Clinical outcomes with 6 months dual antiplatelet therapy after implantation of Biolimus-A9 drug eluting coronary stents

IntroductionDuration of dual antiplatelet therapy (DAPT) following drug eluting stent (DES) implantation remains poorly defined. Endothelialisation of biodegradable polymer biolimus-eluting stents occurs early, and 6 months DAPT may be adequate.AimsWe evaluated long term outcome in patients treated with biolimus-eluting stents who were treated with 6 months DAPT. Endpoints included cardiac death and non-fatal stent thrombosis occurring 6 to 12 months after stent implantation.Methods692 patients (77.2% male), aged 65.6 ± 12.5 years received biolimus-eluting DES (March 2008 -November 2011). Vital status was tracked through the Medical Research Information Service. Episodes of non-fatal stent thrombosis, (Academic Research Consortium definition) between months 6 and 12 were tracked via systematic database searches (5 PCI centres).ResultsPresentations included acute coronary syndrome (47.2%) and stable coronary disease (52.8%). Vessels treated included left main stem (6.8%), left anterior descending (37.4%), circumflex (19.1%), right coronary artery (34.5%) and saphenous vein graft (2.1%) respectively. High-risk subsets included diabetes (15.6%); AHA type C lesions (35.1%) and chronic total occlusions (12.8%). During median follow-up of 700 days (0 to 1392) there were 42 deaths (6.1%); 4.2% at 0-6 months, 1.0% at 6-12 months and 0.9% at > 12 months. Of the 7 deaths between 6 and 12 months, one death was adjudicated as possible stent thrombosis. There were no cases of non-fatal known stent thrombosis. All cause mortality accrued with smooth decremental incidence. Statistical examination showed no evidence of event clustering between 6 and 12 months.ConclusionsAfter implantation of biodegradable polymer biolimus-eluting coronary stents, 6 months DAPT appears to be adequate, safe and effective.