Journal Club Summary
Methodology Score: 2.5/5
Usefulness Score: 3/5
Pollack CV Jr, et al.
N Engl J Med. 2015 Aug 6;373(6):511-20
This prospective cohort study demonstrated that a new dagbigatran reversal agent, idarucizumab, completely reverses dabigatran’s anticoagulant effects (as measured by dilute thrombin time and eccarin clotting time) in patients with serious bleeding or in need of an urgent procedure. JC attendees found the following weaknesses in this study: very small sample size, was an interim analysis with only 90 patients, lacked a control group, used laboratory tests as surrogate endpoints for the primary outcome, and lacked patient orientated, clinically important/safety outcomes. Dabigatran is currently the only novel oral anticoagulant with an FDA approved reversal agent.
By: Dr. Laura Shoots
(Presented February 2016)
Epi lesson:
Surrogate endpoints
Can be used as a measure of effect for specific treatments and might correlate with clinical outcomes. In the RE-VERSE AD (idarucizumab for dabigatran reversal) study the investigators used dilute thrombin time and ecarin clotting time as surrogate end points for reversal of dabigatran action by the study drug idarucizumab. The actual clinical end point of restoration of hemostasis was a secondary outcome. This was a small study. We need a large clinical study with a control group to confirm that clinical outcomes among patients treated with the reversal agent were better. Be wary of studies using surrogate outcomes when clinical outcomes could have been used.
By: Dr. Venkatesh Thiruganasambandamoorthy
