Application of wearable photoplethysmography- electrocardiogram monitor (HC3A250) in monitoring paroxysmal atrial fibrillation after mechanical thrombectomy for acute ischemic stroke

Technical Summary: Application of Wearable HC3A250 in Post-Thrombectomy Stroke Monitoring

Problem Statement
Acute ischemic stroke (AIS) patients, particularly those undergoing mechanical thrombectomy (MT), face a significant risk of paroxysmal atrial fibrillation (pAF). While pAF is a major modifiable risk factor for recurrent stroke, its detection remains challenging. Standard 12-lead ECGs and 24-hour Holter monitors often miss transient episodes, identifying pAF in only 2–5% of cases via Holter. Furthermore, existing portable solutions like single-lead smartwatches lack the multi-lead support necessary for complex arrhythmia analysis, while traditional patches may be cumbersome for long-term or intermittent monitoring. There is a critical need for a device that balances the portability of wearables with the diagnostic fidelity of multi-lead ECGs to effectively screen for pAF in the post-stroke population.

Methodology
This study employed a two-stage design to evaluate the HC3A250, a wearable photoplethysmography-electrocardiogram (PECG) monitor featuring four eccentric electrodes and 3-lead recording capabilities.

• Stage 1: Feasibility and Reliability Verification

  • Subjects: 128 hospitalized patients with sinus rhythm (aged >22) were recruited.
  • Protocol: Patients underwent simultaneous recording using a standard 12-lead ECG (Nalong RAGE-12) and the HC3A250. The HC3A250 was placed according to the Einthoven triangle principle to capture M(I), M(II), and M(avF) signals.
  • Analysis: The study compared waveform intervals (P wave, PR, QRS, QT, T wave) and heart rate between the two devices. Statistical evaluation included Bland-Altman analysis for agreement, Concordance Correlation Coefficients (CCC) for consistency, and Spearman correlation for monotonic relationships.

• Stage 2: Clinical Application in Post-Thrombectomy Monitoring

  • Subjects: 116 AIS patients were divided into an observation group (n=58, underwent MT) and a control group (n=58, did not undergo MT). All patients had no prior history of AF.
  • Protocol: The HC3A250 was used for continuous 24-hour ambulatory monitoring immediately after admission.
  • Analysis: The study assessed the detection rate of pAF (defined as episodes >30 seconds) in both groups. It further analyzed correlations between pAF occurrence and specific stroke vascular territories (e.g., anterior cerebral artery) and stroke regions. Multivariate logistic regression was used to adjust for confounders such as age, gender, and NIHSS scores.

Key Contributions

• Device Validation: The study provides quantitative evidence that the HC3A250, a 3-lead wearable device, achieves high consistency with the gold-standard 12-lead ECG for critical waveform intervals.
• Clinical Application: It explores the utility of this specific wearable technology in the specific context of post-MT stroke monitoring, addressing the gap between consumer-grade wearables and clinical diagnostic tools.
• Vascular-Arrhythmia Correlation: The research investigates the potential link between specific vascular occlusions (particularly anterior cerebral artery involvement) and the development of pAF following MT, offering preliminary data on neurogenic mechanisms.

Results

• Reliability (Stage 1):

  • Heart Rate: The devices showed a mean deviation of -0.415 ms with a CCC of 0.9319 and a Spearman coefficient of 0.919, indicating extremely strong correlation.
  • Waveform Intervals: The HC3A250 demonstrated "good" to "excellent" consistency (CCC > 0.95) for P wave, PR interval, QRS complex, and QT interval when compared to leads I, II, and avF of the standard ECG.
  • T-Wave: While T-wave measurement showed moderate consistency (CCC = 0.9117), all other parameters met the threshold for good consistency.
  • Bland-Altman: Data points were evenly distributed around the zero line with narrow limits of agreement (LoA), suggesting no proportional bias.

• Clinical Detection (Stage 2):

  • Detection Rates: Unadjusted analysis revealed a higher pAF detection rate in the MT group (17.2%) compared to the control group (5.2%). However, this difference lost statistical significance after adjusting for confounding factors via multivariate logistic regression.
  • Vascular Correlation: Among MT patients, those with pAF showed a statistically significant association with anterior cerebral artery (ACA) involvement compared to non-pAF patients. No significant correlations were found for the internal carotid, middle cerebral, or vertebrobasilar systems.
  • Prognosis: At 90 days post-discharge, patients with detected pAF had a higher rate of poor prognosis (80%) compared to those without pAF (66.7%), though the difference in mRS score improvement was not statistically significant.

Significance and Claims
The authors conclude that the HC3A250 demonstrates good consistency with standard 12-lead ECGs regarding waveform intervals, validating its potential as a rapid, short-term screening tool for post-stroke atrial fibrillation. The device's ability to accurately capture P-wave morphology is highlighted as a crucial technical advantage for diagnosing atrial arrhythmias, positioning it as a viable alternative to single-lead consumer devices and a more portable option than traditional Holter monitors.

However, the paper maintains a modest stance regarding its clinical findings. The authors explicitly state that the observed association between mechanical thrombectomy and pAF requires further validation in larger cohorts with longer monitoring periods. They acknowledge limitations, including the small sample size for subgroup analysis (specifically regarding ACA involvement) and the inability to definitively test the device's automatic AF detection algorithm in a dedicated AF cohort. Consequently, the study positions the HC3A250 as a promising tool for initial screening and monitoring, while emphasizing the need for senior ECG specialist interpretation and further research to confirm its diagnostic sensitivity and specificity in diverse arrhythmia populations.