['Microvolt T-wave alternans (MTWA) testing identifies beat-to-beat fluctuations in T-wave morphology, which have been linked to ventricular arrhythmias. However, clinical studies have produced conflicting results and data in heart failure (HF) have been limited. The aim of this study was to determine the prevalence and incremental prognostic value of spectral MTWA testing in an unselected cohort of patients recently hospitalized with HF.', 'Consecutive admissions with confirmed HF were recruited, and survivors were invited to attend 1 month post-discharge for MTWA testing. A total of 648 of 1003 enrolled patients returned for MTWA testing (58% male, mean age 71 years). Forty-nine per cent were ineligible due to AF, pacemaker dependency, or inability to exercise. Of the 330 MTWA test results, 30% were positive, 24% negative, and 46% indeterminate. Overall, 268 deaths occurred during a median follow-up of 3.1 (interquartile range 1.9-3.9) years. Of the ineligible patients, 48% died vs. 35% of eligible patients (P < 0.001). Of those patients with positive, negative, and indeterminate tests, 27, 35, and 40%, respectively, died (P = 0.12). Even when analysed as non-negative (positive/indeterminate) vs. negative, there was still no between-group difference in mortality (P = 0.95). MTWA results categorized as positive, negative, or indeterminate showed no incremental prognostic value in a multivariable model, which included BNP. Paradoxically, when compared in a binary fashion with a non-negative result, a negative test was an independent predictor of death, as was ineligibility for MTWA testing.'] Does spectral microvolt T-wave alternans testing have no prognostic value in patients recently hospitalized with decompensated heart failure?