7-day Holter Monitoring in Adult Patients With Recent IS or TIA, to Measure the Prevalence of Paroxysmal Atrial Fibrillation Including Episodes Less Than 30 Seconds: Transversal Study

Rational:

Although patient management and treatment has greatly improved in recent years, atrial fibrillation (AF) remains the most common arrhythmia related with stroke, heart failure, sudden death and cardiovascular morbidity in the global population1. Considering the general adult population, the prevalence of AF is less than 1%, while in people aged 75-84 it reaches 7%2,3, and is expected to increase in the elderly population and in patients with certain predisposing risk factors4-10. Recent studies show that 20-30% of stroke survivors are likely related to AF11-14 and, if not treated properly, it can lead to serious consequences such as future thromboembolic complications, recurrence of stroke episodes or death15-17. The UK National Clinical Guidelines for Stroke Patient Management, provided by the Royal College of Physicians18, recommend cardiac monitoring for at least 12 hours for people with IS or TIA who would be eligible for secondary prevention treatment for AF and at least 24 hours for monitoring for patients with no other known cause of stroke.

The 2016 ESC guidelines for the treatment of AF instead recommend monitoring of at least 72 hours in patients with IS or TIA, for example 72 hours of Holter monitoring after the stroke event12,19, or for longer periods20,21. Given the intermittent nature of AF and its inclination to be asymptomatic, it would be useful to test the hypothesis that this last approach could lead to a better diagnosis strategy of AF and consequently could clarify the relationship between AF and stroke.

Detection of AF episodes has improved with the rapid development of technology in the medical field, and recently there has been an increase in interest in evaluating whether brief atrial fibrillation (BAF) episodes, less than 30 seconds, carry a similar risk to those of greater length and whether these constitute an indication for treatment. Although new research is focusing on detecting BAF episodes, uncertainty persists in determining whether or not these episodes increase the risk of stroke, as well as the treatment needed for the aforementioned range of patients.

A recent study in patients with first episode of IS or TIA and presence of AF detected by standard ECG concluded that in 6.3% of 869 cases AF was paroxysmal22. The definition of paroxysmal atrial fibrillation (PA AF) in this specific case was related to those episodes of AF that spontaneously converted into sinus rhythm. Similarly, in another study from 2010, previously undiagnosed PA AF was found in 9.2% of the population with IS or TIA23; in the latter study, the mean monitoring time was 22.6 hours and the presence of only episodes of BAF was detected in 72% of the people diagnosed with PA AF while the rest of the patients also had longer episodes of 30 seconds. Similar results were obtained in an AF study in the population with IS or TIA after mobile cardiac telemetry in which 85% of device-reported episodes were found to be less than 30 seconds24. These results encourage researchers to focus more on the subject, therefore in this study we want to investigate the real prevalence of BAF. The results could guide clinicians to determine the most appropriate preventive and curative interventions for this group of patients.