Reduced left atrial strain and risk of ischemic stroke in patients with normal sinus rhythm: a systematic review and meta-analysis

ABSTRACT

INTRODUCTION: Abnormalities in the left atrium have been linked to a higher risk of ischemic cerebrovascular events. Left atrial (LA) strain analysis can identify LA dysfunction, even in patients with normal LA volumes. However, the precise association between LA strain and the occurrence of ischemic stroke in individuals who are in normal sinus rhythm (NSR) is not well established. Hypothesis: This systematic review and meta-analysis aimed to assess the relationship between reduced LA strain and the risk of ischemic stroke in patients with NSR. METHODS: We searched PubMed, Embase, and Cochrane Central for studies that examined our clinical question. Two reviewers independently performed study selection, data extraction, and assessment of bias. Statistical analysis was performed using Review Manager 5.4.1. Heterogeneity was assessed with I2 statistics. We calculated pooled multivariable-adjusted hazard ratios (HR) with 95% confidence intervals (CI) under a random effects model. RESULTS: We included 8,632 patients from 4 cohort studies, of which 3 were prospective. The mean follow-up ranged from 2.5 years to 10.9 years. The mean age ranged from 68.8 to 75.2 years. All results were obtained through multivariable-adjusted analysis, which includes adjusting for LA size and occurrence of new-onset atrial fibrillation during follow-up. The incidence of ischemic stroke was significantly increased in patients with reduced reservoir strain (HR 1.53; 95% CI 1.09-2.15; p=0.01; Figure 1) and conduit strain (HR 1.39; 95% CI 1.16-1.59; p < 0.001). Reduced contractile strain was not predictive of stroke incidence (HR 1.94; 95% CI 0.96-3.93; p=0.07). CONCLUSIONS: Our findings indicate an independent association of reduced LA strain with an increased incidence of ischemic stroke in patients without a previous history of atrial fibrillation. Future studies are warranted to evaluate the role of LA strain as part of a comprehensive risk stratification for stroke.