AHA 2005 Studies Demonstrate Effectiveness of Microvolt T-Wave Alternans in Predicting Sudden Cardiac Death Regardless of Ejection Fraction on 2358 patients

T Wave Alternans Multiple presentations were given at The American Hospital Association Meeting in Dallas, Texas: Three prominent presentations, collectively representing 2,358 study patients further validates Microvolt T-Wave Alternans as an independent predictor of sudden cardiac death and sustained ventricular events regardless of the patients Ejection Fraction or EF (a measure of the heart's pumping ability).

Dr. Paul Chan, presenting information from the Lindner Clinical Trials Center in Cincinnati, reported on 768 consecutively enrolled ischemic SCD-HeFT type patients with an EF of less than or equal to 35%. In evaluating the predictive ability of Microvolt T-Wave Alternans the authors concluded that this non-invasive diagnostic test is a strong and independent predictor of mortality and appropriate ICD therapy among Madit II and SCD-HeFT eligible patients with ischemic cardiomyopathy.

Also reporting on a patient population with ejection fraction levels of 40% or less, Dr Elizabeth Kaufman from Case Western Reserve University in Cleveland, Ohio shared results from a study of 549 heart failure patients. The hypothesis being evaluated was the predictive ability of "indeterminate" MTWA tests. In this study the authors concluded that in patients with left ventricular dysfunction an indeterminate MTWA test predicted death or sustained ventricular arrhythmias at least as well as a positive test and that conversely, a negative MTWA test is associated with a very low risk of death or sustained ventricular arrhythmia.

In the third presentation Dr. Takanori Ikeda from Kyorin University in Tokyo, Japan evaluated seemingly low risk patients with an ejection fraction equal to or greater than 40% who had also experienced an acute myocardial infarction or heart attack. In this prospectively enrolled study of 1,012 patients each patient was evaluated with 10 different prognostic indicators including Signal Averaged ECG (SAECG) and non sustained ventricular tachycardia on Holter Monitoring in addition to MTWA. After performing a multivariate regression analysis MTWA was found to be the most powerful predictor. The conclusion being that in heart attack victims with preserved left ventricular ejection fraction, MTWA was not only a strong predictor of sudden cardiac death but that MTWA may be useful in identifying patients in this population who need implantable defibrillators.