T wave alternans is a predictor of death in patients with congestive heart failure

Few data are available about the prognostic role of T wave alternans in patients with congestive heart failure. To assess the ability of T wave alternans, used alone or in combination with other risk markers, to predict cardiac death in decompensated patients, we enrolled 46 patients, mean age 59±9, males 89%, ischemic etiology 61%, NYHA class III 35%, left ventricular ejection fraction 29±7%. After 1.6 years follow-up, seven patients died from cardiac death (16%), non-sudden in six (86%) and sudden in one (14%). T wave alternans was positive in 24 (52%), negative in 13 (28%), indeterminate in nine patients (20%). T wave alternans was positive in all patients with events (100%) but only in 16 of 37 patients without (41%) (P=0.02). Other predictors of cardiac death were O₂ consumption at the peak of exercise (P=0.03), standard deviation of all NN intervals (P=0.05) and Wedge pressure (P=0.03). When receiver operator characteristics curves were calculated, the highest area (0.73) was found for O₂ consumption at the peak of exercise considering the single variables and for O₂ consumption at the peak of exercise plus T wave alternans (0.79) for combination of them; the comparison of the two receiver operator characteristics curves did not reach statistical difference (P=0.5). In conclusion, this is the first study reporting that T wave alternans can predict cardiac death, with a marginal additional prognostic power when used in combination with measurement of O₂ consumption at the peak of exercise.