Atrial Cardiomyopathy: An Emerging Cause of the Embolic Stroke of Undetermined Source

Abstract

Nearly 30% of ischemic strokes have an unknown cause, which are referred to as cryptogenic strokes (CS). Imaging studies suggest that a large proportion of these patients show features that are consistent with embolism, and thus the term embolic stroke of undetermined source (ESUS) was proposed to describe these CS patients. Atrial cardiomyopathy predisposes to thrombus formation and thus embolic stroke even in the absence of atrial fibrillation (AF). This may provide a mechanistic link with ESUS, suggesting that anticoagulant therapy may be more beneficial than antiplatelet therapy in ESUS patients with atrial cardiomyopathy. The present review discusses the concept of atrial cardiomyopathy and ESUS and the relationship between them based on the mechanisms and clinical evidence, suggests that atrial cardiomyopathy may be a potential mechanism of ESUS, and highlights a theoretical basis that supports that anticoagulant therapy may be more applicable to ESUS patients with atrial cardiomyopathy and aims to help us better understand and identify the risk of ESUS, thereby improving the management of these patients in clinical practice.

Ischemia with Nonobstructive Coronary Artery Disease and Atrial Cardiomyopathy—Two Sides of the Same Story?

“…All of these changes adversely impact ventricular filling, leading to manifestations of HF, and ACM is a frequent cause of HFpEF [ 18 ]. At the same time, atrial alterations lead to an atrial prothrombotic state, even in the absence of atrial arrhythmias, and ACM may be in the causal pathway of cardioembolic stroke independently of AF [ 19 ]. There is no standard diagnosis for ACM, and published studies use heterogeneous methods to define ACM, which are mainly related to electrocardiographic abnormalities of the P wave, the presence of AF, abnormal atrial electrophysiologic (EP) properties on EP studies, abnormal atrial histological features, and increased atrial dimensions or atrial dysfunction on different imaging techniques such as echocardiography or CMR [ 20 ].…”

ADAMTS-13 activity in stroke of known and unknown cause: Relation to vascular risk factor burden

“…Embolic stroke of undetermined source (ESUS) describes a cryptogenic stroke with embolic pattern on imaging and accounts for ~17% of all ischemic strokes ( 1 ). It is assumed that a relevant part of ESUS is due to an inapparent cardioembolic mechanism including atrial cardiopathy ( 2 , 3 ) and atrial fibrillation (AF) ( 1 ). However, two randomized controlled trials did not show a superiority of oral anticoagulants over antiplatelet therapy in ESUS ( 4 ), implying that a proper work-up for identifying the most probable mechanism of stroke etiology is still warranted in patients who suffered a cryptogenic stroke.…”

Atrial cardiomyopathy: from cell to bedside

“…11 These studies suggest that ACM may be the primary cause of LA thrombogenesis and resultant CS. 12 Therefore, identifying the value of ACM may help to better understand the risk of CS in patients without AF.…”

“…In addition, some studies have reported that atrial cardiomyopathy (ACM) was a potential source of embolic stroke of undetermined source (ESUS) in ~45% of ESUS patients 11 . These studies suggest that ACM may be the primary cause of LA thrombogenesis and resultant CS 12 . Therefore, identifying the value of ACM may help to better understand the risk of CS in patients without AF.…”