Transcranial Doppler for stratification of high-risk morphology of patent foramen ovale in patients with cryptogenic stroke

Transcranial Doppler With Microbubbles: Screening Test to Detect and Grade Right-to-Left Shunt After an Ischemic Stroke: A Literature Review

Right-to-left shunt, mainly due to patent foramen ovale (PFO), is likely responsible for ≈5% of all ischemic strokes and 10% of those occurring in young and middle-aged adults. Randomized clinical trials demonstrated that, in selected young and middle-aged patients with otherwise cryptogenic acute ischemic stroke and high-risk PFO, percutaneous PFO closure is more effective than antiplatelet therapy alone in preventing recurrence. However, PFO is generally a benign finding and is present in about one-quarter of the population. Therefore, in clinical practice, identifying PFOs that are likely to be pathogenetic is crucial for selecting suitable patients for PFO closure to prevent recurrent stroke and to avoid potentially harmful and costly overtreatment. Contrast transthoracic echocardiography has a relatively low sensitivity in detecting PFO, whereas transesophageal echocardiography is currently considered the gold standard for PFO detection. However, it is a relatively invasive procedure and may not always be easily feasible in the subacute setting. Contrast transcranial Doppler is a noninvasive, inexpensive, accurate tool for the detection of right-to-left shunt. We conducted a literature review on the use of contrast transcranial Doppler to detect and grade right-to-left shunt after an acute ischemic stroke and present a clinical workflow proposal for young and middle-aged patients.

European Stroke Organisation (ESO) Guidelines on the diagnosis and management of patent foramen ovale (PFO) after stroke

Patent foramen ovale (PFO) is frequently identified in young patients with cryptogenic ischaemic stroke. Potential stroke mechanisms include paradoxical embolism from a venous clot which traverses the PFO, in situ clot formation within the PFO, and atrial arrhythmias due to electrical signalling disruption. The purpose of this guideline is to provide recommendations for diagnosing, treating, and long-term managing patients with ischaemic stroke and PFO. Conversely, Transient Ischaemic Attack (TIA) was not considered an index event in this context because only one RCT involved TIA patients. However, this subgroup analysis showed no significant differences between TIA and stroke outcomes. The working group identified questions and outcomes, graded evidence, and developed recommendations following the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach and the European Stroke Organisation (ESO) standard operating procedure for guideline development. This document underwent peer-review by independent experts and members of the ESO Guideline Board and Executive Committee. The working group acknowledges the current evidentiary gap in delineating an unequivocal diagnostic algorithm for the detection of PFO. Although transoesophageal echocardiography is conventionally held as the most accurate diagnostic tool for PFO identification, its status as the 'gold standard' remains unsubstantiated by rigorously validated evidence. We found high-quality evidence to recommend PFO closure plus antiplatelet therapy in selected patients aged 18-60 years in whom no other evident cause of stroke is found but a PFO (i.e. PFO-associated stroke). The PASCAL classification system can be used to select such candidates for PFO closure. Patients with both a large right-to-left shunt and an atrial septal aneurysm benefit most from PFO closure. There is insufficient evidence to make an evidence-based recommendation on PFO closure in patients older than 60 and younger than 18 years. We found low quality evidence to suggest against PFO closure in patients with unlikely PFO-related stroke according to the PASCAL classification, except in specific scenarios (Expert Consensus). We suggest against long-term anticoagulation in patients with PFO-associated stroke unless anticoagulation is indicated for other medical reasons. Regarding the long-term AF monitoring after PFO closure, the working group concluded that there remains significant uncertainty regarding the risks and benefits associated with the use of long-term cardiac monitoring, such as implantable loop recorders. This document provides additional guidance, in the form of evidence-based recommendations or expert consensus statements, on diagnostic methods for PFO detection, and medical management after PFO closure.