Device monitoring allows more defined AF classifications

Using data derived from patient monitoring devices, researchers found clearer, more reproducible results on burden and persistence in atrial fibrillation (AF) patients than through clinical observations alone.

In a study published July 1 in the Journal of the American College of Cardiology, researchers explored the definitions applied to the degree of AF present in patients from a clinician observation against device-derived classifications. As AF classification is generally the standard by which treatment is determined for the patient, the research team focused on determining how best to classify patients, in order to provide them with the most optimal outcomes.

The team of researchers from Germany, Austria, New Jersey and Minnesota utilized data from the previously published OMNI and TRENDS studies. They found that AF classifications derived from clinician observation showed considerable overlap in their symptoms between differing groups, while device-derived classification had clear delineation between groups.

Among the patients who were clinically classified as paroxysmal, 34.5 percent of patients did not experience any AF symptoms during the observation period, as did 21.2 percent of patients classified as persistent. Two percent of clinically paroxysmal patients and 13.4 percent of clinically persistent AF patients presented with continuous AF during their observation period. Meanwhile, those classifications derived from the patients’ long-term device feed remained consistent throughout.

Efstratios I. Charitos, MD, from the University of Lubeck’s Department of Cardiac and Thoracic Vascular Surgery in Germany, and colleagues proposed that significant therapeutic possibilities may be derived from use of clearer device-derived data. They wrote, “A potential explanation for lack of complete efficacy with the pulmonary vein isolation only approach is that some of the patients perceived to have paroxysmal AF may actually have a more persistent form of the disease.”

At this point, the data are inclusive of only those individuals whose AF was clinically severe enough to warrant an implantable device with external leads. But newer, more streamlined devices are currently on the market and provide wireless, remote data linkable to EHR and electrocardiographic smartphone apps also exist for daily reporting. Suneet Mittal, MD, of Valley Hospital’s Electrophysiology Laboratory in Ridgewood, N.J. ,suggested both options in an editorial.

He remarked that patients undergoing implantation of a device may not best represent all AF patients. “Nonetheless, the authors are correct in stating that clinical decisions (rate vs. rhythm control; antiarrhythmic medications vs. catheter ablation; choice of lesion sets during ablation) are routinely being made based on clinical classifications of the temporal persistence of AF, which appear to have limited accuracy.”

OMNI Study–Assessing Therapies in Medtronic Pacemaker, Defibrillator, and Cardiac Resynchronization Therapy Devices utilized only one specific device. TRENDS: A Prospective Study of the Clinical Significance of Atrial Arrhythmias Detected by Implanted Device Diagnostics, looked at a wider range of devices. The studies were sponsored by Medtronic.