Europace Advance Access originally published online on October 8, 2009
Europace 2009 11(11):1522-1528; doi:10.1093/europace/eup294
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Electrocardiography and Risk Stratification
Risk stratification by T-wave morphology for cardiovascular mortality in patients with systolic heart failure
1 Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, No. 7 Chung-Shan South Road, Taipei 100, Taiwan; 2 Division of Cardiology, Departments of Surgery, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan; 3 Graduate Institute of Clinical Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, No. 7 Chung-Shan South Road, Taipei 100, Taiwan
Aims: The objective was to investigate the prognostic value of T-wave morphology in systolic heart failure patients. T-wave morphology descriptors on standard 12-lead electrocardiograms (ECG) have been shown to have prognostic importance concerning the arrhythmic susceptibility of patients with previous myocardial infarction. However, these descriptors have not been considered with regard to further risk stratification in patients with systolic heart failure.
Methods and results: Patients with systolic heart failure [defined by a left ventricular ejection fraction (LVEF) <50%] were enrolled. Standard digitized 12-lead ECGs were used for analysis of T-wave morphology descriptors [lead dispersion, T-wave morphology dispersion, percentage of the loop area, percentage of the outer area, and the total cosine between QRS and T-wave (TCRT)]. A total of 650 patients with a mean age of 63 ± 14 years were enrolled and followed-up for 2.7 ± 1.8 years. The mean LVEF was 36 ± 9%. During this study, the total mortality rate was 32.7% and cardiovascular mortality rate was 22.3%. A stepwise backward Cox regression analysis showed that cardiovascular mortality was significantly associated with age (P < 0.001), diabetes mellitus (P = 0.022), haemoglobin (P = 0.001), LVEF (P = 0.001), and TCRT (P = 0.003). On the basis of a median TCRT of –0.473 as a cut-off point, a significant difference in cardiovascular mortality was observed from a Kaplan–Meier survival curve (P = 0.01). Total cosine between QRS and T-wave further stratified the risk of LVEF (P = 0.007), age (P = 0.001), haemoglobin (P < 0.001), and diabetes mellitus (P < 0.001) in cardiovascular mortality for these patients.
Conclusion: Total cosine between QRS and T-wave may provide further risk stratification for and therefore impact on the prognosis of patients with systolic heart failure.
Key Words: T-wave morphology, Total cosine between QRS and T-wave, Systolic heart failure, Cardiovascular disease mortality
* Corresponding author. Tel: +886 2 2312 3456, ext 65438, Fax: +886 2 23515811, Email: ylho{at}ntu.edu.tw
These authors contributed equally to the work.
Manuscript submitted 8 May 2009. Accepted after revision 6 September 2009.