Author + information
- Kevin J. Um,
- Emilie P. Belley-Côté, MD,
- Jeff S. Healey, MD, MSc∗ ( and )
- William F. McIntyre, MD
- ↵∗Department of Medicine, McMaster University, David Braley Cardiac, Vascular, and Stroke Research Institute, Suite C3-121, 237 Barton Street East, Hamilton, Ontario L8L 2X2, Canada
The management of “secondary” atrial fibrillation (AF) is unclear (1). When AF is detected as a secondary diagnosis during hospitalization for another condition, it may be a temporary phenomenon that does not recur after the precipitating stressor is removed. Alternatively, it may be the first diagnosis of paroxysmal AF. A better understanding of “secondary” AF is necessary to determine whether clinicians should prescribe oral anticoagulation (OAC) for stroke prevention.
On the basis of their analysis of administrative data, Quon et al. (2) suggest that there is no clear benefit to using OAC in patients with “secondary” AF. However, there are several limitations with their analysis. The ascertainment of AF prevalence using administrative data has low sensitivity, even when validated algorithms are used (3). More specifically, the detection by Quon et al. (2) of “secondary” AF during hospitalization also appears insensitive because they identify 102 patients with sepsis and secondary AF over a 17-year period in Quebec (∼8 million residents). This number is much lower than would be expected based on prior studies (4). Finally, the assessment of the effects of OAC on patients with “secondary” AF is subject to many confounders. Patient- and physician-related factors that determine the risk of stroke and other adverse outcomes are also associated with the decision to prescribe OAC after “secondary” AF. Multivariable adjustment can only partially correct for imbalances in these factors, and such correction is never complete. Considering these limitations, one should be cautious in assuming that OAC does not afford benefit in this setting. Randomized controlled trials (RCTs) have demonstrated marked benefit from OAC, and another observational study in this “secondary” AF group demonstrated benefit from OAC (adjusted hazard ratio: 0.59; 95% confidence interval: 0.40 to 0.86) (5).
Our group has proposed atrial fibrillation occurring transiently with stress (AFOTS) as a more accurate term for describing “secondary” AF (1). The term “secondary” implies clinical certainty that AF will not return once the stressor (e.g., sepsis, acute lung disease) is removed. An RCT of OAC in these patients would be the most definitive way to address the management of AFOTS. Without such an RCT, the demonstration of AF recurrence after hospitalization in a high proportion of patients with AFOTS would suggest that AFOTS may simply represent the first detection of typical clinical AF. In retrospective studies with low-sensitivity detection methods (i.e., 12-lead electrocardiograms and short-duration ambulatory monitors), up to 50% of patients with AFOTS have AF recurrence within 1 year (1). Our ongoing multicenter study (AFOTS [Atrial Fibrillation Occurring Transiently With Stress]; NCT03221777) is designed to demonstrate this finding with a high-sensitivity detection method and will be the first step in defining an optimal management strategy for AFOTS.
We agree with Quon et al. (2) that in the absence of RCT data, clinicians must carefully evaluate the risks and benefits of OAC for “secondary” AF. In fact, the risks and benefits may be partly stressor dependent. The increased bleeding risk in post–acute coronary syndrome patients who require antiplatelet therapy may outweigh any potential benefit in stroke prophylaxis. Conversely, in septic patients with multiple comorbidities not requiring antiplatelet therapy, stroke prophylaxis benefit may significantly outweigh the increased bleeding risk.
Please note: The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
All authors attest they are in compliance with human studies committees and animal welfare regulations of the authors’ institutions and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the JACC: Clinical Electrophysiology author instructions page.
- 2018 American College of Cardiology Foundation
- McIntyre W.F.,
- Connolly S.J.,
- Healey J.S.
- Quon M.,
- Behlouli H.,
- Pilote L.
- Cheng C.A.,
- Cheng C.G.,
- Lin H.C.,
- et al.