ATLANTA — Treatment with the investigational direct thrombin inhibitor dabigatran proved safe and effective across the entire spectrum of risk in patients with atrial fibrillation in a secondary analysis of data from the drug's pivotal trial with more than 18,000 patients.
Finding that the lower dose of dabigatran tested cut the stroke and systemic embolization rate as well as warfarin while leading to significantly fewer major bleeds than warfarin in low-risk atrial fibrillation patients potentially opens the door to offering low-risk patients a better anticoagulant option than aspirin, Dr. Jonas Oldgren said at the annual meeting of the American College of Cardiology.
“Today, low-risk patients are treated with no anticoagulant or only with aspirin, which is clearly less effective. The so-called low-risk patients really need anticoagulant treatment, because low-risk is not no-risk. They have a 2%-3% risk of stroke per year, or about a 25% risk over 10 years. We don't treat them with warfarin because of the bleeding risk, but dabigatran is a much safer drug,” said Dr. Oldgren, head of the coronary care unit at Uppsala (Sweden) University, and a co-investigator in the Randomized Evaluation of Long Term Anticoagulant Therapy (RE-LY) trial.
The new analysis assessed the performance of the three treatments tested in three patient subgroups divided based on their CHADS2 scores (see table). For the analysis, Dr. Oldgren divided the patients into three roughly equal-sized groups by their scores: 5,775 with a score of 0 or 1; 6,455 patients with a score of 2; and 5,882 patients with a score of 3-6. Among the warfarin-treated patients the time in the target international normalized ratio range was similar in all three subgroups, about two-thirds of the time in the study.
For the primary efficacy end point of preventing stroke and systemic embolism the higher dabigatran dosage surpassed warfarin in all three CHADS2 subgroups, while the lower dabigatran dosage showed noninferiority across all three risk subgroups. For the primary safety end point of major bleeds, the lower dabigatran dosage performed better than warfarin in all three risk subgroups while the higher dabigatran dosage showed noninferiority.
Dr. Oldgren has received consultant fees, lecture fees, and grant support from Boehringer Ingelheim, and lecture fees from Astra Zeneca. Boehringer Ingelheim sponsored the trial.
'Today, low-risk patients are treated with no anticoagulant or only with aspirin, which is clearly less effective.'
Source DR. OLDGREN
Source Elsevier Global Medical News