Introduction: Clinical atrial fibrillation (AF) classifications are important for patient management
and design of clinical trials. However, the ability of the physician to accurately
classify the intensity of AF is unknown. The aim of the present study was to investigate
how accurately a physician can evaluate a patient's AF classification in patients
continuously monitored with implantable devices.
Methods: Cardiac rhythm histories of 1,195 patients (age 73.0 ± 10.1 years, follow-up: 349 ± 40
days) with implantable devices were reconstructed and analyzed. Patients were classified
as having paroxysmal or persistent AF by physicians at baseline in accordance with
current guidelines. After the end of the study we measured the device registered AF
burden as the proportion of time spent in AF. For the purposes of this study, 258
patients with more than 300 days of recorded data and more than 5% AF burden recurrence
were included in the present study.
Results: A significant misclassification between clinical and device related data occurred
(Cohen's kappa 0.06 95%C.I. [0.02–0.11]). The clinical AF classification agreed with
the device AF classification only in 35.6% of patients. 7% of patients who experienced
paroxysmal AF (device data AF burden 0.17[0.08–0.23] median[IQR]) were instead clinically
classified as having persistent AF. On the contrary 80% of patients who experienced
documented persistent AF (device data AF burden 0.49[0.21–0.89]) were instead classified
as having clinical paroxysmal AF.
Conclusion: Our data show that physicians misclassify AF in the vast majority of cases. This
misclassification occurs in low and high AF burden spectra; however, it seems to be
more pronounced in mid to high AF burden spectra. 80% of patients who experienced
persistent AF were instead classified by physicians as having paroxysmal AF. This
has important implications for patient management and design of clinical studies.
