Malapposition in drug-eluting stents. Much more common and much less serious than we thought

Original title: Incidences, Predictors, and Clinical Outcomes of Acute and Late Stent Malapposition Detected by Optical Coherence Tomography After Drug-Eluting Stent Implantation Reference: Im E. et al. CircCardiovascInterv. 2014 Jan 14. [Epubahead of print]

 

This paper analyzed the imaging of 351 patients by optical coherence tomography (OCT) who received drug-eluting stents over 356 lesions between 2009 and 2011. The drug-eluting stents used were sirolimus, everolimus, zotarolimus, and biolimus. Over half of the patients (62 %) exhibited acute malapposition in the OCT analysis, while the rate of persistent and acquired malapposition was 31% and 16% respectively. 69% of patients who showed post implant, immediate resolved during monitoring. The independent predictors of acute malapposition were calcified lesion (OR 11.19, P < 0.001), stent length greater than 25 mm (OR 3.8, p = 0.033) and that the lesion, showed the basal stenosis diameter had > 70% (OR 2.45, p = 0.015).

In OCT monitoring an average of 175 ± 60 days after DES implantation, we observed that a third of stent with acute malapposition persisted in such malapposition (persistent late malapposition) and this was typically located at the edges (72 %). A volume of malapposition stent of 2.56 mm³ or greater divided the population between those with late persistent malapposition from those that resolved acute malapposition spontaneously. The late acquired malapposition was detected in 15% of lesions, usually found in the body of the stent and was associated with thrombus or plaque prolapse after implantation. No events including death, myocardial infarction, or stent thrombosis in patients with late malapposition were observed during follow-up 28.6 ± 10.3 months after DES

Conclusion:

Late diagnosed malpositions (acute, late, persistent, and acquired) by OCT were relatively common although different factors influenced each. The clinical course of these patients over two years of follow-up was very favorable.

Editorial comment

Most analyzed patients received dual antiplatelet therapy for at least 12 months and 2nd generation DES what possibly buffered the occurrence of events in the monitoring group that traditionally was considered at increased risk, at least in thrombosis.

SOLACI.ORG

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