Stroke incidence in patients with cardiac implantable electronic devices remotely controlled with automatic alerts of atrial fibrillation. A sub-analysis of the HomeGuide study

BackgroundRemote Monitoring (RM) of cardiac implantable electronic devices (CIEDs) is recommended in management of Atrial Fibrillation (AF), which is a recognized risk factor for thromboembolism. We tried to elucidate whether stroke incidence observed in a large, remotely monitored population was consistent with the CHA2DS2VASc risk profile.MethodsData from 1650 patients [76% male, age 72 (63–68), CHA2DS2VASc score 3.0 (2.0–4.0)] enrolled during the HomeGuide study and monitored with a daily-transmission RM system providing automatic alerts for AF, were analysed. Of those, 25% had a pacemaker and 75% an implantable cardioverter defibrillator with or without cardiac resynchronization. Estimations of the expected thromboembolic events were based on the population CHA2DS2VASc score profile used in a computer-simulated Markov model.ResultsEight thromboembolic events were observed with a 4-year cumulative stroke rate of 0.8% (confidence interval, 0.4%–1.5%). Simulations returned from 18.7 to 17.1 expected events, depending on the AF duration assumed to trigger anticoagulation (one-sample log-rank p < 0.03). During the study period, 681 (84%) AF episodes and 129 (16%) atrial tachycardias were detected in 291 patients (18%): 93% of episodes were detected remotely in 269 patients, 66% of whom had no history of AF. Medical interventions were necessary in 305 episodes, 85% of which were detected remotely. Reaction time was 1 (0–6) days for remotely-detected episodes and 33 (14–121) days for episodes detected in clinic (p < 0.0001).ConclusionsIn a large CIED population followed remotely for up to 4 years, the incidence of thromboembolic events was less than half the estimations based on the CHA2DS2VASc risk profile.