Abstract 17920: The Prognostic Value of Positive T waves in Lead aVR: A Simple Risk Marker of Sudden and Non-Sudden Cardiac Death in Patients With Ischemic Cardiomyopathy and Poor Left Ventricular Ejection Fraction
Background: The electrocardiogram (ECG) is valuable in identifying cardiac patients at high risk for sudden cardiac (SCD) and cardiovascular (CVD) death. However, due to complicated ECG patterns found in high risk cardiac patients, many high risk ECG markers fail to predict risk. A simple and reliable risk marker in such populations is needed. There is growing evidence that repolarization abnormalities in the left ventricle are strongly correlated with the direction of T waves in lead aVR and constitute a marker of CVD. We sought to evaluate the prognostic value of positive T waves in lead aVR (+T/aVR) in patients with ischemic cardiomyopathy eligible for the primary prevention of SCD with an implantable cardioverter-defibrillator (ICD).
Methods: Subjects were recruited from PAREPET study (Prediction of ARrhythmic Events using Positron Emission Tomography). Resting 12-lead ECGs were extracted from baseline 24-hour high-resolution holter recordings obtained at start of the study. Patients with persistent pacing or left bundle branch block were excluded. The presence of +T/aVR (>0 mm) was prospectively evaluated by a blinded reviewer and endpoints were evaluated by phone at 3-month intervals. Endpoints were determined by a blinded committee of cardiologists. ICD discharges due to ventricular fibrillation or tachycardia (>240 beats/min) were considered equivalent to SCD.
Results: The sample was mainly composed of older male adults (n=155, age 65+12, 90% male, EF 29+9%). After a mean follow up of 4 years, 15% of those with +T/aVR (n=84, 54%) died from SCD and 32% died from CVD, compared to only 3% and 10% of those without +T/aVR (n=71, 46%), respectively. In multivariate cox regression, the presence of +T/aVR was a significant predictor of SCD (Hazard Ratio 5.3 [95% CI 1.2-23.6]) and CVD (Hazard Ratio 3.0 [95% CI 1.3-7.0]) independently from age, sex, and EF.
Conclusions: The presence of +T/aVR can be easily visualized on the 12-lead ECG without the need for advanced computerized algorithms. It can be a simple and reliable tool to identify cardiac patients at greater risk for SCD and potential ICD benefit or at greater risk for CVD for more aggressive therapy (i.e. cardiac resynchronization therapy).
- © 2013 by American Heart Association, Inc.