Elsevier

Heart Rhythm

Volume 13, Issue 1, January 2016, Pages 3-9
Heart Rhythm

Secondhand smoke and atrial fibrillation: Data from the Health eHeart Study

https://doi.org/10.1016/j.hrthm.2015.08.004Get rights and content

Background

Cigarette smoking is a risk factor for atrial fibrillation (AF), but whether secondhand smoke (SHS) impacts the risk of AF remains unknown.

Objective

To determine if SHS exposure is associated with an increased risk of AF.

Methods

We performed a cross-sectional analysis of data from participants enrolled in the Health eHeart Study, an internet-based, longitudinal cardiovascular cohort study, who completed baseline SHS exposure and medical conditions questionnaires. SHS was assessed through a validated 22-question survey, and prevalent AF was assessed by self-report, with validation of a subset (n = 42) by review of electronic medical records.

Results

Of 4976 participants, 593 (11.9%) reported having AF. In unadjusted analyses, patients with AF were more likely to have been exposed to SHS in utero, as a child, as an adult, at home, and at work. After multivariable adjustment for potential confounders, having had a smoking parent during gestational development (OR 1.37, 95% CI 1.08–1.73, P = .009) and residing with a smoker during childhood (OR 1.40, 95% CI 1.10–1.79, P = .007) were each significantly associated with AF. Both positive associations were more pronounced among patients without risk factors for AF (P values for interaction <.05).

Conclusions

SHS exposure during gestational development and during childhood was associated with having AF later in life. This association was even stronger in the absence of established risk factors for AF. Our findings indicate that SHS in early life may be an important, potentially modifiable risk factor for the development of AF.

Introduction

Atrial fibrillation (AF) affects millions of Americans and is growing in incidence and prevalence.1 It nearly doubles mortality and is one of the most common causes of stroke.2, 3 Though the mechanism of AF remains largely unknown, observational analyses have identified age, male sex, white race, hypertension (HTN), heart failure, diabetes, obesity, and alcohol consumption as risk factors for AF.4, 5 An emerging risk factor for AF is cigarette smoking, which has been linked to the development of AF in both current and former smokers.6, 7

Though no studies have been published examining the effect of secondhand smoke (SHS) on AF, SHS exposure is associated with increased cardiovascular disease and mortality.8 It is estimated that SHS exposure increases nonsmokers’ coronary artery disease (CAD) risk by 25%–30%,9 and the vast majority of deaths in the United States attributed to SHS are from heart disease.10 Protection from SHS through the implementation of smoke-free legislation is rapidly followed by reductions in hospital admissions for acute myocardial infarctions, stroke, and other cardiac events.11, 12, 13 Despite progress in reducing smoking prevalence and the resultant SHS exposure, SHS remains a significant hazard in the United States and worldwide.14 Current hypotheses regarding the mechanism by which SHS leads to cardiac disease include induction of an inflammatory state,15 direct effects of nicotine on atrial structural remodeling,16, 17 and effects on autonomic function.18, 19 Each of these mechanisms has also been implicated in the pathogenesis of AF.4, 20

Up to 30% of all AF occurs in patients without any clear risk factors.21 While some “lone AF” patients may have an inherited component, the majority do not,22, 23 suggesting that some as-yet-unknown environmental exposure may be important. Given the increasing burden of AF and the need to identify effective prevention strategies, we examined the possible relationship between SHS exposure and the prevalence of AF, hypothesizing that SHS exposure increases the risk of AF.

Section snippets

Study design

We performed a cross-sectional analysis of data obtained between March 8, 2013 (enrollment initiation) and November 13, 2014 from consecutive participants enrolled in the Health eHeart Study. The Health eHeart Study is an internet-based, longitudinal, cardiovascular cohort study.

English-speaking adults worldwide with a working e-mail address were eligible for participation. Participants were recruited from the University of California, San Francisco (UCSF) cardiology and general medicine

Results

At the time of this analysis, there were 6863 participants enrolled in the study, of whom 4976 had completed the baseline SHS exposure and medical conditions questionnaires. Of these participants, 593 (11.9%) reported having AF, of whom 271 (45.7%) reported persistent AF and 275 (46.4%) reported paroxysmal AF. Of the 42 Health eHeart participants with medical records at UCSF who provided electronic HIPAA consent, 25 indicated having AF. Of those, 100% had AF documented by a physician in their

Discussion

We found that SHS, particularly when present during development and early childhood, was statistically significantly associated with the presence of AF. This relationship was particularly strong in the absence of known AF risk factors, suggesting a direct connection between SHS in early life and AF pathophysiology.

Past research on tobacco and AF has focused on the effects of active smoking, providing the foundation for the hypothesis tested in the current study. The Rotterdam Study, a

Conclusions

In our study of nearly 5000 Health eHeart participants, SHS exposure during gestational development and during childhood were both associated with having AF later in life. Furthermore, this association was even stronger in the absence of established risk factors for AF. These findings indicate that SHS may be an important, potentially modifiable risk factor for the development of AF, operating outside of known mechanisms for the arrhythmia. Finally, this research suggests that parental

References (33)

  • J. Andrade et al.

    The clinical profile and pathophysiology of atrial fibrillation: relationships among clinical features, epidemiology, and mechanisms

    Circ Res

    (2014)
  • T.A. Dewland et al.

    Incident atrial fibrillation among Asians, Hispanics, blacks, and whites

    Circulation

    (2013)
  • Committee on Secondhand Smoke Exposure and Acute Coronary Events IoM. Secondhand Smoke Exposure and Cardiovascular Effects: Making Sense of the Evidence

    (2009)
  • J.J. Prochaska et al.

    Cardiology Rx for Change: improving clinical attention to tobacco use and secondhand smoke exposure in cardiology

    Clin Cardiol

    (2011)
  • J.M. Lightwood et al.

    Declines in acute myocardial infarction after smoke-free laws and individual risk attributable to secondhand smoke

    Circulation

    (2009)
  • C.E. Tan et al.

    Association between smoke-free legislation and hospitalizations for cardiac, cerebrovascular, and respiratory diseases: a meta-analysis

    Circulation

    (2012)
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    Dr Marcus has received research support from the NIH, PCORI, SentreHeart, Medtronic, and Pfizer and is a consultant for and holds equity in InCarda. This research was made possible in part by the Clinical and Translational Research Fellowship Program, a program of the University of California, San Francisco’s (UCSF) Clinical and Translational Science Institute (CTSI) that is sponsored in part by the National Center for Advancing Translational Sciences, National Institutes of Health (NIH), through UCSF-CTSI Grant Number TL1 TR000144 and the Doris Duke Charitable Foundation (DDCF). The contents are solely the responsibility of the authors and do not necessarily represent the official views of the NIH, UCSF, or the DDCF.

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