title: Relation of Resting Heart Rate to Incident Atrial Fibrillation (from the Henry Ford Hospital Exercise Testing Project).
abstract: Autonomic nervous system (ANS) dysfunction plays a role in atrial fibrillation (AF) initiation. Cardiorespiratory fitness modulates ANS function and is inversely associated with resting heart rate (RHR) and risk of AF. Thus, we sought to study the association between RHR, as a surrogate for ANS function, and incident AF independent of exercise capacity (EC). We analyzed 51,436 subjects without previous AF who underwent a clinically indicated exercise stress test. Incident AF was ascertained through claims files. RHR was measured before stress testing, and EC was estimated by peak metabolic equivalents of task. We studied the association between RHR categories (<70, 70 to 85 [reference], and >85 beats/min) and incident AF using Cox models adjusted for risk factors and for EC. We tested for interaction between RHR and age, gender, smoking, and EC. Mean (SD) age was 53 (13) years, 53% were men, and 28% were black. Participants with RHR <70 beats/min were older, more likely to be men, have higher EC, and more likely to smoke but less likely to have diabetes and hypertension. Over a median of 5.5 years, RHR <70 beats/min was associated with 14% increased risk of AF (95 CI 6% to 25%) in fully adjusted models, whereas RHR >85 beats/min was not associated with AF risk after adjusting for EC. Results for RHR analyzed continuously and by quartile were similar. No interaction was seen. In conclusion, subjects with low RHR at all levels of EC are at increased risk of AF and may benefit from heart rhythm surveillance, particularly in the presence of other AF risk factors.
authors.affiliation: Department of Medicine, Ciccarone Center for the Prevention of Heart Disease, Johns Hopkins School of Medicine, Baltimore, Maryland.
authors.forename: Amer I
authors.initials: AI
authors.lastname: Aladin
authors.affiliation: Department of Medicine, Ciccarone Center for the Prevention of Heart Disease, Johns Hopkins School of Medicine, Baltimore, Maryland; Department of Medicine, University of Kansas School of Medicine, Wichita, Kansas.
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Al Rifai
authors.affiliation: Department of Medicine, Ciccarone Center for the Prevention of Heart Disease, Johns Hopkins School of Medicine, Baltimore, Maryland.
authors.forename: Shereen H
authors.initials: SH
authors.lastname: Rasool
authors.affiliation: Division of Cardiovascular Medicine, Henry Ford Health System, Detroit, Michigan.
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Keteyian
authors.affiliation: Division of Cardiovascular Medicine, Henry Ford Health System, Detroit, Michigan.
authors.forename: Clinton A
authors.initials: CA
authors.lastname: Brawner
authors.affiliation: Department of Medicine, Ciccarone Center for the Prevention of Heart Disease, Johns Hopkins School of Medicine, Baltimore, Maryland.
authors.forename: Roger S
authors.initials: RS
authors.lastname: Blumenthal
authors.affiliation: Department of Medicine, Ciccarone Center for the Prevention of Heart Disease, Johns Hopkins School of Medicine, Baltimore, Maryland.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Blaha
authors.affiliation: Division of Cardiovascular Medicine, Henry Ford Health System, Detroit, Michigan; Department of Medicine, King Saud bin Abdul-Aziz University for Health Sciences, King Abdullah International Medical Research Center, King Abdul-Aziz Cardiac Center, Ministry of National Guard, Health Affairs, Riyadh, Saudi Arabia.
authors.forename: Mouaz H
authors.initials: MH
authors.lastname: Al-Mallah
authors.affiliation: Department of Medicine, Ciccarone Center for the Prevention of Heart Disease, Johns Hopkins School of Medicine, Baltimore, Maryland. Electronic address: jmcevoy1@jhmi.edu.
authors.forename: John W
authors.initials: JW
authors.lastname: McEvoy
mesh_terms: D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation / Q000453:epidemiology*; D005080:Exercise Test; D017079:Exercise Tolerance; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D015994:Incidence; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D012146:Rest; D012189:Retrospective Studies; D012307:Risk Factors