Long-Term Benefit Using DES in STEMI Patients

The current issue of the Journal of Invasive Cardiology addresses the ongoing debate of the future role of drug-eluting stents (DES) on ST-segment elevation myocardial infarction (STEMI) interventions, by presenting the most recent database reported by two studies — RESEARCH, Rapamycin-Eluting Stent Evaluated At Rotterdam Cardiology Hospital and T-SEARCH, Taxus-Stent Evaluated At Rotterdam Cardiology Hospital in Netherlands.¹

It is critical to have a long-term follow-up study comparing the safety and effectiveness of DES with bare-metal stents (BMS) in the STEMI population in the true hospital setting. Prior randomized studies of primary percutaneous coronary intervention (PCI) corroborate the use of BMS. However, DES decrease neointimal proliferation and inhibit smooth muscle migration after stent deployment and hence the rate of subsequent cardiovascular events, predominantly by decreasing the rate of target lesion revascularization.²

Simsek et al showed that sirolimus-eluting stents (SES) and paclitaxel-eluting stents (PES) did not improve safety or efficacy when compared to BMS in STEMI patients in a 6-year follow-up. SES resulted in a significant decrease in mortality, mortality/MI, and MACE rates as compared to BMS, in contrast to the usage of PES. When analyzing the lower mortality rates in the SES group compared to the BMS group, we should realize that patients selected for the use of BMS are usually sicker, have a limited life expectancy, higher bleeding risk, or are thought to be less compliant with the medication. SES and PES showed similar effectiveness and safety profiles. It is important to reaffirm the concern of a higher very long stent thrombosis (VLST) rate with the use of SES. The use of clopidogrel post-DES implantation affected the occurrence of late stent thrombosis of SES patients. The recommended course of standard antiplatelet therapy after DES is longer than after BMS, using clopidogrel for at least 1 year following ACS. The risk of late stent thrombosis has been attributed to the discontinuation of antiplatelet therapy, particularly in the setting of incomplete stent deployment, malapposition, and other high-risk clinical markers.² Addition of costly drugs to the management of STEMI, like clopidogrel, might represent an additional hurdle with patient compliance. The decision to use DES versus BMS is based on appropriate patient selection and an evaluation of the patient’s long-term ability to take antiplatelet agents. The “Antiplatelet Compliance Test” can be used as a tool to decide which stent should be implanted. Another non-issue until recently has been the choice of antiplatelet therapy: clopidogrel or prasugrel. Prasugrel is better recommended for patients at highest risk of a recurrent ischemic event who are able to tolerate it and have no contraindications. A possible alternative is to use prasugrel in the emergent setting where the risk of ST is highest, and then switch to clopidogrel for long-term use.

Brodie et al, in a 15-year single center experience, demonstrated that the frequency of stent thrombosis (ST) post-primary PCI for STEMI is high with both BMS and DES. BMS presented an ongoing increment to at least 11 years, and DES an increase of at least 4.5 years. Following the first year, VLST, reinfarction, and reinfarction of the target vessel were significantly higher with DES compared with BMS. VLST resulted in reinfarction with both BMS and DES, but STEMI was more frequent with DES.³ The HORIZONS-AMI study 3-year follow-up showed that PES had lower rates of ischemia-driven target lesion revascularization after 3 years, with no significant differences in the rates of death, reinfarction, stroke, or stent thrombosis in comparison to BMS.⁴ ST was high (≥ 4.5%) in both groups. These results might lead us to focus our attention on thrombosis. DES may be chosen because of the low overall risk of ST and lower risk of restenosis in patients with STEMI. BMS would be an applicable option in cases where there is higher risk of ST. None of the current data prohibit either therapeutic option.

The rapid emergence of therapeutic options of second-generation DES, such as everolimus and zotarolimus, that demonstrate clear benefits in comparison to SES in early, late, and very late thrombosis, will require further adept efforts to evaluate long-term benefit. Other novel stent concepts, including bioabsorbable stents, nanotechnology, and endothelial progenitor-cell coated stents, also deserve further research.

References

1. Simsek C, Magro M, Boersma E, et al. Comparison of 6-year clinical outcome of sirolimus- and paclitaxel-eluting stents to bare-metal stents in patients with ST-segment elevation myocardial infarction: An analysis of the RESEARCH (Rapamycin-Eluting Stent Evaluated At Rotterdam Cardiology Hospital) and T-SEARCH (Taxus-Stent Evaluated At Rotterdam Cardiology Hospital) registries. J Invasive Cardiol 2011;23:336–341.
2. Mehta S. Textbook of STEMI Interventions. 2nd edition. Malvern: HMP Communications: 2010.
3. Brodie B, Pokharel Y, Fleishman N, et al. Very late stent thrombosis after primary percutaneous coronary intervention with bare-metal and drug-eluting stents for ST-segment elevation myocardial infarction: A 15-year single-center experience. JACC Cardiovasc Interv 2011;4:30–38.
4. Stone GW, Witzenbichler B, Guagliumi G, et al. Heparin plus a glycoprotein IIb/IIIa inhibitor versus bivalirudin monotherapy and paclitaxel-eluting stents versus bare-metal stents in acute myocardial infarction (HORIZONS-AMI): Final 3-year results from a multicentre, randomised controlled trial. Lancet 2011;377:2193–2204.

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From the University of Miami, Miami, Florida.
The authors report no conflicts of interest regarding the content herein.
Address for correspondence: Sameer Mehta, MD, FACC, MBA, 185 Shore Drive South. Miami, FL 33133. Email: mehtas@bellsouth.net