Pouliot, Erika

Introduction: Recent trials using insertable cardiac monitors (ICMs) show high rates of atrial fibrillation (AF) in those at risk of developing AF based on demographics. Further identifying subsets who could benefit most from ICMs is desirable. We evaluated if the recently-developed HAVOC risk score which has predicted AF in cryptogenic stroke patients also predicts AF detection by ICMs in those without a recent stroke. Methods: Participants from the prospective REVEAL AF study, which reported frequent clinically unrecognized AF in patients at risk for AF (CHADS 2 scores ≥3 or =2 with ≥1 additional risk factor), with ICM data and not on anti-arrhythmic drugs were included. Ischemic stroke <1 year ago excluded participation. HAVOC scores were calculated using points for hypertension (2), age ≥75 (2), valvular disease (2), vascular disease (1), obesity (1), congestive heart failure (4), and coronary artery disease (2). Prior stroke, an AF outcome, generally not a cause, is not included. Score classification is: low (0-4), intermediate (5-9), or high (10-14). Corresponding AF detection rates were compared via the log-rank test. Results: Among 391 participants, 95 (24%), 241 (62%), and 55 (14%) had low, intermediate, and high HAVOC scores, respectively. At 18 months, AF incidence was significantly less for those with low (19.5%) vs intermediate (32.1%) or high (34.2%) scores (p=0.045, Figure). At 18 months, AF incidence was similar among those with (n=79) vs. without (n=312) a history of remote stroke (27.1% vs. 29.9%; p>0.05, median time from stroke to ICM insertion=4 years). Conclusions: The HAVOC risk score identified a subset of high risk individuals at greatest risk of developing AF. AF incidence rates were similar among those with and without prior remote stroke. Remote strokes may not be a strong predictor of AF in this population. HAVOC scores could be a useful approach to identify those at high likelihood of manifesting AF, as best documented by long-term monitoring.