Cryptogenic stroke and TIA: Suggested diagnostic approach while waiting for evaluation and treatment guidelines

Abstract

The etiology of approximately one third of ischemic strokes remains undetermined, resulting in their classification as cryptogenic. 1 One sixth meet the definition of embolic stroke of undetermined source (ESUS). 2 The category cryptogenic is heterogeneous and includes cases with unknown etiology, where two or more competing causes are possible, or where the investigation is incomplete. ESUS occurs in the absence of lacunar infarcts, significant stenosis in pre-and cerebral arteries, or cardiac conditions with high risk of embolism, such as atrial fibrillation. Treatment is challenging: it is unknown whether standard secondary prevention provides sufficient protection against recurrence in all cases, while an empiric strategy of routinely administered anticoagulation appears to be both harmful

Atrial fibrillation in cryptogenic stroke and TIA patients in The Nordic Atrial Fibrillation and Stroke (NOR-FIB) Study: Main results

“…As common high-risk factors and mechanisms of stroke can be systematically excluded (i.e. carotid stenosis, PFO) before the diagnosis CS is made and ICM is inserted, 11 , 19 this evaluation strategy is in our opinion robust enough for the current practice. With completed work-up before ICM insertion and early start of monitoring for 1 year, the rate of missing occult AF in CS patients is supposed to be low.…”

Recent advances in the management of transient ischemic attacks

“…At present, comprehensive cardiac imaging can be accomplished by transthoracic (TTE) or transesophageal (TEE) echocardiography or both ( Table 2 ). These two complementary approaches to ultrasonic cardiac imaging provide both morphologic and functional information about cardiac performance, uncovering abnormalities that must be factored in during risk stratification ( Table 2 ), and TTE favors the evaluation of left ventricular contractility, mitral valve performance, left atrial volume, and the possible presence of right-to-left shunts 71 , 72 . By contrast, TEE offers increased resolution and sensitivity for left atrial pathology, including the left atrial appendage (LAA) and the interatrial septum; TEE also can provide information about the aortic arch and the potential presence of complex atherosclerotic plaques as a source of artery-to-artery cerebral embolism ( Table 2 ).…”

“…Cardiac CT or MRI may also complement or replace ultrasound-based cardiac assessment in the future, at least in selected populations. Incorporation of this cardiac imaging data into the patient’s risk stratification will facilitate the development of a management plan tailored to the specific patient 71 , 72 . Additionally, prolonged cardiac monitoring for intervals longer than 30 days, particularly using implantable loop recorders, has increased the detection of paroxysmal arrhythmias, particularly occult atrial fibrillation 73 – 76 .…”