Atrial Speckle Tracking Echocardiography for Detecting Atrial Fibrillation in Cryptogenic Stroke: A Meta-Analysis

Cryptogenic stroke (CS) accounts for approximately 25% of ischemic stroke cases, with atrial fibrillation (AF) accounting for 30% of CS cases. We investigated the utility of left atrial (LA) speckle-tracking echocardiography in identifying patients at high risk of AF after CS and potentially guiding patients who will benefit from long-term rhythm monitoring devices. Cochrane Library, MEDLINE, and EMBASE were searched for relevant studies. We included studies that examined patients with new CS without a history of AF and further examined LA strain parameters (peak and/or reservoir strain). Continuous data were pooled as a mean difference (MD) comparing patients who developed AF vs no AF.  We used the inverse variance method with the DerSimonian-Laird estimator for tau2 and Hartung-Knapp adjustment for random effect analysis. I² was used to assess heterogeneity. Thirteen observational studies met our criteria and included 3031 patients with new CS. Of those, 420 patients developed AF on follow-up, and 2611 patients did not develop AF. The AF group vs. no AF had significantly reduced LA reservoir strain (LARS) [MD: -8.61; 95% CI: -10.76, -6.47, I2 = 85%, p < 0.01] at presentation. LARS is significantly lower in patients who developed AF after CS. More studies are needed to validate this data.