ORLANDO, FL—Interim results from a long-term, “real world” study suggest dabigatran etexilate mesylate (Pradaxa) may be safer than warfarin in routine
clinical practice.
The data, which come from a pooled analysis of 2 large US commercial health insurance databases, showed that patients with non-valvular atrial fibrillation (NVAF) who received dabigatran had fewer strokes and major bleeding events than NVAF patients who received warfarin.
The results were presented at the American Heart Association (AHA) Scientific Sessions 2015 (abstract M 2129*).
The research was supported by Boehringer Ingelheim, the company developing dabigatran, and employees from the company were involved in the study.
“Beyond clinical trials, there is a wealth of available health insurance data that provides an excellent opportunity to grow our knowledge of oral anticoagulant use and outcomes for patients,” said study investigator John Seeger, PharmD, DrPH, of Brigham and Women’s Hospital in Boston, Massachusetts.
“These real-world data further define the safety and effectiveness of dabigatran for patients and its use in routine care, and are consistent with the results of the pivotal RE-LY clinical trial.”
Dr Seeger and his colleagues analyzed data collected over 32 months and encompassing 44,672 NVAF patients—22,336 propensity-score-matched patients receiving dabigatran or warfarin for the first time.
The data were collected from 2 insurance databases—Truven MarketScan (18,276 patients per group) and Optum Clinformatics (4060 patients per group).
Patients were followed until they switched or discontinued anticoagulant treatment, experienced an outcome event, or discontinued enrollment. The average follow-up period was 5 months for dabigatran-treated patients and 4 months for warfarin-treated patients.
The primary outcomes of the study were stroke and major bleeding rates.
There were 65 strokes among dabigatran-treated patients (0.73 incidence rate per 100 patient-years) and 78 strokes among warfarin-treated patients (1.08 incidence rate per 100 patient-years).
The investigators said this represents a 28% reduction in stroke risk for dabigatran compared to warfarin. (The hazard ratio was 0.72.)
There were 395 major bleeding events among dabigatran-treated patients (4.47 incidence rate per 100 patient-years) and 459 events for warfarin-treated patients (6.42 incidence rate per 100 patient-years).
This represents a 26% reduction in the risk of major bleeding events with dabigatran compared to warfarin. (The hazard ratio was 0.74.)
The investigators said effectiveness assessments beyond the first 6 months of therapy were limited by the short average follow-up time. But future analyses from this long-term study program will yield more stable estimates.
This study is part of an ongoing research program to evaluate prescribing patterns and real-world safety and effectiveness of novel oral anticoagulants, including dabigatran, for reducing stroke risk.
*Data in the abstract differ from data presented at the meeting.