Biodegradable polymer drug-eluting stents reduce the risk of stent thrombosis at 4 years in patients undergoing percutaneous coronary intervention: a pooled analysis of individual patient data from the ISAR-TEST 3, ISAR-TEST 4, and LEADERS randomized trials

Selected in European Heart Journal by G.G. Toth

References

Authors

Giulio G. Stefanini et al.

Reference

Eur Heart J 2014 Marc 24

Published

March 2014

Link

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My Comment

Background

The persistence of durable polymer coating after completion of antiproliferative drug release has been identified as a cornerstone for chronic inflammatory response, and so it is considered to be the potential culprit of very late (>1yrs) stent thrombosis. Biodegradable polymers supposed to diminish chronic inflammatory reactions by ‘behaving’ bare-metal stents on long term, after completion of drug release. This meta-analysis derived from three large randomized trials (ISAR-TEST 3, ISAR-TEST 4, and LEADERS) examines long term follow-up of patients with biodegradable polymer DES vs. patients with durable polymer sirolimus eluting stents (SES).

Findings

Baseline:

- 4062 patients were considered for the analysis, 2358 pts in the biodegradable polymer DES group (Yukon Choice, Translumina, Germany or Biomatrix Flex, Biosensors, US) vs. 1704 pts in the durable polymer SES (Cypher Select, Cordis, US) group. Follow-up was 4 years.

Findings:
  •  As primary efficacy endpoint, risk of target lesion revascularization was found to be significantly lower among patients treated with biodegradable polymer DES, as compare to durable polymer SES (HR 0.56, 95% CI 0.35-0.90, p=0.015).
  •  As primary safety endpoint, risk of definite stent thrombosis was found to be significantly lower among patients treated with biodegradable polymer DES, as compared to durable polymer SES (HR 0.22, 95% CI 0.08-0.61, p=0.004).
  •  As secondary endpoint, risk for probable or definite stent thrombosis was found to be reduced among patients treated with biodegradable polymer DES, as compared to durable polymer SES (HR 0.68, 95% CI 0.46-1.01, p=0.054).
  •  At landmark analysis between 1 to 4 years, lower risk of myocardial infarction was found among patients treated with biodegradable polymer DES, as compared to durable polymer SES (HR 0.59, 95% CI 0.37-0.95, p=0.031).

My comments

Findings are really encouraging to believe that biodegradable polymer is indeed the promising way to go in the field of metallic drug-eluting stents. Theory is logical and data are supporting the concept.
However it is important to keep in mind that Cypher is a ‘historical reference’: for instance struts were markedly thicker as compared to most of the DESs recently available (~150um vs ~60-90um) leaving a larger thrombotic surface behind to get healed.
Summarizing, these data emphasize that there is indeed marked difference in outcome with one or another type of DES, which might be importantly related to the type of polymer. However, this needs to be evaluated with the currently available, much finer and developed technologies, as well.

1 comment

  • Hafeez Ahmed 11 May 2014

    Very recently one of the article showed higher event rate with polymer free DES (like Yukon) as compared to durable polymer DES. It probably showed that polymer is necessary for proper drug delivery at the vessel wall and biodegradable polymer may be the polymer of choice.