PMD20 COST EFFECTIVENESS ANALYSIS OF IMPLANTABLE CARDIAC MONITORS TO DETECT ATRIAL FIBRILLATION AFTER CRYPTOGENIC STROKE

Abstract

Cryptogenic strokes (CS) are those with no known cause after standard diagnostic tests, but intermittent atrial fibrillation (AF) can be missed. Implantable cardiac monitors (ICMs) allow long-term monitoring for AF which, if identified, anticoagulants can be given to reduce secondary stroke risk. This study assessed the cost-effectiveness of ICMs compared with standard of care monitoring (SoC) for detecting AF after at least 24 hours of external ECG monitoring in CS patients. A two-stage de novo economic model was developed to assess the costs and benefits of ICMs compared with SoC. The first stage of the model was a short-term patient flow model to identify CS patients with AF who have been detected and are then prescribed anticoagulation treatment and those who are undetected and remain on antiplatelet treatment. The second stage of the model was a long-term Markov model which captures the lifetime costs and benefits of AF patients on either anticoagulation or antiplatelet treatment. Results of a clinical effectiveness systematic review identified one randomised controlled trial (CRYSTAL-AF) that provided data for an ICM compared with SoC and was used to populate the model. CRYSTAL-AF demonstrated that over 36 months, the ICM detected AF in 30% of patients compared with 3% in the SoC arm. The de novo economic model estimated the incremental cost of an ICM compared with SoC is £1,687 and the incremental quality adjusted life year (QALY) gain is 0.07, resulting in an incremental cost effectiveness ratio (ICER) of £24,875. The cost-effectiveness results indicate that ICMs could be considered a cost-effective use of NHS resources at a £20,000 – £30,000 threshold compared with SoC for patients who have had a CS and no AF has been detected after at least 24 hours of external ECG monitoring.