title: Validation of PR interval length as a criterion for development of atrial fibrillation in non-Hispanic whites, African Americans and Hispanics.
abstract: BACKGROUND
  PR interval prolongation on electrocardiogram (ECG) increases the risk of atrial fibrillation (AF). Non-Hispanic Whites are at higher risk of AF compared to African Americans and Hispanics. However, it remains unknown if prolongation of the PR interval for the development of AF varies by race/ethnicity. Therefore, we determined whether race affects the PR interval length's ability to predict AF and if the commonly used criterion of 200 ms in AF prediction models can continue to be used for non-White cohorts.
  
  
  METHODS
  This is a retrospective epidemiological study of consecutive inpatient and outpatients. An ECG database was initially interrogated. Patients were included if their initial ECG demonstrated sinus rhythm and had two or more electrocardiograms and declared a race and/or ethnicity as non-Hispanic White, African American or Hispanic. Development of AF was stratified by race/ethnicity along varying PR intervals. Cox models controlled for age, gender, race/ethnicity, systolic blood pressure, BMI, QRS, QTc, heart rate, murmur, treatment for hypertension, heart failure and use of AV nodal blocking agents to assess PR interval's predictive ability for development of AF.
  
  
  RESULTS
  50,870 patients met inclusion criteria of which 5,199 developed AF over 3.72 mean years of follow-up. When the PR interval was separated by quantile, prolongation of the PR interval to predict AF first became significant in Hispanic and African Americans at the 92.5th quantile of 196-201 ms (HR: 1.42, 95% CI: 1.09-1.86, p=0.01; HR: 1.32, 95% CI: 1.07-1.64, p=0.01, respectively) then in non-Hispanic Whites at the 95th quantile at 203-212 ms (HR: 1.24, 95% CI: 1.24-1.53, p=0.04). For those with a PR interval above 200 ms, African Americans had a lower risk than non-Hispanic Whites to develop AF (HR: 0.80, 95% CI: 0.64-0.95, p=0.012), however, no significant difference was demonstrated in Hispanics.
  
  
  CONCLUSIONS
  This is the first study to validate a PR interval value of 200 ms as a criterion in African Americans and Hispanics for the development of AF. However, a value of 200 ms may be less sensitive as a predictive measure for the development of AF in African Americans compared to non-Hispanic Whites.
authors.affiliation: Division of Cardiology, Department of Medicine, Montefiore Medical Center, Bronx, NY.
authors.forename: Eric
authors.initials: E
authors.lastname: Shulman
authors.affiliation: Division of Cardiology, Department of Medicine, Montefiore Medical Center, Bronx, NY.
authors.forename: Philip
authors.initials: P
authors.lastname: Aagaard
authors.affiliation: Division of Cardiology, Department of Medicine, Montefiore Medical Center, Bronx, NY.
authors.forename: Faraj
authors.initials: F
authors.lastname: Kargoli
authors.affiliation: Division of Cardiology, Department of Medicine, Montefiore Medical Center, Bronx, NY.
authors.forename: Ethan
authors.initials: E
authors.lastname: Hoch
authors.affiliation: Department of Environmental Health Sciences, Johns Hopkins University, Baltimore, MD.
authors.forename: Laura
authors.initials: L
authors.lastname: Zheng
authors.affiliation: Division of Cardiology, Department of Medicine, Montefiore Medical Center, Bronx, NY.
authors.forename: Luigi
authors.initials: L
authors.lastname: Di Biase
authors.affiliation: Division of Cardiology, Department of Medicine, Montefiore Medical Center, Bronx, NY.
authors.forename: John
authors.initials: J
authors.lastname: Fisher
authors.affiliation: Division of Cardiology, Department of Medicine, Montefiore Medical Center, Bronx, NY.
authors.forename: Jay
authors.initials: J
authors.lastname: Gross
authors.affiliation: Division of Cardiology, Department of Medicine, Montefiore Medical Center, Bronx, NY.
authors.forename: Soo
authors.initials: S
authors.lastname: Kim
authors.affiliation: Division of Cardiology, Department of Medicine, Montefiore Medical Center, Bronx, NY.
authors.forename: Kevin
authors.initials: K
authors.lastname: Ferrick
authors.affiliation: Division of Cardiology, Department of Medicine, Montefiore Medical Center, Bronx, NY. Electronic address: akrumerm@montefiore.org.
authors.forename: Andrew
authors.initials: A
authors.lastname: Krumerman
mesh_terms: D001741:Black or African American / Q000706:statistics & numerical data*; D000368:Aged; D001281:Atrial Fibrillation / Q000208:ethnology* / Q000401:mortality*; D003936:Diagnosis, Computer-Assisted / Q000379:methods; D004562:Electrocardiography / Q000379:methods / Q000706:statistics & numerical data*; D005260:Female; D006339:Heart Rate; D006630:Hispanic or Latino / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009518:New York / Q000208:ethnology; D015995:Prevalence; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods; D012680:Sensitivity and Specificity; D015996:Survival Rate; D044465:White People / Q000706:statistics & numerical data*
keywords: African American; Atrial fibrillation; Effect modification; Hispanic; PR interval; Racial disparities; White