Age-Dependent Detection of Atrial Fibrillation with Implantable Cardiac Monitors in Patients with Cryptogenic Stroke

BackgroundContinuous monitoring using implantable cardiac monitors (ICMs)results in atrialfibrillation (AF) detection rates of up to 30% in patients with cryptogenicstroke (CS). Although higher age is an independent risk factor for AF, there are no age-specific recommendations for the implantation of ICM.ObjectiveThe aim of this study was to analyzeage-related AFrates in patients with CSand continuous rhythm monitoring, to determine the rates of oral anticoagulation(OAC) and recurrent cerebrovascular events (stroke or transient ischemic attack) inpatients with ICM-detected AF, and to describe the temporal relationship of AFdetection and recurrent cerebrovascular events.MethodsIn this observational study, patients with CS provided with ICMs weresystematically followed. All patients underwent 72-hour electrocardiography monitor-ing, transcranial Doppler ultrasound, and transthoracic echocardiography prior to ICMinsertion. Follow-up included a regular outpatient presentation every 3 months withmedicalhistory,physicalexamination, and interrogation of the ICM.ResultsOne-hundred eighty-six patients (mean age: 65 +/- 12 years, 54% female) wereincluded in this analysis. AF was detected in 6, 27, 56, and 65% (p<0.001) of patientsaged less than 60, 60 to 69, 70 to 79, and more than or equal to 80 years, respectively.All patients with AF under 60 years had an impaired left ventricular systolic function.OAC was initiated in 85% of the patients with AF. Recurrent cerebrovascular eventsoccurred in 34 patients of whom 14 had a diagnosis of AF. In nine patients, AF wasdiagnosed before the occurrence of a recurrent cerebrovascular event.ConclusionAF prevalence increased with age and was absent in CS patients youngerthan 60 years and with preserved left ventricular ejection fraction. The temporalrelationship of AF and recurrent cerebrovascular events was weak.