Author + information
- Doug Coyle, PhD,
- Kathryn Coyle, MSc,
- Vidal Essebag, MD, PhD,
- David H. Birnie, MD,
- Kamran Ahmad, MD,
- Satish Toal, MD,
- John Sapp, MD,
- Jeffrey S. Healey, MD,
- Atul Verma, MD,
- George Wells, PhD and
- Andrew D. Krahn, MD∗ ()
- ↵∗Gordon & Leslie Diamond Health Care Centre, Arrhythmia Service, 9th Floor, 2775 Laurel Street, Vancouver, British Columbia V5Z 1M9, Canada
In patients receiving warfarin due to high risk of thromboembolic events, current guidelines recommend bridging therapy with heparin or low molecular weight heparin (LMWH) during surgery for cardiac pacemakers or implantable cardioverter-defibrillators (1). Bridging therapy is associated with increased costs due to increased need for hospitalization and the high price of LMWH (2). The recent randomized controlled BRUISE CONTROL (Bridge or Continue Coumadin for Device Surgery Randomized Controlled Trial; NCT00800137) of 681 patients undergoing nonemergency device surgery found that patients receiving continued-warfarin therapy experienced significantly fewer clinically significant hematomas than those receiving heparin-bridging therapy (3). In this economic evaluation, we compared treatment with warfarin to bridging therapy with heparin.
From the perspective of the Canadian healthcare system, this study sought to assess the cost effectiveness of continued-warfarin versus heparin-bridging therapy in pacemaker or defibrillator surgery using data from the recent single-blind randomized controlled trial (4). We collected resource use for the initial hospitalization, including anticoagulant usage, hospitalization for intravenous heparin administration (17% of heparin-bridging arm), laboratory tests, and extensions of hospitalization due to complications; and at final follow-up to assess repeat hospitalizations, emergency room visits, and management of complications. Appropriate Canadian unit costs were obtained for all resource use collected and estimated for 2012 to 2013 (5). The primary outcome measure was the incremental cost or cost savings per hematoma avoided with appropriate assessment of the uncertainty around the estimates of costs, outcomes, and incremental cost-effectiveness ratios (4). The effect of a range of factors on the costs within the 2 treatment arms was explored through sensitivity analyses.
The overall cost of continued-warfarin therapy was dramatically lower than heparin-bridging therapy ($218 vs. $2,041; p < 0.001), primarily due to lower costs for medication ($11.57 ± $0.64 vs. $353.91 ± $15.09) and hospitalizations ($41.72 ± $37.81 vs. $1,114.60 ± $164.90). There were more clinically significant hematomas within the bridging-heparin group compared with continued-warfarin group (54 vs. 12, respectively), resulting in a trend for increased hematoma costs per patient in the heparin-bridging group ($511.89 ± $199.26 vs. $118.89 ± $69.50; p = 0.060).
Continued-warfarin therapy had fewer clinically significant hematomas compared with heparin-bridging therapy (3.6% vs. 16.6%; p < 0.001). As continued-warfarin therapy was also less costly, it was dominant. In all replications of the non-parametric bootstrap, continued-warfarin therapy remained dominant indicating little uncertainty in the results. Continued-warfarin therapy remained the dominant treatment strategy in all analyses (Table 1).
In conclusion, continued-warfarin therapy was found to be cost effective compared with bridging-heparin therapy in patients at high risk of thromboembolic events undergoing device surgery, with a cost savings of approximately $1,800 per patient treated. Heparin-bridging therapy was associated with increased incidence of hematomas and consequent hospital stays, as well as higher medication costs. The findings were consistent regardless of the format of heparin used as the bridging therapy and across a range of subgroups. The extent of savings may be mitigated by increasing the degree to which heparin-bridging could be transferred into the community in the 17% of patients who had hospital based heparin, as well as differential drug costs in different health delivery systems. Continued-warfarin therapy results in better outcomes at a lower cost than heparin-bridging therapy in patients requiring anticoagulation therapy who are undergoing surgery for either a pacemaker or defibrillator.
Please note: The BRUISE CONTROL (Bridge or Continue Coumadin for Device Surgery Randomized Controlled Trial) was supported by the Canadian Institutes of Health Research and the Ministry of Health and Long-Term Care of Ontario. The economic analysis was supported by the Canadian Institutes of Health Research. Dr. Essebag has been supported by a Clinician Scientist award from the Canadian Institutes of Health Research. Dr. Sapp has received research funding from Biosense Webster, Philips, and St. Jude Medical; and has served as a consultant for Biosense Webster. Drs. Healey and Birnie have received personnel Mid-Career Investigator awards from the Heart and Stroke Foundation of Ontario (MC7450 and MC7445). Dr. Verma has served as a consultant for Bayer and Boehringer Ingelheim. Dr. Krahn is supported by the Sauder Family and Heart and Stroke Foundation Chair in Cardiology and the Paul Brunes Chair in Heart Rhythm Disorders. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- American College of Cardiology Foundation
- ↵Canadian Agency for Drugs and Technologies in Health. Guidelines for the Economic Evaluation of Health Technologies: Canada. 3rd edition, 2006. Ottawa, Canada: Canadian Agency for Drugs and Technologies in Health, 2006. Available at: http://www.inahta.org/wp-content/themes/inahta/img/AboutHTA_Guidelines_for_the_Economic_Evaluation_of_Health_Technologies.pdf. Accessed November 1, 2014.
- Baladi J.-F.