ST-T Wave Abnormality in Lead aVR and Reclassification of Cardiovascular Risk (from the National Health and Nutrition Examination Survey-III)

• Published in: The American journal of cardiology Vol. 112; no. 6; pp. 805 - 810
• Main Authors: Badheka, Apurva O., Patel, Nileshkumar J., Grover, Peeyush M., Shah, Neeraj, Singh, Vikas, Deshmukh, Abhishek, Mehta, Kathan, Chothani, Ankit, Hoosien, Michael, Rathod, Ankit, Savani, Ghanshyambhai T., Marzouka, George R., Gupta, Sandeep, Mitrani, Raul D., Moscucci, Mauro, Cohen, Mauricio G.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 15.09.2013; Elsevier Limited
• Subjects: Age; Body mass index; Cardiovascular; Cardiovascular disease; Cardiovascular Diseases - diagnosis; Cardiovascular Diseases - epidemiology; Cardiovascular Diseases - physiopathology; Coronary vessels; Electrocardiography; Female; Follow-Up Studies; Forecasting; Gender; Humans; Hypertension; Incidence; Male; Middle Aged; Mortality; Multivariate analysis; Nutrition; Nutrition Surveys - methods; Population; Potassium; Prevalence; Retrospective Studies; Risk Assessment - methods; Risk Factors; Studies; Survival Rate - trends; United States - epidemiology; Variables; Ventricular Remodeling; United States; USA
• ISSN: 0002-9149; 1879-1913; 1879-1913
• DOI: 10.1016/j.amjcard.2013.04.058

Electrocardiographic lead aVR is often ignored in clinical practice. The aim of this study was to investigate whether ST-T wave amplitude in lead aVR predicts cardiovascular (CV) mortality and if this variable adds value to a traditional risk prediction model. A total of 7,928 participants enrolled in the National Health and Nutrition Examination Survey (NHANES) III with electrocardiographic data available were included. Each participant had 13.5 ± 3.8 years of follow-up. The study sample was stratified according to ST-segment amplitude and T-wave amplitude in lead aVR. ST-segment elevation (>8 μV) in lead aVR was predictive of CV mortality in the multivariate analysis when not accounting for T-wave amplitude. The finding lost significance after including T-wave amplitude in the model. A positive T wave in lead aVR (>0 mV) was the strongest multivariate predictor of CV mortality (hazard ratio 3.37, p <0.01). The addition of T-wave amplitude in lead aVR to the Framingham risk score led to a net reclassification improvement of 2.7% of subjects with CV events and 2.3% of subjects with no events (p <0.01). Furthermore, in the intermediate-risk category, 20.0% of the subjects in the CV event group and 9.1% of subjects in the no-event group were appropriately reclassified. The absolute integrated discrimination improvement was 0.012 (p <0.01), and the relative integrated discrimination improvement was 11%. In conclusion, T-wave amplitude in lead aVR independently predicts CV mortality in a cross-sectional United States population. Adding T-wave abnormalities in lead aVR to the Framingham risk score improves model discrimination and calibration with better reclassification of intermediate-risk subjects.