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

BackgroundIn patients with a history of stroke or those at high risk of developing stroke, a continuous rhythm monitoring strategy using implantable loop recorders (ILR) is often performed to screen for atrial fibrillation (AF). ObjectivesWe performed a systematic review (MEDLINE and EMBASE) including randomized controlled trials comparing ILR-based continuous rhythm monitoring versus usual care in patients with a history of stroke or patients at high risk of developing stroke. MethodsA meta-analysis was performed and aggregate risk ratios (RR) and risk difference (RD) with their 95% confidence intervals were calculated. ResultsFour randomized controlled trials with 7,237 patients (ILR=2,114 and non-ILR=5,123) were included. ILR vs. non-ILR was associated with increased detection of incident AF (RR 3.88; 95% CI [2.23 - 6.75]; p<0.00001; NNT=7.7, I2=61%), increased appropriate initiation of anticoagulation (RR 2.29; 95% CI [2.07 - 2.55]; p<0.00001; NNT=6.7, I2=0), and a 25% lower risk of developing stroke (RR 0.75; 95% CI [0.59 – 0.95]; p=0.02; 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=0.25; I2=0%). ConclusionOur meta-analysis shows that screening for AF with ILR is associated with increased detection of AF, and increased initiation of appropriate anticoagulation 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.