Incidence and Clinical Significance of New-Onset Device-Detected Atrial Tachyarrhythmia: A Meta-Analysis.

Background: Despite the clear association between atrial fibrillation and risk for thromboembolic events (TEs), the clinical significance of new-onset device-detected atrial tachyarrhythmia (DDAT) and TE remains disputed. We aimed to determine the risk of TE in patients with new-onset DDAT.

Methods And Results: The OVID Medline, Cochrane, and Scopus databases (inception to November 2016) were searched. Randomized controlled trials, prospective, or retrospective studies of pacemaker or defibrillator patients reporting incidence of DDAT were selected. Summary statistics were used for analysis. Of 4893 reports identified, 28 studies following 24 984 patients were included: average age 69.9 years, 34.7% women, mean study duration 21.8±18.6 months. New-onset DDAT was observed in 23% of patients. Among 9 studies (n=8181) reporting TE, the absolute incidence was 2.1%. TE risk was significantly greater among patients with new-onset DDAT (relative risk [RR], 2.88; 95% CI, 1.79-4.64; <0.001). TE risk was correlated with DDAT duration, with an increased risk associated with DDAT ≥5 minutes (RR, 3.86; 95% CI, 2.04-7.30; <0.001) compared with <1 minute (RR, 1.77; 95% CI, 1.15-2.74; =0.01). Notably, the risk of TE was also increased in patients with adjudicated atrial electrograms (RR, 3.60; 95% CI, 2.06-6.30; <0.001) compared with nonadjudicated electrograms (RR, 2.05; 95% CI, 1.06-3.97; =0.03), even when lower mean thresholds for detection were used.

Conclusions: New-onset DDAT is common, affecting close to one quarter of all patients with implanted pacemakers or defibrillators. Adjudication of atrial electrograms further identifies at-risk patients, even when relatively short detection thresholds are used.