Author + information
- Received April 22, 1999
- Revision received September 23, 1999
- Accepted November 10, 1999
- Published online March 1, 2000.
- Takanori Ikeda, MDa,* (, )
- Takao Sakata, MDa,
- Mitsuaki Takami, MDa,
- Naoki Kondo, MDa,
- Naoki Tezuka, MDa,
- Takeshi Nakae, MDa,
- Mahito Noro, MDa,
- Yoshihisa Enjoji, MDa,
- Ryoji Abe, MDa,
- Kaoru Sugi, MDa and
- Tetsu Yamaguchi, MDa
- ↵*Reprint requests and correspondence: Dr. Takanori Ikeda, Staff Cardiologist, Third Department of Internal Medicine, Ohashi Hospital, Toho University School of Medicine, 2-17-6 Ohashi, Meguro, Tokyo 153-8515, Japan
Portions of the results were presented at the 48th annual scientific sessions of the American College of Cardiology, New Orleans, Louisiana, March 7–10, 1999, and at the 20th annual scientific sessions of NASPE, Toronto, Ontario, Canada, May 12–15, 1999.
The aim of the present study was to determine whether the combination of two markers that reflect depolarization and repolarization abnormalities can predict future arrhythmic events after acute myocardial infarction (MI).
Although various noninvasive markers have been used to predict arrhythmic events after MI, the positive predictive value of the markers remains low.
We prospectively assessed T-wave alternans (TWA) and late potentials (LP) by signal-averaged electrocardiogram (ECG) and ejection fraction (EF) in 102 patients with successful determination results after acute MI. The TWA was analyzed using the power-spectral method during supine bicycle exercise testing. No antiarrhythmic drugs were used during the follow-up period. The study end point was the documentation of ventricular arrhythmias.
The TWA was present in 50 patients (49%), LP present in 21 patients (21%), and an EF <40% in 28 patients (27%). During a follow-up period of 13 ± 6 months, symptomatic, sustained ventricular tachycardia or ventricular fibrillation occurred in 15 patients (15%). The event rates were significantly higher in patients with TWA, LP, or an abnormal EF. The sensitivity and the negative predictive value of TWA in predicting arrhythmic events were very high (93% and 98%, respectively), whereas its positive predictive value (28%) was lower than those for LP and EF. The highest positive predictive value (50%) was obtained when TWA and LP were combined.
The combined assessment of TWA and LP was associated with a high positive predictive value for an arrhythmic event after acute MI. Therefore, it could be a useful index to identify patients at high risk of arrhythmic events.
☆ This study was supported in part by a grant from the Special Coordinating Funds for Clinical Research from Eisai Co., Ltd. (Dr. Ikeda); by a grant from Dr. Takeshi Yanase of Toho University School of Medicine (Dr. Ikeda); and by a grant from the Shibata foundation (Dr. Ikeda).
- Received April 22, 1999.
- Revision received September 23, 1999.
- Accepted November 10, 1999.
- American College of Cardiology