Understanding Benefit of Oral Anticoagulant Over Antiplatelet Therapy in Atrial Fibrillation Depends on the Quality of International Normalized Ratio Control Achieved by Centers and Countries as Measured by Time in Therapeutic Range

The study examines the impact of variations in the time in therapeutic range (TTR) of oral anticoagulation (OAC) therapy on its effectiveness in patients with atrial fibrillation (AF). Using data from the Atrial Fibrillation Clopidogrel Trial With Irbesartan for Prevention of Vascular Events (ACTIVE W), the researchers found that TTRs varied significantly between centers and countries, ranging from 44% to 78%. Patients treated at centers with TTRs below 65% did not show a benefit over clopidogrel plus aspirin, while those at centers with TTRs above 65% experienced a marked reduction in vascular events. A population-average model suggested that a TTR of 58% is necessary to confidently expect a benefit from OAC. The findings highlight the importance of achieving high TTRs to optimize the benefits of OAC therapy and suggest that health policies should aim for a minimum TTR threshold of 58% to 65% to ensure effective anticoagulation in AF patients.The study examines the impact of variations in the time in therapeutic range (TTR) of oral anticoagulation (OAC) therapy on its effectiveness in patients with atrial fibrillation (AF). Using data from the Atrial Fibrillation Clopidogrel Trial With Irbesartan for Prevention of Vascular Events (ACTIVE W), the researchers found that TTRs varied significantly between centers and countries, ranging from 44% to 78%. Patients treated at centers with TTRs below 65% did not show a benefit over clopidogrel plus aspirin, while those at centers with TTRs above 65% experienced a marked reduction in vascular events. A population-average model suggested that a TTR of 58% is necessary to confidently expect a benefit from OAC. The findings highlight the importance of achieving high TTRs to optimize the benefits of OAC therapy and suggest that health policies should aim for a minimum TTR threshold of 58% to 65% to ensure effective anticoagulation in AF patients.

Benefit of Oral Anticoagulant Over Antiplatelet Therapy in Atrial Fibrillation Depends on the Quality of International Normalized Ratio Control Achieved by Centers and Countries as Measured by Time in Therapeutic Range

November 11, 2008 | Stuart J. Connolly, MA, MD, FRCPC; Janice Pogue, MA, MSc; John Eikelboom, MBBS, MSc, FRACP, FRCPA; Gregory Flaker, MD; Patrick Commerford, MB, ChB, FCP(SA); Maria Grazia Franzosi, PhD; Jeffrey S. Healey, MD, FRCPC; Salim Yusuf, DPhil, FRCPC;