). Finally, no difference in mortality (cardiovascular or non-cardiovascular) was observed between the 30 and 12 month treatment groups.

Medical Research: What should clinicians and patients take away from your report?

Dr. Kereiakes: Clinicians and patients should take away the following:

1. BMS are not safer than DES. In fact, BMS have a higher risk for stent thrombosis than DES.
2. The treatment effect benefit of longer (30 months) DAPT compared with shorter (12 months) therapy appears consistent for both DES and BMS. This similarity in treatment effect benefit is reflected by hazard ratio reductions of <1.0 (0.49 for BMS; 0.29 for DES) as well as no statistically significant evidence for treatment duration by stent type interaction (p=0.42).
3. Bleeding risk is increased with longer duration DAPT but fatal bleeding was rare and not different between randomized treatment groups (30 versus 12 months).
4. No differences in mortality were evident between subjects randomly assigned to 30 versus 12 months of DAPT following BMS deployment.

Medical Research: What recommendations do you have for future research as a result of this study?

Dr. Kereiakes: These results will likely inform clinical practice guidelines as well as clinical practice. Despite the widely held perception that BMS are “safer” and require a shorter duration of DAPT than DES, our results demonstrate that BMS have a higher risk for stent thrombosis and derive treatment benefit from longer duration DAPT (30 months versus 12 months) which is consistent with that observed for DES. In BMS treated patients, prolonger thienopyridine (30 months or longer) may provide durable ischemic benefit to increased bleeding risk and requires further study.

Citation:

AHA14 abstract:

Comparison of Ischemic and Bleeding Events After Drug-Eluting Stents or Bare Metal Stents in Subjects Receiving Dual Antiplatelet Therapy: Results from the Randomized Dual Antiplatelet Therapy Study

Last Updated on November 25, 2014 by Marie Benz MD FAAD