DETECTION OF ATRIAL FIBRILLATION IN CRYPTOGENIC STROKE: A CONSENSUS DOCUMENT OF HELLENIC NEUROLOGICAL SOCIETY, HELLENIC SOCIETY OF CARDIOLOGY AND HELLENIC SOCIETY OF CEREBROVASCULAR DISEASES

Abstract

Stroke is a major worldwide cause of mortality and disability with multiple risk factors. Atrial fibrillation represents the most important cardiac risk factor for ischemic stroke. Early detection of paroxysmal atrial fibrillation (PAF) is paramount for effective secondary stroke prevention. Prolonged heart rate monitoring is appropriate in patients with cryptogenic stroke and transient ischemic attack (TIA) with negative baseline diagnostic work-up including repeat 24-hour Holter monitoring. Long term monitoring devices have the potential to dramatically increase the incidence of PAF detection in patients with cryptogenic stroke, leading to timely initiation of anticoagulation therapy that confers the greatest benefit in terms of recurrent stroke reduction in these patients. Implantable cardiac monitors have documented the highest yield in detecting PAF in patients with cryptogenic ischemic stroke since they can prolong substantially the duration of cardiac monitoring (up to three years). Long-duration holter monitoring and portable cardiac telemetry devices are second-line, non-invasive diagnostic adjuncts. Despite the lack of clear international recommendations on the optimal diagnostic work-up in patients with cryptogenic ischemic stroke, prolonged heart rate monitoring devices should be offered to all patients with ischemic stroke of undetermined cause following a negative extensive, baseline diagnostic work-up, including 24-hour Holter monitoring. Oral anticoagulation (including vitamin K antagonists and non-vitamin K antagonist oral anticoagulants) has been shown not to be beneficial (compared to aspirin) in secondary stroke prevention. High HAVOC score (>4), cortical/cerebellar infarct location, frequent (≥500/24hrs) atrial premature beats and severe left atrial enlargement have been associated with higher yield of implantable cardiac monitoring AF detection in patients with cryptogenic stroke. The efficacy of anticoagulation for secondary stroke prevention is only established for patients with PAF. Prolonged cardiac monitoring is essential for the appropriate selection of cryptogenic stroke patients with clear indication for anticoagulation in the context of secondary stroke prevention.