PracticeUpdate: Cardiology - Winter 2018

EDITOR’S PICKS 14

Home-BasedWearable Continuous ECGMonitoring Patch Improves the Detection of Undiagnosed Atrial Fibrillation JAMA: The Journal of the American Medical Association Take-home message • Individuals at high risk for atrial fibrillation (AF) were randomized to receive imme- diate ECG monitoring using a self-applied continuous ECG monitoring patch at home or delayed monitoring 4 months after enrollment to evaluate the effects and clinical consequences of active monitoring. In addition, a matched cohort of unmonitored controls was followed to compare the rates of AF diagnosis with the rates of those being monitored. At 4 months, AF was diagnosed in 3.9% of those undergoing immediate monitoring vs 0.9% of those receiving delayed monitoring. At 1 year, the rate of diagnosis of AF was 6.7 per 100 person-years in monitored participants vs 2.6 per 100 person-years among the unmonitored cohort. • Active monitoring was associated with increased use of anticoagulants as well as increased outpatient cardiology and primary care visits. Monitoring did not impact the rate of AF-related emergency department visits and hospitalizations. COMMENT By Samuel J. Asirvatham MD, FACC, FHRS , Deepak Padmanabhan MD and Itzhak Z. Attia MS Does Schrödinger’s Cat Have Atrial Fibrillation? T he authors of this study have very elegantly brought to light the commonly accepted clinical finding that atrial fibrillation (AF) may not always be symptomatic. Patients may have the arrhythmia without necessitating urgent medical care. In a large cohort of elderly patients at no apparent added risk of AF owing to comorbidities, there was an increase in the diagnosis of AF in those patients who were actively monitored over a continuous period, with just 2/69 (0.03%) of those patients seeking medical care for the same. In a control group consisting of patients matched for comorbidities, there was an absolute decrease of 4.5% in the diagnosis of AF at 1 year of follow-up.

were to add the skin irritation caused by the patch (1.8%) to this, a recommendation for long-term monitoring may not be easily acceptable to the population at large. This represents a niche for further innovation. In addition, as previously noted in the literature, screening for AF needs sufficient duration of continuous monitoring. Implantable loop recorders have been proven to be most sensitive for the same. 2 This could in part explain the relatively lower rates of AF detected in the monitored cohort despite 593 (IQR, 327.8–662.2) hours of monitoring per patient. Whether a strategy of continuous monitoring is superior to periodic monitoring when performed for similar durations of time is a question that arises from this study. This perhaps has economic and quality-of-life implications given current form factors available to screen for AF. There is increased healthcare service utilization in the short term for those who have been diagnosed via monitoring; however, the duration of follow-up is not adequate to ascertain its long-term benefit. Form factor research is critical for widespread accept- ance and a role for wellness monitoring could exist in being able to provide primordial prevention of contributory factors. Utility in higher-risk groups, such as those with valvular heart disease and hypertrophic cardiomyopathy, remains unknown; but, given its incidence in apparently healthy individuals, it is not unlikely that there may be a higher incidence of asymptomatic AF. A smaller potentially hypothesis-generating finding was the detec- tion of additional actionable arrhythmias during the monitoring

This study validates the Class I recommendation that the Euro- pean Society of Cardiology has given for the screening of AF in those patients at risk. 1 Despite the median burden of AF detected being 0.9%, it is critical to initiate anticoagulation in these patients. Therein lies the importance of detecting the arrhythmia. Although rhythm control may cater to improving the quality of life in these patients, anticoagulation could prevent a disastrous neurological event. This remains an intuitive conclusion, one which this study aims to provide at the end of 3 years’ follow-up. The study was limited in part by the fact that 33% of patients who were prescribed the patch did not wear it at all, and 25% of the patients who did use the patch, wore it for only 14 days, allow- ing only half of the monitoring time. This indicates that perhaps the form factor for the monitoring was not conducive to long- term monitoring, or that more patient education is needed. If one

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