Aims: Late stent thrombosis has been documented in on- and off-label populations. Stent thrombosis is more frequently in higher risk patients and there is still scarce data about the impact on late adverse cardiac events. The aim therefore is to determine the 3-year safety and effectiveness of Sirolimus-Eluting Stent (SES) (Cypher®) implantation in patients with multivessel disease and to compare outcomes with the historical results of the two arms of the Arterial Revascularisation Therapies Study (ARTS-I).
Methods and results: ARTS-II is a 45 centre, 607 patient single-arm study. Three years outcomes were compared to the outcome of the historical cohorts of ARTS-I using the same inclusion and exclusion criteria and major adverse cardiac and cerebrovascular events (MACCE) definitions. Patients were stratified by clinical site to ensure that at least 1/3 had 3-vessel disease to achieve a number of treated lesions per patient comparable to ARTS-I. Stent thrombosis was re-adjudicated using the ARC definitions. An angiographic coronary score to characterise lesion complexity was applied to allow the identification of patients who might benefit the most from multivessel stenting.
In ARTS-II, 46.6% of the patients underwent 3-vessel treatment as compared to 18.0% in ARTS-I percutaneous coronary intervention (PCI) (n=600) with bare metal stents (BMS). Diabetes was present in 26.2% in ARTS-II as compared to 17.3% in ARTS-I. In ARTS-II, patients received on average 3.7 stents resulting in a mean total stented length of 72.5 mm. The 3-year survival rate in ARTS-II was 97.0%, comparable to the 95.6% and 96.0% of the historical surgical (n=605) and PCI cohorts of ARTS-I. The death/cerebrovascular accident (CVA)/myocardial infarction (MI) event free survival rate in ARTS-II was 91.7%, versus 89.1% (p=0.1) and 87.2% (p=0.007) in ARTS-I coronary artery bypass graft (CABG) and PCI cohorts, respectively. Freedom from revascularisation in ARTS-II was 85.5%, lower than in ARTS-I CABG (93.4%; p<0.001) but higher than in ARTS-I PCI (73.7%; p<0.001) cohorts. MACCE free survival was 80.6% in ARTS-II, comparable to ARTS-I CABG (83.8%; p=0.21) but superior to ARTS-I PCI (66.0%; p<0.0001). The incidence of stent thrombosis (ARC any) in ART-II was 6.4% (39/607 patients).
Conclusions: Despite the higher clinical and angiographic risk profile, the overall MACCE rate at three years was lower in ARTS-II than in the ARTS-I PCI and comparable to ARTS-I CABG. However, the re-intervention rate in ARTS-I CABG remained significantly lower than in ARTS-II.