Impact of Microvolt T-wave Alternans on Malignant Arrhythmia Occurrence and Mortality in Patients with Congestive Heart Failure: Single-Centre Study

ABSTRACTObjectives: The aim of this study was to assess the relation between microvolt T-wave alternans (MTWA) with malignant arrhythmia occurrence and mortality in patients with ventricular systolic function < 40% due to ischemic (CAD) or nonischemic cardiomyopathy (DCMP).Background: The predictive value of T-wave alternans for malignant arrhythmias in patients with congestive heart failure (CHF) is controversial.Methods: In a single-centre, prospective, observational study—including patients with CHF of isch- emic and nonischemic aetiology—we assessed the prognostic value of MTWA for malignant arrhyth- mias and total mortality.Results: This study included 155 patients; aetiology of CHF was CAD in 67.7%, and DCMP in 32.3%. Mean left ventricular ejection fraction (LVEF) was 29%. MTWA results were 38.1% positive, 40.6% negative, and 19.4% indeterminate. Over the median follow-up of 33.8 months, 13 deaths (7 cardiac and 6 noncardiac) were observed. The death rate in MTWA-negative patients did not significantly dif- fer from that in MTWA-non negative patients (p = 0.203). There was also no difference in death rate between CAD and DCMP patients (p = 0.211). In only CAD patients, nonnegative MTWA predicted significantly higher occurrence of malignant arrhythmias (p = 0.033). This correlation was not signifi- cant for the total group (p = 0.100), or for the DCMP subgroup (p = 1.000).Conclusions: The negative predictive value of MTWA for malignant arrhythmias was 79.4%. Signifi- cant reduction of malignant arrhythmias in MTWA-negative patients was valid only in the CAD sub- group. The impact of MTWA on mortality was not significant.