James A Reiffel1, Atul Verma2, Peter R Kowey3, Jonathan L Halperin4, Bernard J Gersh5, Mitchell S V Elkind6, Paul D Ziegler7, Rachelle E Kaplon8, Lou Sherfesee9, Rolf Wachter10. 1. Department of Medicine, Division of Cardiology, Vagelos College of Physicians and Surgeons, Columbia University, 630 West 168th Street, New York, NY. Electronic address: jar2@columbia.edu. 2. Department of Cardiology, Southlake Regional Health Centre, 596 Davis Dr, Newmarket, ON, Canada. Electronic address: atul.verma@utoronto.ca. 3. Department of Internal Medicine-Cardiology, Lankenau Institute for Medical Research, 100 Lancaster Ave, Wynnewood, PA. Electronic address: KoweyP@MLHS.ORG. 4. The Cardiovascular Institute, Mount Sinai Medical Center, 1190 5th Ave, New York, NY. Electronic address: jonathan.halperin@mountsinai.org. 5. Department of Cardiovascular Medicine, Mayo Clinic, 200 First St. SW, Rochester, MN. Electronic address: Gersh.Bernard@mayo.edu. 6. Department of Neurology, Vagelos College of Physicians and Surgeons, and Department of Epidemiology, Mailman School of Public Health, Columbia University, 710 West 168(th) Street, #182, New York, NY. Electronic address: mse13@cumc.columbia.edu. 7. Diagnostics, Cardiac Rhythm and Heart Failure, Medtronic, Inc., 8200 Coral Sea St NE, Mounds View, MN. Electronic address: paul.david.ziegler@medtronic.com. 8. Diagnostics, Cardiac Rhythm and Heart Failure, Medtronic, Inc., 8200 Coral Sea St NE, Mounds View, MN. Electronic address: rachelle.k.kaplon@medtronic.com. 9. Diagnostics, Cardiac Rhythm and Heart Failure, Medtronic, Inc., 8200 Coral Sea St NE, Mounds View, MN. Electronic address: lou.sherfesee@medtronic.com. 10. Clinic and Policlinic for Cardiology, University Hospital Leipzig, Liebigstraße 20, Leipzig, Germany. Electronic address: Rolf.Wachter@medizin.uni-leipzig.de.
Abstract
BACKGROUND: Reducing atrial fibrillation (AF)-related stroke requires timely AF diagnosis, but the optimal monitoring strategy is unknown. OBJECTIVE: We used insertable cardiac monitor (ICM) data from the REVEAL AF study to compare AF detection rates by various short-term continuous monitoring (STM) strategies. METHODS AND RESULTS: Patients without known AF, but with CHADS2 scores ≥3 (or = 2 with ≥1 additional AF risk factor) received an ICM for AF detection. One-time STM strategies were assessed by computing AF incidence at 1, 2, 7, 14, and 30 days post-ICM insertion. Repeated STM strategies (quarterly 24-hour, 48-hour, 7-day, or monthly 24-hour monitoring) were modeled by randomly selecting day(s) within a 30-day window around each nominal evaluation date over a 1-year period (simulated 10,000 times). Endpoints included AF ≥6 minutes, AF ≥1 hour, and daily AF burden ≥1 and ≥ 5.5 hours. The impact of compliance on AF detection was evaluated using daily compliance rates of 85%, 75%, 65% and 55% during follow-up months 1-3, 4-6, 7-9, and 9-12, respectively. Based on data from 385 patients (71.5 ± 9.9 years; CHADS2 score 3.0 ± 1.0) the incidence of AF ≥6 minutes via ICM at 12 months was 27.1% (95% CI, 22.5-31.5%). This exceeded the range of estimated rates from all modeled one-time and repeated STM strategies (0.8% for 24-hour Holter monitoring to 10.6% for quarterly 7-day monitoring). Findings were similar for all AF endpoints. Modeled non-compliance reduced AF detection by 4.5% to 22.9%. CONCLUSIONS: Most AF episodes detected via ICMs would go undetected via conventional STM strategies, thus preventing optimal prophylaxis for adverse consequences.
BACKGROUND: Reducing atrial fibrillation (AF)-related stroke requires timely AF diagnosis, but the optimal monitoring strategy is unknown. OBJECTIVE: We used insertable cardiac monitor (ICM) data from the REVEAL AF study to compare AF detection rates by various short-term continuous monitoring (STM) strategies. METHODS AND RESULTS:Patients without known AF, but with CHADS2 scores ≥3 (or = 2 with ≥1 additional AF risk factor) received an ICM for AF detection. One-time STM strategies were assessed by computing AF incidence at 1, 2, 7, 14, and 30 days post-ICM insertion. Repeated STM strategies (quarterly 24-hour, 48-hour, 7-day, or monthly 24-hour monitoring) were modeled by randomly selecting day(s) within a 30-day window around each nominal evaluation date over a 1-year period (simulated 10,000 times). Endpoints included AF ≥6 minutes, AF ≥1 hour, and daily AF burden ≥1 and ≥ 5.5 hours. The impact of compliance on AF detection was evaluated using daily compliance rates of 85%, 75%, 65% and 55% during follow-up months 1-3, 4-6, 7-9, and 9-12, respectively. Based on data from 385 patients (71.5 ± 9.9 years; CHADS2 score 3.0 ± 1.0) the incidence of AF ≥6 minutes via ICM at 12 months was 27.1% (95% CI, 22.5-31.5%). This exceeded the range of estimated rates from all modeled one-time and repeated STM strategies (0.8% for 24-hour Holter monitoring to 10.6% for quarterly 7-day monitoring). Findings were similar for all AF endpoints. Modeled non-compliance reduced AF detection by 4.5% to 22.9%. CONCLUSIONS: Most AF episodes detected via ICMs would go undetected via conventional STM strategies, thus preventing optimal prophylaxis for adverse consequences.