Randomized trial of atrial arrhythmia monitoring to guide anticoagulation in patients with implanted defibrillator and cardiac resynchronization devices.

Abstract

AIMS:

Atrial tachyarrhythmias (ATs) detected by implanted devices are often atrial fibrillation or flutter (AF) associated with stroke. We hypothesized that introduction and termination of anticoagulation based upon AT monitoring would reduce both stroke and bleeding.

METHODS AND RESULTS:

We randomized 2718 patients with dual-chamber and biventricular defibrillators to start and stop anticoagulation based on remote rhythm monitoring vs. usual office-based follow-up with anticoagulation determined by standard clinical criteria. The primary analysis compared the composite endpoint of stroke, systemic embolism, and major bleeding with the two strategies. The trial was stopped after 2 years median follow-up based on futility of finding a difference in primary endpoints between groups. A total of 945 patients (34.8%) developed AT, 264 meeting study anticoagulation criteria. Adjudicated atrial electrograms confirmed AF in 91%; median time to initiate anticoagulation was 3 vs. 54 days in the intervention and control groups, respectively (P < 0.001). Primary events (2.4 vs. 2.3 per 100 patient-years) did not differ between groups (HR 1.06; 95% CI 0.75-1.51; P = 0.732). Major bleeding occurred at 1.6 vs. 1.2 per 100 patient-years (HR 1.39; 95% CI 0.89-2.17; P = 0.145). In patients with AT, thromboembolism rates were 1.0 vs. 1.6 per 100 patient-years (relative risk -35.3%; 95% CI -70.8 to 35.3%; P = 0.251). Although AT burden was associated with thromboembolism, there was no temporal relationship between AT and stroke.

CONCLUSION:

In patients with implanted defibrillators, the strategy of early initiation and interruption of anticoagulation based on remotely detected AT did not prevent thromboembolism and bleeding.

CLINICAL TRIAL REGISTRATION:

IMPACT ClinicalTrials.gov identifier: NCT00559988 ( http://clinicaltrials.gov/ct2/show/NCT00559988?term=NCT00559988&rank=1 ).

• Authors: David T Martin, Malcolm M Bersohn, Albert L Waldo, Mark S Wathen, Wassim K Choucair, Gregory Y H Lip, John Ip, Richard Holcomb, Joseph G Akar, Jonathan L Halperin, IMPACT Investigators
• Journal: European heart journal (Eur Heart J) Vol. 36 Issue 26 Pg. 1660-8 (Jul 07 2015) ISSN: 1522-9645 [Electronic] England
• PMID: 25908774 (Publication Type: Comparative Study, Journal Article, Multicenter Study, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)
• Copyright: Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: [email protected].

Chemical References

• Anticoagulants

Topics

• Aged
• Anticoagulants (therapeutic use)
• Atrial Fibrillation (therapy)
• Cardiac Resynchronization Therapy Devices
• Defibrillators, Implantable
• Female
• Humans
• Male
• Middle Aged
• Monitoring, Ambulatory (methods)
• Single-Blind Method
• Stroke (prevention & control)
• Telemedicine (methods)
• Thromboembolism (prevention & control)
• Treatment Outcome
• Wireless Technology