Abstract 17513: J Point Elevation and Cardiovascular Mortality: Insights From National Health And Nutrition Examination Survey-III
Background: The significance of early repolarization has recently been questioned with associated increased risk of cardiovascular mortality (CM). We assessed the prognostic significance of J point elevation (JPE) and its role in predicting CM in general population free of coronary artery disease or risk equivalents (CAD).
Methods: Study population consisted of all adults >40 yo with EKG data available, enrolled into NHANES III (1988 to 1994). This self-weighting sample was representative of US population of 48138059 individuals with a follow-up period of 64497.75 person-years. Individuals with missing mortality data, history of coronary artery disease or equivalant, diabetes, peripheral artery disease, heart failure, stroke were excluded for this study. Patients with major ECG abnormalities, myocardial injury or infarction score>20, non-sinus rhythm, heart rate>120, QRS interval >120 and probable LVH were also excluded. All ECGs were computer- coded by the Minnesota coding. CM was linked to the National Death Index and was based on ICD-10. We divided the subjects into quartiles based on the sum of J point elevation in all leads.
Results: Our dataset consisted of 4780 subjects with mean age of 57.28 ± 13.00 years (44.5% men and 88% whites). On multivariate analysis none of the quartiles were found to be significantly associated with CM after controlling for cardiovascular risk factors and serum electrolyte abnormalities (See Table). Subdivision of ECGs based on lead groups did not change this association Serum Calcium (p=0.05) and potassium (p<0.01) were significant predictors of J point elevation.
Conclusion: We found no significant association between JPE and CM over long term follow-up in this cross-sectional United States population free from known heart disease. JPE may serve as a phenotype marker for underlying serum electrolyte abnormalities and not be the primary cause of CM.
- © 2012 by American Heart Association, Inc.