Dr. Stein received travel support from GE Medical to present results at ACC 2008.
Ambulatory ECG-Based T-Wave Alternans Predicts Sudden Cardiac Death in High-Risk Post-MI Patients with Left Ventricular Dysfunction in the EPHESUS Study
Version of Record online: 28 JUN 2008
© 2008 Wiley Periodicals, Inc.
Journal of Cardiovascular Electrophysiology
Volume 19, Issue 10, pages 1037–1042, October 2008
How to Cite
STEIN, P. K., SANGHAVI, D., DOMITROVICH, P. P., MACKEY, R. A. and DEEDWANIA, P. (2008), Ambulatory ECG-Based T-Wave Alternans Predicts Sudden Cardiac Death in High-Risk Post-MI Patients with Left Ventricular Dysfunction in the EPHESUS Study. Journal of Cardiovascular Electrophysiology, 19: 1037–1042. doi: 10.1111/j.1540-8167.2008.01225.x
This study was funded in part by Pfizer Pharmaceuticals and GE Healthcare.
The MMA algorithm used in this analysis is proprietary software owned and operated by GE Healthcare, who supported this data analysis. However, no one from GE Healthcare was in any way involved with the actual analysis or interpretation of the results.
Manuscript received 1 February 2008; Revised manuscript received 25 February 2008; Accepted for publication 5 March 2008.
- Issue online: 20 SEP 2008
- Version of Record online: 28 JUN 2008
- sudden death;
- T-wave alternans;
- ambulatory ECG;
- modified moving average
Background: Exercise microvolt T-wave alternans (TWA) identifies sudden cardiac death (SCD) risk. TWA can be measured from ambulatory ECGs (AECGs) using modified moving average (MMA) method. Whether MMA TWA from AECGs predicts SCD in post-MI patients with left ventricular dysfunction (LVD) is unknown.
Methods: EPHESUS enrolled hospitalized post-MI patients with heart failure and/or diabetes with LVD. Before randomization to drug treatment, AECGs were obtained in 493 patients. Of them, 46 died of cardiovascular causes, including 18 of SCD. Patients alive at end of follow-up (N = 92) were matched with 46 nonsurvivors based on age, gender, and diabetes. MMA TWA was analyzed using MARSPC system (GE Healthcare, Milwaukee, WI, USA). The three highest TWA values from artifact-free periods were averaged for AECG channels corresponding to leads V1 and V3. SCD prediction was tested with a prespecified 47 μV cutpoint and at a cutpoint maximizing the separation between SCD patients versus survivors or non-SCD.
Results: TWA in either lead was higher for patients with SCD (P ≤ 0.05) versus survivors or non-SCD. TWA ≥ 47 μV was associated with RR = 5.2 (95%CI = 1.8–13.6, P = 0.002) in V1 and RR = 5.5 (95% CI = 2.2–13.8, P < 0.001) in V3 for SCD. The optimal cutpoint for TWA in V1 was ≥43 μV (RR = 5.9 [95%CI = 2.2–15.8, P < 0.001]). The optimal cutpoint in V3 was ≥47 μV. TWA greater than the optimal cutpoint in either lead was associated with RR = 7.1 (95%CI = 2.7–18.3, P < 0.001) for SCD, with 11 out of 18 patients dying of SCD.
Conclusions: AECG-based TWA measured with MMA is a powerful predictor of SCD in high-risk post-MI patients with LV dysfunction.