Bottom line: Based on analysis of completed studies that included directly observed follow-up of study participants, the early risk of stroke after TIA is approximately 15% to 20% at 90 days following the sentinel event.
Citation: Wu CM, McLaughlin K, Lorenzetti DL, Hill MD, Manns BJ, Ghali WA. Early risk of stroke after transient ischemic attack. Arch Intern Med. 2007;167:2417-2422.
What Is the 1-year Ischemia and Mortality Rate for Three Anti-thrombotic Therapies for Early Invasive Management of ACS?
Background: Early interventional or surgical revascularization has improved morbidity and mortality in patients with acute coronary syndrome (ACS). The optimal anti-thrombotic regimen to reduce late ischemic and death rates has not been determined.
Study design: Prospective, open-label randomized control trial.
Setting: 450 academic and community-based institutions in 17 countries.
Synopsis: A total of 13,819 patients were enrolled between August 2003 and December 2005. They were assigned to heparin plus glycoprotein (GP) IIb/IIIa inhibitors (n=4,603), bivalirudin (Angiomax) plus IIb/IIIa inhibitors (n=4,604), or bivalirudin monotherapy (n=4,612).
For patients receiving GP IIb/IIIa inhibitors, a 2×2 factorial design assigned half the heparin and bivalirudin groups to routine upstream GP inhibitor administration (4,605 patients). The other half received selective GP IIb/IIIa inhibitors administration if PCI was indicated (4,602 patients).
At one year, there was no statistically significant difference in ischemia or mortality rate among the three therapy groups. No difference in ischemia rate was detected between the two GP IIb/IIIa inhibitor utilization strategies.
Since the hypotheses and the power for the one-year analysis in this trial were not prospectively determined, the results are considered to be exploratory and hypothesis generating.
Bottom line: At one year, there is no statistically significant difference in ischemia or mortality rate for the three antithrombotic regiments and the two glycoprotein utilization strategies.
Citation: Stone GW, Ware JH, Bertrand ME, et. al. Antithrombotic strategies in patients with acute coronary syndromes undergoing early invasive management. One-year results from the ACUITY trial. JAMA 2007;298:2497-2505.
What Is the PE Risk after Discontinuing Anticoagulation in Patients with Symptomatic VTE?
Background: The natural history of patients with symptomatic VTE who have completed anticoagulation is not well understood.
Study design: Inception cohort using pooled data from a prospective cohort study and one arm of an open-label randomized trial.
Setting: Academic medical centers in Canada, Sweden, and Italy.
Synopsis: Using pooled data from two previous studies, 2,052 patients with a first diagnosis of symptomatic VTE (lower-extremity deep-vein thrombosis [DVT], PE, or both) were evaluated for fatal PE after a standard course of therapy (mean of six months) with a vitamin K antagonist.
Patients were followed for up to 120 months. The investigators found an annual event risk of 0.19-0.49 per 100 person-years for fatal PE. Patients with prolonged immobility, active cancer, and thrombophilia were excluded, as were those with recurrent acute DVT.
Secondary analysis revealed an incidence of any fatal, definite or probable PE within the first year of discontinuing therapy of 0.35%-0.81%.
After the first year, the annual event risk ranged from 0.15-0.40 events per 100 person-years. Patients with advanced age, idiopathic VTE as well as those presenting with PE had higher rates of fatal PE.
Bottom line: There is a real though small (less than 1%) risk of fatal PE in the first year following discontinuation of anticoagulation for the first VTE episode. The optimal course of treatment for patients with idiopathic VTE is yet to be determined.
Citation: Douketis JD, Gu CS, Schulman S, et al. The risk for fatal pulmonary embolism after discontinuing anticoagulant therapy for venous thromboembolism. Ann Intern Med. 2007;147(11):766-774.