Implantable Cardiac Monitoring in the Secondary Prevention of Cryptogenic Stroke

OBJECTIVE: In this study, we sought to evaluate the impact of implantable cardiac monitoring (ICM) in the prevention of stroke recurrence after a cryptogenic ischemic stroke or transient ischemic attack (TIA). METHODS: We evaluated consecutive patients with cryptogenic ischemic stroke or TIA admitted in a comprehensive stroke center during an 8-year period. We compared the baseline characteristics and outcomes between patients receiving conventional cardiac monitoring with repeated 24-hour Holter-monitoring during the first 5 years in the outpatient setting and those receiving continuous cardiac monitoring with ICM during the last 3 years. Associations on the outcomes of interest were further assessed in multivariable regression models adjusting for potential confounders. RESULTS: We identified a total of 373 patients receiving conventional cardiac monitoring and 123 patients receiving ICM. Paroxysmal atrial fibrillation (PAF) detection was higher in the ICM cohort compared to the conventional cardiac monitoring cohort (21.1% vs 7.5%, p < 0.001). ICM was independently associated with an increased likelihood of PAF detection during follow-up (hazard ratio HR = 1.94, 95% confidence interval CI = 1.16-3.24) in multivariable analyses. Patients receiving ICM were also found to have significantly higher rates of anticoagulation initiation (18.7% vs 6.4%, p < 0.001) and lower risk of stroke recurrence (4.1% vs 11.8%, p = 0.013). ICM was independently associated with a lower risk of stroke recurrence during follow-up (HR = 0.32, 95% CI = 0.11-0.90) in multivariable analyses. INTERPRETATION: ICM appears to be independently associated with a higher likelihood of PAF detection and anticoagulation initiation after a cryptogenic ischemic stroke or TIA. ICM was also independently related to lower risk of stroke recurrence in our cryptogenic stroke / TIA cohort. ANN NEUROL 2020;88:946-955.