Wearables fare well for AF detection

A systematic review and meta-analysis of 15 studies attest to the efficacy of single-lead electrocardiogram (ECG) smart chest patches and photoplethysmography (PPG)-based smartwatches for atrial fibrillation (AF) detection.

“Comparatively, both ECG smart chest patches and PPG smartwatches exhibited excellent performance in AF detection, with PPG smartwatches showing slightly higher sensitivity and ECG chest patches exhibiting marginally greater specificity,” said the researchers.

ECG smart chest patches demonstrated a pooled sensitivity of 96.1 percent (I²=94.5 percent) and a pooled specificity of 97.5 percent (I²=79.1 percent). For PPG smartwatches, the corresponding values were 97.4 percent (I²=3.1 percent) and 96.6 percent (I²=75.9 percent). [BMC Cardiovasc Disord 2025;25:132]

“[These results imply that] both devices showed high diagnostic performance, indicating that ECG chest patches and PPG smartwatches are equally effective tools for detecting AF,” the investigators said.

Of note, there was significant heterogeneity, potentially due to variability in demographics, reference standards for comparison, and methodologies used for AF detection. “These factors must be carefully accounted for when interpreting the results,” they noted.

Making the choice

Smartwatches may have the edge over the chest patches cost-wise, as PPG technology production is cheaper. Integrating PPG sensors into smartwatches offers broader market accessibility and affordability and is more appealing to a wider consumer base. [IEEE ISSCC 2021;doi:10.1109/ISSCC42613.2021.9365757]

Conversely, ECG chest patches are generally more expensive to produce due to the advanced sensors, sophisticated signal processing systems, and the flexible and durable patches. [Annu Int Conf IEEE Eng Med Biol Soc 2022;2022:4312-4315]

However, the patches appear to take the cake in terms of settings. “[B]y directly measuring the electrical activity of the heart, [ECG chest patches] are more suited for clinical use, particularly in patients at higher risk of atrial AF or those with pre-existing cardiovascular (CV) conditions,” they said. Moreover, the patches provide detailed and reviewable ECG waveforms, offering greater diagnostic value, especially in high-risk populations requiring comprehensive heart rhythm monitoring.

The smartwatches may be more suitable for lower-risk individuals who prefer to monitor their health in non-clinical settings. The convenience they offer facilitates personal health tracking and enables self-monitoring without the need for continuous medical supervision. [Circ Arrhythm Electrophysiol 2019;12:e006834; Heart 2020;106:665-670; J Saudi Heart Assoc 2021;33:169-176]

“Given the minimal difference in diagnostic accuracy, the choice between these wearables should consider clinical settings, cost, and practical barriers such as affordability, accessibility, and integration into healthcare systems,” said the investigators.

Going beyond the conventional route

Accurate diagnosis is vital for optimal AF management. Failure to promptly detect AF can lead to serious consequences, while overdiagnosis can lead to unnecessary interventions, including inappropriate anticoagulation therapy, which carries an increased risk of major bleeding. [J Cardiovasc Dev Dis 2023;10:458]

“Smart wearables are garnering significant attention in [this era], offering advancements beyond traditional clinical cardiac monitoring. These devices enable users to monitor their health and detect early warning signs of cardiac irregularities,” said the researchers. “[T]hese tools are poised to play a crucial role in the future of CV diagnostics.”

The analysis comprised 12,802 participants (mean age 65.89 years, 61.85 percent men). The most common gold standards used to measure sensor accuracy were 12-lead, Holter, and telemetry ECG.

“This comparative meta-analysis [provides] critical insights into the diagnostic performance of emerging wearable technologies, informing clinical practice and guiding future research in AF management,” said the researchers.

Despite their high performance, the investigators called for further evaluation of wearables to enhance accuracy, reduce false positives, and address issues such as data privacy and interoperability.

“[T]he findings could inform advancements in device design, guide manufacturers to enhance diagnostic precision and user-friendliness, and influence regulatory approvals for wearable technologies. By advancing these capabilities, wearable devices could play a pivotal role in fully digitizing AF detection and improving overall patient outcomes in cardiac care,” they concluded.