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Canadian Journal of Cardiology

STROKE RISK AND ORAL ANTICOAGULATION USE WITH EXTENDED CARDIAC MONITORING FOR ATRIAL FIBRILLATION VERSUS USUAL CARE: A SYSTEMATIC REVIEW AND META-ANALYSIS

      Background

      Extended cardiac monitoring is used to detect atrial fibrillation (AF) in high-risk populations, including those with a history of cryptogenic stroke. Despite demonstrated effectiveness in AF detection, randomized trials have not clearly demonstrated a reduction in stroke and systemic embolism (SSE) or transient ischemic attack (TIA). We performed a systematic review and meta-analysis of randomized trials evaluating extended monitoring versus usual care on reduction of stroke/SSE and TIA (PROSPERO #CRD42021277611).

      Methods and Results

      Studies were identified through CENTRAL, MEDLINE, and Embase searches using “atrial fibrillation” and separate terms for all monitoring devices. We included studies with ≥100 participants and ≥30 days follow-up. The primary outcome was a composite of SSE/TIA (or most inclusive outcome reported), with secondary outcomes including: AF incidence, oral anticoagulation (OAC) initiation, major bleeding, and adverse events. Meta-analyses were performed using R ‘meta’ package reporting risk ratios (RR) with 95% confidence intervals (95% CI) using a random-effects model. Risk-of-bias assessments were performed using the Cochrane Risk of Bias (RoB2) tool. From 1411 records, we included 9 RCTs (n=10,205). Mean age of was 69.5 years, 40.4% were female, and mean CHADS2 score was 4.0. Four studies used implantable cardiac monitors, 3 used external cardiac monitors, and 2 used handheld ECG devices (Table 1). Study populations included post-stroke or embolic stroke of undetermined significance (n=5), risk factors for AF or stroke (n=2), and post-cardiac surgery (n=1). Mean follow-up was 15.7 months (range 3.0-64.5). All studies had a low risk of bias or some concerns across most domains . Extended monitoring did not significantly reduce the primary outcome (Figure 1, RR 0.87, 95% CI 0.72-1.04, I2=0%, moderate certainty), or its individual components, versus usual care. Extended monitoring increased AF detection (RR 4.56, 95% CI 3.01-6.92, I2=65%, high certainty) and OAC use (RR 2.25, 95% CI 2.01-2.53, I2=0%, high certainty), but not major bleeding (RR 1.23, 95% CI 0.84-1.82, I2=0%, low certainty) or adverse events (RR 0.93, 95% CI 0.68-1.27, 1 trial, very low certainty).

      Conclusion

      In this meta-analysis of RCTs, extended monitoring was associated with increased AF detection and OAC use. However, it remains unclear whether extended monitoring is associated with a reduced risk of thromboembolic events.
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