AIMS: Apixaban was superior to aspirin for the prevention of stroke or systemic embolism in participants with subclinical atrial fibrillation (SCAF) in the Apixaban for the Reduction of Thromboembolism in Patients With Device-Detected Subclinical Atrial Fibrillation trial. This was especially true for those with CHA2DS2-VASc score > 4. Understanding the cost-effectiveness of treating SCAF is important for decision-makers. METHODS AND RESULTS: Canadian, UK, German, and US direct healthcare costs [in 2023 US dollars (USD)] were applied to hospitalized events (including strokes and bleeds) and study drugs for all participants with a CHA2DS2-VASc score > 4 to determine the mean cost per participant during the trial (mean follow-up 3.5 years). A daily cost of $0.63, $0.11, $2.26, and $6.06 for apixaban in Canada, the UK, Germany, and the USA was used. If in-trial results were not cost-saving (below $0), the prospective plan was to perform a lifetime cost-effectiveness analysis using a Markov model and a willingness-to-pay of 50 000 USD per quality-adjusted life year (QALY). After considering the cost of study medication and clinical events over 3.5 years, apixaban was dominant (cost-saving and more effective) in Canada (-$2301) and the UK (-$902) but cost more in Germany and the USA ($600 and $1990, respectively). Over a lifetime, treatment with apixaban produced a net gain of 0.107 QALYs, but with costs in both Germany ($2623 more) and the USA ($9110 more), yielding an incremental cost-effectiveness ratio of $24 514 per QALY for Germany and $85 140 for the USA. CONCLUSION: In patients with SCAF and a CHA2DS2-VASc score > 4, apixaban is cost saving in Canada and the UK and cost-effective in Germany. Apixaban was not cost-effective in the USA under the base cost assumption but would be cost-effective at a daily cost of $4.35 and cost saving at $3.59.

• Keywords
• Apixaban, Cost-effectiveness, Stroke prevention, Subclinical atrial fibrillation,
• MeSH
• Cost-Benefit Analysis MeSH
• Aspirin * economics   therapeutic use   adverse effects   MeSH
• Time Factors MeSH
• Stroke prevention & control   economics   etiology   MeSH
• Models, Economic MeSH
• Atrial Fibrillation * economics   diagnosis   complications   drug therapy   MeSH
• Fibrinolytic Agents economics   therapeutic use   adverse effects   MeSH
• Platelet Aggregation Inhibitors * economics   therapeutic use   adverse effects   MeSH
• Factor Xa Inhibitors economics   therapeutic use   adverse effects   MeSH
• Quality-Adjusted Life Years MeSH
• Humans MeSH
• Drug Costs * MeSH
• Pyrazoles * economics   therapeutic use   adverse effects   MeSH
• Pyridones * economics   therapeutic use   adverse effects   MeSH
• Risk Factors MeSH
• Aged MeSH
• Thromboembolism * prevention & control   economics   etiology   diagnosis   MeSH
• Cost Savings MeSH
• Treatment Outcome MeSH
• Check Tag
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Multicenter Study MeSH
• Randomized Controlled Trial MeSH
• Comparative Study MeSH
• Geographicals
• Canada MeSH
• United States MeSH
• Names of Substances
• apixaban MeSH Browser
• Aspirin * MeSH
• Fibrinolytic Agents MeSH
• Platelet Aggregation Inhibitors * MeSH
• Factor Xa Inhibitors MeSH
• Pyrazoles * MeSH
• Pyridones * MeSH