ESC: Local Standards Affect Stroke Drug Benefits
Analysis of drug comparison trial shows quality control affects benefits of new treatment
MONDAY, Aug. 30 (HealthDay News) -- After analyzing a trial of dabigatran versus warfarin for preventing stroke in patients with atrial fibrillation, researchers have found that the benefit of using new treatments may be influenced by local standards of care. This research has been published online Aug. 29 in The Lancet to coincide with the European Society of Cardiology Congress, held from Aug. 28 to Sept. 1 in Stockholm, Sweden.
Lars Wallentin, M.D., of Uppsala University in Sweden, and colleagues studied data on 18,113 patients randomly assigned to warfarin or dabigatran to determine whether the benefits of the latter were consistent in those centers that had sub-par international normalized ratio (INR) quality control according to each center's mean time in therapeutic range (cTTR).
The researchers found fewer strokes with increasing cTTR in the warfarin group, but no decrease in intracranial bleeding, and they found cTTR had no influence on the effect of dabigatran 110 or 150 mg versus warfarin for stroke prevention. Centers with lower cTTR, however, showed higher risk for cardiovascular mortality, bleeding, and adverse cardiovascular events. The researchers determined that, at these centers, the advantages of dabigatran over warfarin were considerably greater.
"The benefits of 150 mg dabigatran at reducing stroke, 110 mg dabigatran at reducing bleeding, and both doses at reducing intracranial bleeding versus warfarin were consistent irrespective of centers' quality of INR control. For all vascular events, non-hemorrhagic events, and mortality, advantages of dabigatran were greater at sites with poor INR control than at those with good INR control. Overall, these results show that local standards of care affect the benefits of use of new treatment alternatives," the authors write.
The study was funded by Boehringer Ingelheim; several authors disclosed financial relationships with Boehringer Ingelheim and other pharmaceutical and/or medical device companies.