The use of drug-eluting stents (DES) in patients with acute myocardial infarction (AMI) has recently generated concern. In two meta-analyses (De Luca et al and Kaleson et al) , the use of early-generation DES resulted in a lower risk of repeat revascularization compared with bare-metal stents (BMS) in patients with AMI, but the DES group had a 2-fold increased risk for very late stent thrombosis (after the first year). These findings were attributed, at least in part, to the permanent polymer coating on the DES that has “an early protective effect against stent thrombosis and a late proinflammatory and prothrombotic effect,” which may be responsible for the delayed arterial healing, incomplete endothelialization, uncovered stent struts, inflammation, and persistent fibrin deposition that was observed.
Second-generation DES with biodegradable polymers provide controlled drug release with subsequent degradation of the polymer and a lower risk for stent thrombosis than first generation DES.
In the prospective, randomized COMFORTABLE AMI (Comparison of Biolimus Eluted From an Erodible Stent Coating With Bare Metal Stents in Acute ST-Elevation Myocardial Infarction) trial, 1161 patients with STEMI were randomized to receive biolimus (an equipotent sirolimus analogue)-eluting stents or BMS, after which they were followed-up for 12 months. Compared with BMS, the use of biolimus-eluting stents with a biodegradable polymer resulted in a lower rate of major adverse cardiac events (4.4% absolute reduction).
COMFORTABLE AMI Trial Results
|
Endpoint
|
Bare metal stent
(n=582)
|
Biolimus-eluting stent (n=575)
|
Hazard ratio (HR),
P value
|
| Composite of cardiac death, target vessel-related reinfarction, and ischemia-driven target-lesion revascularization |
8.7%
|
4.3%
|
HR, 0.49;
P =0.004
|
| Target vessel–related reinfarction |
2.7%
|
0.5%
|
HR, 0.20;
P=0.01
|
| Ischemia-driven target-lesion revascularization |
5.7%
|
1.6%
|
HR, 0.28;
P<0.001
|
(Adapted from Räber L et al. JAMA 2012 Aug 22/29; 308:77.)
The findings for the composite endpoint were consistent across stratified analyses for diabetes mellitus, renal failure, thrombus aspiration, small-vessel disease, and lesion length.
Unfortunately, the biolimus-eluting stent is currently not approved by the U.S. FDA.
Do concerns of late stent thrombosis influence your decision to use DES in the setting of AMI?
Given concerns about overuse of DES, should we be using DES less — or more — frequently in AMI patients?
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