Stent thrombosis after successful sirolimus-eluting stent implantation.

BACKGROUND: Stent thrombosis (ST) is a rare but devastating complication of coronary stent implantation, occurring in 0.5% to 1.9% of patients with bare metal stents. The incidence of ST with drug-eluting stents is less well studied, particularly among patients outside of clinical trials. METHODS AND RESULTS: The aim of this study was to evaluate the incidence and potential risk factors for ST in patients receiving sirolimus-eluting stents (SES) in the "real world" after commercial release in the United States in April 2003. All 652 patients who underwent SES implantation (776 lesions treated) at our institution between April and October 2003 were followed up prospectively after the procedure (median follow-up 100 days). During that period, 7 patients (1.1%, 95% CI 0.4% to 2.2%) developed ST within a range of 2 to 13 days, and 1 patient had an ST-elevation myocardial infarction on day 39 with evidence of thrombus within the SES at angiography. Patients with an ST had significantly smaller final nominal balloon diameters (2.75 versus 3.00 mm, P=0.04), and in 4 (57%) of the 7 patients with ST versus 1.7% of patients without ST (P<0.001), antiplatelet therapy had been discontinued after the procedure. Among the ST patients, 1 died and 5 had myocardial infarctions. CONCLUSIONS: In this single-center experience, the incidence of ST after SES implantation was approximately 1%, which is within the expected range of bare metal stents. The discontinuation of antiplatelet therapy was strongly associated with the development of ST in this patient population.

Advances in drug eluting stents - focus on the Endeavor(®) zotarolimus stent.

Coronary artery disease remains one of the leading causes of death in the United States. Over the last 30 years, the development of coronary artery angioplasty and stenting has drastically reduced mortality during acute coronary syndromes while also reducing symptoms of chronic coronary artery disease. Unfortunately, the placement of stents in a coronary artery can be complicated by in-stent thrombosis or restenosis. In 2003-2004, a new generation of stents was introduced to the market with the goal of reducing the rate of restenosis. These stents, called drug eluting stents (DES), are coated with a pharmacological agent designed to reduce the neointimal hyperplasia associated with restenosis. Within a year, approximately 80% of all percutaneous coronary interventions performed within the US involved placement of a DES. In 2006, a controversy arose about the possibility of a statistically significant increased risk of acute stent thrombosis associated with DES especially when used for an "off label" indication. This risk was attributed to delayed endothelization. This controversy has led to a reduction in the use of DES along with longer use of dual platelet inhibition with aspirin and clopidogrel. Recently Medtronic introduced a new DES to the market called the Endeavor(®) stent - a zotarolimus eluting stent.

Malfunctions and adverse events associated with off-label use of biliary stents in the peripheral vasculature.

Biliary stents are approved by the U.S. Food and Drug Administration only to treat biliary strictures resulting from cancer. However, these devices are often used "off-label" to treat peripheral vascular disease. This study was designed to determine the number and type of malfunctions and adverse events associated with off-label use of biliary stents in the peripheral vasculature. Confirmed biliary stent malfunctions and adverse events were identified by reviewing biliary stent-related adverse events reported to the U.S. Food and Drug Administration between January 2003 and December 2006. The annual number and type of biliary stent malfunctions and adverse events and the annual number of off-label biliary stent implants were determined. More than one million biliary stents were implanted off-label in the peripheral vasculature during the study period. Most biliary stent malfunctions (81.2% of 1036 malfunctions) and adverse events (87.9% of 561 adverse events) occurred during off-label stent use in the peripheral vasculature. From 2003 to 2006, the annual number of malfunctions increased 80% and adverse events more than doubled, although malfunction and adverse event rates did not significantly increase. Stent malfunctions were most often the result of premature dislodgement or deployment. Retained product, additional percutaneous interventions, or surgery were the most frequently observed adverse events associated with off-label stent use. Thirteen deaths were reported during off-label use. Off-label use of biliary stents in the peripheral vasculature occurs frequently and is increasing in rate. Most adverse events and device malfunctions associated with biliary stent use occur during off-label use. Endovascular treatment of peripheral arterial disease is an important therapy that has benefited many patients. Efforts should be directed at improving the evaluation of peripheral vascular device performance to better identify the patient subsets that will most benefit from this promising therapy.

Complete resolution of a mitral valve vegetation with anticoagulation in seronegative antiphospholipid syndrome.

Antiphospholipid syndrome (APS) is a disorder characterized by recurrent venous or arterial thrombosis and/or fetal loss; involvement of cardiac valves is also seen. A seronegative variant has been described previously. We report a case of a woman with recurrent pregnancy loss, prior strokes, and a negative workup for known antiphospholipid antibodies. During her current pregnancy, she presented with acute stroke and mitral valve vegetation. Her workup for antiphospholipid syndrome and other thrombophilias remained negative even after the stroke. Her mitral valve vegetation resolved completely with aspirin, heparin, and warfarin. We believe this to be the first report of complete resolution of valvular vegetation with antiplatelet and anticoagulant therapy alone in a patient with seronegative antiphospholipid syndrome. Moreover, this appears to be the first report of stroke associated with this condition.