Effect of implantable loop recorder-based continuous rhythm monitoring on incident atrial fibrillation and stroke: An updated systematic review and meta-analysis of randomized controlled trials

Abstract

Background: In patients with a history of stroke or those at high risk for developing stroke, a continuous rhythm monitoring strategy using an implantable loop recorder (ILR) is often performed to screen for atrial fibrillation (AF).

Objectives: The purpose of this study was to perform a systematic review (MEDLINE and EMBASE) including randomized controlled trials comparing ILR-based continuous rhythm monitoring vs usual care in patients with a history of stroke or patients at high risk for developing stroke.

Methods: A meta-analysis was performed, and aggregate risk ratio (RR) and risk difference (RD) with 95% confidence interval (CI) were calculated.

Results: Four randomized controlled trials with 7237 patients (ILR 2114, non-ILR 5123) were included. ILR vs non-ILR was associated with increased detection of incident AF (RR 3.88; 95% CI 2.23-6.75; P <.00001; number needed to treat [NNT] = 7.7; I² = 61%), increased appropriate initiation of anticoagulation (RR 2.29; 95% CI 2.07-2.55; P <.00001; NNT = 6.7; I² = 0), and a 25% lower risk of developing stroke (RR 0.75; 95% CI 0.59-0.95]; P = .02; NNT = 100; I2 = 0%). In patients with history of stroke there was no difference in the risk of developing incident stroke (RR 0.83; 95% CI 0.61-1.14]; P = .25; I2 = 0%).

Conclusion: Our meta-analysis showed that screening for AF with ILR is associated with increased detection of AF and increased initiation of appropriate anticoagulation therapy in patients with a history of stroke or those with risk factors for stroke. The benefit of stroke risk reduction with ILR remains unclear, and future studies focused on the inclusion of patients without a history of stroke are needed to elucidate this uncertainty.

Keywords: Implantable loop recorder; Meta-analysis; Screening; Stroke; atrial fibrillation.