Cost-effectiveness of outpatient cardiac monitoring to detect atrial fibrillation after ischemic stroke

Background and purpose: Extending the duration of continuous electrocardiography after ischemic stroke detects more new cases of atrial fibrillation, which is an important and treatable cause of stroke, but the cost-effectiveness of this approach is unknown. Therefore, we performed a cost-utility analysis of outpatient cardiac monitoring after ischemic stroke. Methods: Using a Markov model, we determined the lifetime cost and utility of warfarin therapy in a hypothetical cohort of 70-year-old patients with atrial fibrillation, prior stroke, and no contraindication to warfarin therapy. Meta-analysis was used to determine the yield of outpatient cardiac monitoring. Results: Outpatient cardiac monitoring would detect 44 new cases of atrial fibrillation for every 1000 patients monitored. This would result in a gain of 34 quality-adjusted life-years at a net cost of $440 000. Therefore, the cost-utility ratio of outpatient cardiac monitoring would be $13 000 per quality-adjusted life-years gained. Outpatient monitoring remained cost-effective throughout a wide range of model inputs in sensitivity analyses, including changes in the cost and yield of monitoring. Conclusions: By identifying patients with paroxysmal atrial fibrillation who will benefit from anticoagulation, outpatient cardiac monitoring is cost-effective after ischemic stroke over a wide range of model inputs. The optimal duration and method of monitoring is unknown.