Monday, September 27, 2010
warfarin anticoagulantia aspirin
Dual, triple anticoagulation therapy for AF may triple bleeding risk
16 September 2010
MedWire News: Adding clopidogrel, with or without aspirin, to warfarin in anticoagulation therapy for atrial fibrillation (AF) may increase patients’ bleeding risk at least three-fold, research indicates.
This risk is much higher than previously recognized, and further still, such combination therapy does not appear to notably reduce nonfatal and fatal ischemic stroke risk, say Morten Hansen (Copenhagen University Hospital, Denmark) and colleagues.
The researchers used national registries to assess the post-discharge medications and outcomes of 118,606 Danish patients admitted to hospital for AF.
Patients who collected at least one prescription for a medication after discharge were assumed to have taken the medication.
Hansen et al found that 86.1% of patients took warfarin, aspirin, or clopidogrel monotherapy after discharge.
Dual warfarin-aspirin therapy was more commonly taken after discharge than warfarin-clopidogrel, or clopidogrel-aspirin, at 15.5%, 1.2%, and 2.4%, respectively.
Only 1.1% (n=1261) of patients took warfarin-aspirin-clopidogrel triple therapy.
The findings, published in the Archives of Internal Medicine, showed that over a mean follow-up period of 3.3 years, 11.4% of patients experienced fatal or nonfatal bleeding.
The team found that the highest rates of bleeding occurred among patients taking triple therapy or dual warfarin-clopidogrel therapy, at 15.7% and 13.9%, respectively.
When compared with warfarin monotherapy in Cox proportional hazards modeling, triple therapy and any dual therapy were associated with a significantly increased risk for fatal and nonfatal bleeding, with aspirin-clopidogrel, warfarin-aspirin, warfarin-clopidogrel, and triple therapy each associated with 1.66-, 1.83-, 3.08-, and 3.70-fold increases in risk for fatal and nonfatal bleeding, respectively.
Of note, the risk for ischemic stroke remained higher among patients on aspirin-clopidogrel, warfarin-aspirin, or triple therapy than among those on warfarin monotherapy, with 1.56-, 1.27-, and 1.45-fold risk increases, respectively.
And although warfarin-clopidogrel dual therapy reduced ischemic stroke risk, by 30%, the reduction was nonsignificant.
The researchers conclude: “These results stress that appropriate selection of patients for these therapies is important and that physicians should consider the expected benefits and risks carefully before prescribing combination therapy.”
MedWire (www.medwire-news.md) is an independent clinical news service provided by Current Medicine Group, a trading division of Springer Healthcare Limited. © Springer Healthcare Ltd; 2010
Arch Intern Med 2010; 170: 1433–1441
16 September 2010
MedWire News: Adding clopidogrel, with or without aspirin, to warfarin in anticoagulation therapy for atrial fibrillation (AF) may increase patients’ bleeding risk at least three-fold, research indicates.
This risk is much higher than previously recognized, and further still, such combination therapy does not appear to notably reduce nonfatal and fatal ischemic stroke risk, say Morten Hansen (Copenhagen University Hospital, Denmark) and colleagues.
The researchers used national registries to assess the post-discharge medications and outcomes of 118,606 Danish patients admitted to hospital for AF.
Patients who collected at least one prescription for a medication after discharge were assumed to have taken the medication.
Hansen et al found that 86.1% of patients took warfarin, aspirin, or clopidogrel monotherapy after discharge.
Dual warfarin-aspirin therapy was more commonly taken after discharge than warfarin-clopidogrel, or clopidogrel-aspirin, at 15.5%, 1.2%, and 2.4%, respectively.
Only 1.1% (n=1261) of patients took warfarin-aspirin-clopidogrel triple therapy.
The findings, published in the Archives of Internal Medicine, showed that over a mean follow-up period of 3.3 years, 11.4% of patients experienced fatal or nonfatal bleeding.
The team found that the highest rates of bleeding occurred among patients taking triple therapy or dual warfarin-clopidogrel therapy, at 15.7% and 13.9%, respectively.
When compared with warfarin monotherapy in Cox proportional hazards modeling, triple therapy and any dual therapy were associated with a significantly increased risk for fatal and nonfatal bleeding, with aspirin-clopidogrel, warfarin-aspirin, warfarin-clopidogrel, and triple therapy each associated with 1.66-, 1.83-, 3.08-, and 3.70-fold increases in risk for fatal and nonfatal bleeding, respectively.
Of note, the risk for ischemic stroke remained higher among patients on aspirin-clopidogrel, warfarin-aspirin, or triple therapy than among those on warfarin monotherapy, with 1.56-, 1.27-, and 1.45-fold risk increases, respectively.
And although warfarin-clopidogrel dual therapy reduced ischemic stroke risk, by 30%, the reduction was nonsignificant.
The researchers conclude: “These results stress that appropriate selection of patients for these therapies is important and that physicians should consider the expected benefits and risks carefully before prescribing combination therapy.”
MedWire (www.medwire-news.md) is an independent clinical news service provided by Current Medicine Group, a trading division of Springer Healthcare Limited. © Springer Healthcare Ltd; 2010
Arch Intern Med 2010; 170: 1433–1441
# posted by roodbont @ 10:43 AM 
