Atrial dyssynchrony and left atrial stiffness are risk markers for cryptogenic stroke in patients with patent foramen ovale

A meta-analysis of the association of atrial septal abnormalities and atrial vulnerability

BACKGROUND

The mechanism of cryptogenic stroke (CS) in patients with atrial septal abnormalities remains unclear, and the increased incidence of atrial vulnerability may be one of the reasons. We performed this meta-analysis to clarify the association between atrial septal abnormalities and atrial vulnerability, and to provide evidence-based basis for the prevention and mechanism of CS.

METHODS

We systematically searched for studies on the association between atrial septal abnormalities and atrial vulnerability, and pooled available data on types of atrial septal abnormalities, types of atrial vulnerability, and methods of atrial vulnerability detection. The primary endpoints were the occurrence of atrial arrhythmias or P wave abnormalities. Random-effects models were used to calculate odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

Twelve case-control studies were eligible. Compared with the control group, patients with atrial septal abnormalities had a higher risk of atrial vulnerability (OR: 1.93; 95% CI: 1.13-3.30, P = .02). Data based on stroke patients showed that the group with atrial septal abnormalities had a higher risk of atrial vulnerability than the control group (OR: 2.00; 95% CI: 1.13-3.53, P = .02). However, there was no significant difference in the incidence of atrial vulnerability between the 2 groups of nonstroke patients. Subgroup analysis showed that although atrial septal abnormality increased the risk of atrial vulnerability in the subgroup of atrial septal aneurysm (OR: 1.68; 95% CI: 0.47-5.95, P = .42), the subgroup of atrial fibrillation (AF)/atrial fluster (OR: 1.81; 95% CI: 0.94-3.46, P = .07) and the subgroup of subcutaneous recording system (OR: 1.33; 95% CI: 0.68-2.61, P = .41), the difference was not statistically significant.

CONCLUSIONS

Atrial septal abnormalities can increase the risk of atrial vulnerability, and atrial arrhythmia caused by atrial septal abnormalities may be one of the mechanisms of CS.

The prognostic value of left atrial dyssynchrony measured by speckle tracking echocardiography in the general population

LA dyssynchrony is a predictor of cardiovascular morbidity in various patient populations. However, the prognostic value of LA dyssynchrony as evaluated by two-dimensional speckle tracking (2D-STE) in the general population is unknown. A cohort of 375 participants without atrial fibrillation (AF), ischemic heart disease (IHD), heart failure (HF) or previous ischemic stroke (IS) had an echocardiogram, including LA 2D-STE, performed. LA dyssynchrony was defined as the standard deviation of the time to peak regional LA reservoir strain values. The endpoints were all-cause mortality, a combined endpoint of AF and IS, and a combined endpoint of major adverse cardiovascular events (MACE) comprised of acute myocardial infarction (AMI), HF or cardiovascular death (CVD). During a median follow up of 16.1 years (IQR 15.0-16.3 years), 83 (22%) participants died, 60 (15%) reached the composite endpoint of AF and IS, and 38 (10%) reached the composite MACE endpoint. LA dyssynchrony was a univariable predictor of all-cause mortality (HR 1.07, 95% CI 1.02-1.11, p = 0.001) but was not significantly associated with the combined endpoint of AF and IS (HR 1.05, p = 0.064) nor MACE (HR 1.04, p = 0.22). However, when adjusted for age, LA dyssynchrony did not predict all-cause mortality (HR 1.03, p = 0.28). Similarly, after further adjustments for clinical and echocardiographic parameters LA dyssynchrony did not predict any of the study outcomes. In this general population study, LA dyssynchrony was not an independent predictor of all-cause mortality and did not predict MACE nor a composite outcome consisting of AF and IS.

Atrial Cardiopathy and Sympatho-Vagal Imbalance in Cryptogenic Stroke: Pathogenic Mechanisms and Effects on Electrocardiographic Markers

Recently, atrial cardiopathy has emerged as possible pathogenic mechanism in cryptogenic stroke and many electrocardiographic (ECG) markers have been proposed in order to detect an altered atrial substrate at an early stage. The autonomic nervous system (ANS) plays a well-known role in determining significant and heterogeneous electrophysiological changes of atrial cardiomyocytes, that promote atrial fibrillation episodes in cardioembolic stroke. Conversely, the role of ANS in atrial cardiopathy and cryptogenic stroke is less known, as well as ANS effects on ECG markers of atrial dysfunction. In this paper, we review the evidence linking ANS dysfunction and atrial cardiopathy as a possible pathogenic factor in cryptogenic stroke.