Drug-eluting stents (DES) with biodegradable polymers can allow controlled drug release followed by subsequent degradation of the polymer, leaving a in essence a bare-metal stent.  In patients undergoing primary percutaneous coronary intervention (PCI) for acute ST-elevation myocardial infarction (STEMI), this may prevent the delayed vessel healing that is thought to be caused at least in part by the persistence of durable polymer components.

In this randomised, single-blinded, multi-centre study, 1161 patients presenting with STEMI were assigned in a 1:1 ratio either to receive a biolimus eluting (n=575), or a bare-metal stent (n=582).  The primary endpoint was the rate of major adverse cardiac events, which was a composite of cardiac death, target-vessel related infarction, and ischaemia driven target-lesion revascularisation at one year.

At one year 24 patients (4.3%) receiving a biolimus-eluting stent with a biodegradable polymer suffered a major adverse cardiac event, compared to 49 (8.7%) of patients receiving bare-metal stents (P=0.004); this was largely due to a reduction in target-lesion revascularisation.  There were no statistically significant differences in rates of cardiac death or stent thrombosis.

Conclusion:

The use of biolimus-eluting stents with a biodegradable polymer, when compared to bare-metal stents, led to a lower rate of major adverse cardiac events at one year in patients undergoing primary PCI for STEMI.

• Räber L, Kelbæk H, Ostoijc M et al.  Effect of Biolimus-Eluting Stents With Biodegradable Polymer vs Bare-Metal Stents on Cardiovascular Events Among Patients With Acute Myocardial Infarction.  The COMFORTABLE AMI Randomized Trial.  JAMA 2012; 308(8):777-787.