LCDR John C. Chin, MD, MC, USNa; CAPT Andrew H. Lin, MD, MC, USNa; Nicholas M. Sicignano, MPHb; Toni M. Rush, PhD, MPHb
Correspondence: John Chin (chinjoh@gmail.com)
aNaval Medical Center Portsmouth, Virginia
bHealth ResearchTx LLC, Trevose, Pennsylvania
Author disclosures
The authors report no actual or potential conflicts of interest or outside sources of funding with regard to this article.
Disclaimer
The opinions expressed herein are those of the authors and do not necessarily reflect those of Federal Practitioner, Frontline Medical Communications Inc., the US Government, or any of its agencies.
Ethics and consent
Research and data from this study were reviewed andapproved by the Naval Medical Center PortsmouthInstitutional Review Board.
As a retrospective study and without access to the National Death Index, we were unable to determine the exact cause or events leading to death and instead utilized all-cause mortality data. Subsequently, our observations may only demonstrate association, rather than causality, between AF/AFL and death in patients with WPW syndrome. Additionally, we could not distinguish between AF and AFL as the arrhythmia leading to death. However, since overall survivability was the outcome of interest, our adjusted HR models were still able to demonstrate the increased association of the composite outcome and death within an AF/AFL cohort.
Although a large cohort was analyzed, due to the constraints of utilizing diagnostic codes to determine study outcomes, we could not distinguish between symptomatic and asymptomatic patients, nor how they were managed prior to the outcome event. However, as recent literature demonstrates, updated predictors of malignant arrhythmia and decisions for early EPT are similar for both symptomatic and asymptomatic patients and should be driven by the intrinsic electrophysiologic properties of the accessory pathway, rather than symptomatology;thus, our inability to discern this should have negligible consequence in determining when to perform risk stratification and ablation.1
MHS eligible patients have direct access to care; the generalizability of our data may not necessarily correspond to a community population with lower socioeconomic status (we did adjust for military sponsor rank which has been used as a proxy), reduced access to care, or uninsured individuals. However, the prevalence of WPW syndrome within our cohort was comparable to the general population, 0.4% vs 0.1%-0.3%, respectively.13,14,19 Similarly, the incidence of AF within our population was comparable to the general population, 15% vs 16%-26%, respectively.23 These similar data points suggest our results may apply beyond MHS patients.
CONCLUSIONS
Patients with WPW syndrome and AF/AFL have a higher association with adverse cardiac outcomes and death. Despite previously reported low SCD incidence rates in this population, our study demonstrates the increased association of mortality in an AF/AFL cohort. The limitations of utilizing all-cause mortality data necessitate further investigation into the etiology behind the deaths in our study population. Since ventricular pre-excitation can predispose patients to AF and potentially lead to malignant arrhythmia and SCD, understanding the cause of mortality will allow physicians to determine the appropriate monitoring and intervention strategies to improve outcomes in this population. Our results suggest consideration for more aggressive EPT screening and ablation recommendations in patients with WPW syndrome may be warranted.
