Abstract 138: Cost-Effectiveness of Insertable Cardiac Monitors to Identify Atrial Fibrillation After Stroke Attributed to Large-Artery or Small-Vessel Disease

Abstract

Introduction: Identification of atrial fibrillation (AF) in patients with stroke is critical for secondary stroke prevention with guideline-recommended oral anticoagulation (OAC). The randomized STROKE AF trial evaluating patients with ischemic stroke attributed to large-artery or small-vessel disease (LAD/SVD) found that insertable cardiac monitors (ICMs) were more likely to detect AF than standard of care (SoC) using intermittent external ECG monitors. However, the cost-effectiveness of ICMs in this population is not known. This study aimed to evaluate the cost-effectiveness of ICMs to detect new AF in patients with LAD/SVD stroke in the U.S. Methods: Using patient data from STROKE AF (N=492, median CHA 2 DS 2 -VASc=5.0), a lifetime Markov model was developed to assess the cost-effectiveness of ICM vs. SoC from a payer perspective. SoC was based on the frequency of ECG/Holter monitoring observed in the trial. AF detection was assumed to result in a switch from aspirin to OAC, unless precluded by prior bleeds. Lifetime risks of stroke and bleeding events were based on underlying presence of AF and the safety and efficacy of the treatment received. Future costs/effects were discounted at 3% annually to adjust to present values. Sensitivity analyses were conducted to assess uncertainty. Results: ICM was associated with a gain of 0.17 quality-adjusted life years (QALYs) versus SoC (6.63 vs. 6.46), driven by higher incidence of OAC and consequent reduction in lifetime ischemic strokes, with 53 fewer strokes projected per 1,000 patients. Total lifetime per-patient costs were $65,989 and $59,703 in the ICM and SoC arms, respectively. The incremental cost-effectiveness ratio was $37,760 per QALY gained compared to SoC (under the $50,000/QALY threshold considered highly cost-effective in the U.S.). Cost-effectiveness improved further in the subset with CHA 2 DS 2 -VASc≥6. In the patients at highest risk of AF detection (left atrial enlargement, heart failure, obesity, or prolonged QRS), the cost/QALY was $22,016. Conclusions: ICMs are likely to be cost-effective in the U.S. for the diagnosis of AF in the population with stroke attributed to LVD or SVD. This strategy was most cost-effective in patients with high CHA 2 DS 2 -VASc scores and those at greatest risk of AF.