title: Electrocardiographic Predictors of Incident Atrial Fibrillation.
abstract: Atrial fibrillation (AF) is likely secondary to multiple different pathophysiological mechanisms that are increasingly but incompletely understood. Motivated by the hypothesis that 3 previously described electrocardiographic predictors of AF identify distinct AF mechanisms, we sought to determine if these electrocardiographic findings independently predict incident disease. Among Cardiovascular Health Study participants without prevalent AF, we determined whether left anterior fascicular block (LAFB), a prolonged QTC, and atrial premature complexes (APCs) each predicted AF after adjusting for each other. We then calculated the attributable risk in the exposed for each electrocardiographic marker. LAFB and QTC intervals were assessed on baseline 12-lead electrocardiogram (n = 4,696). APC count was determined using 24-hour Holter recordings obtained in a random subsample (n = 1,234). After adjusting for potential confounders and each electrocardiographic marker, LAFB (hazard ratio [HR] 2.1, 95% confidence interval [CI] 1.1 to 3.9, p = 0.023), a prolonged QTC (HR 2.5, 95% CI 1.4 to 4.3, p = 0.002), and every doubling of APC count (HR 1.2, 95% CI 1.1 to 1.3, p <0.001) each remained independently predictive of incident AF. The attributable risk of AF in the exposed was 35% (95% CI 13% to 52%) for LAFB, 25% (95% CI 0.6% to 44%) for a prolonged QTC, and 34% (95% CI 26% to 42%) for APCs. In conclusion, in a community-based cohort, 3 previously established electrocardiogram-derived AF predictors were each independently associated with incident AF, suggesting that they may represent distinct mechanisms underlying the disease.
authors.affiliation: Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, University of California, San Francisco, San Francisco, California.
authors.forename: Kaylin T
authors.initials: KT
authors.lastname: Nguyen
authors.affiliation: Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, California.
authors.forename: Eric
authors.initials: E
authors.lastname: Vittinghoff
authors.affiliation: Knight Cardiovascular Institute, Oregon Health and Science University, Portland, Oregon.
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Dewland
authors.affiliation: Department of Medicine, Stanford University School of Medicine, Stanford, California.
authors.forename: Mala C
authors.initials: MC
authors.lastname: Mandyam
authors.affiliation: Division of Cardiology, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: Phyllis K
authors.initials: PK
authors.lastname: Stein
authors.affiliation: Division of Public Health Sciences, Department of Epidemiology and Prevention, Epidemiological Cardiology Research Center, Wake Forest School of Medicine, Winston-Salem, North Carolina.
authors.forename: Elsayed Z
authors.initials: EZ
authors.lastname: Soliman
authors.affiliation: Cardiovascular Health Research Unit, Department of Epidemiology, University of Washington, Seattle, Washington.
authors.forename: Susan R
authors.initials: SR
authors.lastname: Heckbert
authors.affiliation: Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, University of California, San Francisco, San Francisco, California. Electronic address: marcusg@medicine.ucsf.edu.
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Marcus
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000503:physiopathology; D018880:Atrial Premature Complexes / Q000175:diagnosis; D015992:Body Mass Index; D015331:Cohort Studies; D004562:Electrocardiography / Q000379:methods; D005260:Female; D006801:Humans; D015994:Incidence; D011237:Predictive Value of Tests; D015995:Prevalence; D018570:Risk Assessment; D012307:Risk Factors; D012680:Sensitivity and Specificity