Safety and Efficacy of Sirolimus- and Paclitaxel-eluting Coronary Stents
Stone GW, Moses JW, et al.
N Engl J Med, 2007;356:998–1008.
Following reports of increased stent thrombosis and myocardial infarction, the safety of drug-eluting stents (DES) has recently been questioned. Researchers performed pool analysis of data from four double-blind trials in which 1,748 patients were randomly assigned to receive either sirolimus-eluting stents (SES) or bare-metal stents (BMS), and from five double-blind trials in which 3,513 patients were randomly assigned to paclitaxel-eluting stents (PES) or BMS. Results noted that four-year rates of stent thrombosis were 1.2% in the SES group versus 0.6% in the BMS group and 1.3% in the PES group versus 0.9% in the BMS group. Notably, after 12 months the study found five episodes of stent thrombosis in patients with SES versus none in patients with BMS, against nine episodes in patients with PES versus two in patients with BMS. The study concluded that stent thrombosis after one year was more common with both SES and PES than with BMS.
Impact of Platelet Reactivity after Clopidogrel Administration on Drug-eluting Stent Thrombosis
Buonamici P, Marcucci R, et al.
J Am Coll Cardiol, 2007;49(24):2312–17.
This study was designed to test whether non-responsiveness to clopidogrel as revealed by high in vitro post-treatment platelet reactivity is predictive of drug-eluting stent thrombosis. Researchers conducted a cohort study in which 804 patients who had experienced successful sirolimus-eluting stent (SES) or paclitaxel-eluting stent (PES) implantation were assessed for post-treatment platelet reactivity after a loading dose of 600mg of clopidogrel. The study end-point was the incidence of definite/probable early, subacute and late stent thrombosis after a six-month follow-up. The study revealed that incidence of definite/probable stent thrombosis was 3.1%. Fifteen per cent of patients were not responsive to clopidogrel. A stent thrombosis incidence of 8.6% was recorded in non-responders and of 2.3% in responders. The study concluded that non-responsiveness to clopidogrel is a strong independent predictor of stent thrombosis in patients receiving SES or PES.
Incidence and Predictors of Drug-eluting Stent Thrombosis During and After Discontinuation of Thienopyridine Treatment
Airoldi F, Colombo A, et al.
Key drawbacks linked to drug-eluting stents (DES) include the need for prolonged aspirin and thienopyridine therapy along with the risk of stent thrombosis (ST). This cohort study included over 3,021 patients successfully treated in 5,389 lesions with DES. Detailed patient information was collected on antiplatelet therapy. Researchers analysed the incidence of ST over an 18-month follow-up period. ST occurred in 1.9% of patients at 18 months, while 1.4% experienced the event within six months of stent implantation. Acute myocardial infarction occurred in 79% of patients and death in 39% of patients with ST. The median interval from discontinuation of thienopyridine therapy to ST was 13.5 days for the first six months and 90 days between six and 18 months. On multivariable analysis, the strongest predictor for ST within six months of stenting was discontinuation of thienopyridine therapy. The study concluded that in the first six months, thienopyridine therapy was the major determinant of ST. The study highlighted, however, that insufficient information is available to determine whether there is benefit in continuing a thienopyridine beyond this period.
Transcatheter Closure of Congenital Ventricular Septal Defects – Results of the European Registry
Carminati M, Butera G, et al.
Eur Heart J, 2007;28(19):2361–8.
This study aimed to report the experience of over 20 European referral centres on transcatheter closure of congenital ventricular septal defects (VSDs). Implantation of transcatheter devices was attempted in 430 patients with VSDs. The following anatomical types were found: 119 muscular, 250 peri-membranous, 16 multiple and 45 residual postsurgery. The median VSD size was 7mm and fluoroscopy time 33 minutes. Devices implanted were Amplatzer muscular or membranous devices in 364 patients, patent ductus arteriosus (PDA) devices in 12 patients, atrial septal defect (ASD) devices in seven patients, Starflex in seven patients and coils in nine patients. The procedure was successful in 95% of cases. Complications were noted with device embolisation in five cases, aortic regurgitation in 14 cases and tricuspid regurgitation in 27 cases, Multivariate analysis highlighted that the only variables associated with a risk of the occurrence of complication were age and weight. Factors for the development of congenital atrioventricular block (cAVB) were device type and VSD location. The study concluded that transcatheter closure of congenital VSDs offers encouraging results and that complications are limited.