Background: Electrocardiography (ECG) stands as the gold standard for the evaluation of cardiac arrhythmias. Recent smartwatches aim to promptly detect rhythm abnormalities enhancing user experience. However, the accuracy of these devices remains controversial. Our purpose was to perform a systematic review and meta-analysis evaluating the diagnostic performance of the Apple Watch electrocardiogram in detecting atrial fibrillation (AF). Methods: The literature search was conducted on PubMed, Embase, and Cochrane through April, 2024 for studies comparing the diagnostic accuracy of Apple Watch to standard 12 Lead ECG. Statistical analysis was performed using R Software version 4.4.0. Pooled analyses of sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) were determined along with their 95% confidence intervals (CI). The quality of studies was analyzed using the QUADAS-2 tool. Results: The meta-analysis included 11 studies comprising 13,490 participants. Their mean age was 62.56 ± 3.92 years and 28% of the population were females. The pooled sensitivity and specificity of Apple Watch for detecting AF was 94.8% (95% CI 91.7 - 96.8%) and 95% (95% CI 88.6 - 97.8%) respectively. The AUC was 0.96 (95% CI 0.92 - 0.97; Figure 1). Sensitivity analysis for heterogeneity revealed no significant change in values for sensitivity 94.8% (95% CI 91.7-96.8%) and specificity 94.9% (95% CI 88.6-97.8%). The studies had a low risk of bias in Index test and reference standard domains, but a high risk of bias in patient selection and Flow and timing domains. Conclusion: The Apple Watch ECG shows a high accuracy in detecting atrial fibrillation, providing a convenient and timely option for such patients.
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