Risk Stratification for Sudden Cardiac Death in Dilated Cardiomyopathy Using Microvolt-Level T-Wave Alternans

Abstract

Predicting sudden cardiac death (SCD) in patients with dilated cardiomyopathy (DCM) is difficult, so the present study evaluated the efficacy of microvolt-level T-wave alternans (TWA) and compared it with conventional parameters for prospective risk stratification of SCD in patients with DCM. Eighty-two patients with DCM (53±15 years old, 67 M/15 F) underwent assessment of TWA, left ventricular end-diastolic diameter (LVDd), left ventricular ejection fraction (LVEF), signal-averaged ECG, and analysis of 24-h Holter monitoring and QT dispersion (QTd). The endpoint of the study was defined as either SCD or documented sustained ventricular tachycardia/ventricular fibrillation (SVT/VF) during the follow-up period. During an average follow-up period of 24 months, 1 patient died suddenly and 9 patients had SVT/VF. Kaplan-Meier survival analysis showed that TWA, LVEF (≤35%), nonsustained ventricular tachycardia, and QTd (>90 ms) were significant univariate risk stratifiers (p<0.005, p<0.005, p<0.005, and p<0.05, respectively). Multivariate Cox regression analysis showed that TWA and the LVEF were statistically significant independent risk stratifiers (p<0.05 and p<0.01, respectively). A combination of TWA and LVEF identified high risk DCM patients (p<0.01); TWA for the electrical substrate and the LVEF for the hemodynamic function. (Jpn Circ J 2001; 65: 76 -80)

Microvolt T-Wave Alternans as a Predictor of Ventricular Tachyarrhythmias

“…Sensitivity was found to be 78% to 93% and specificity was 45% to 61% for predicting VT/VF/SCD according to these criteria. 2,3,10,14,15 The characteristics of TWA testing by exercise were found to be those of high sensitivity and moderate specificity to predict VT. The heart rate at which V alt exceeds positivity criteria is called onset heart rate.…”

Microvolt T-Wave Alternans for the Risk Stratification of Ventricular Tachyarrhythmic Events

“…3). Three studies performed a multivariate Cox regression analysis to determine the independent predictive value of several commonly used tests for risk stratification of arrhythmic events including MTWA (Table 5) (28,36,37). In these three studies, MTWA was independently predictive of arrhythmic events in adjusted analysis.…”

Combined prognostic value of peak O2 uptake and microvolt level T-wave alternans in patients with idiopathic dilated cardiomyopathy

“…Given these results, MTWA demonstrated to be a significant predictor of arrhythmic events ( p = 0.0036). Adachi et al [17] showed that MTWA was a statistically significant independent risk stratifier ( p b 0.01) of SCD in 82 consecutive patients with DCM. Kitamura et al [20] investigated 104 patients with DCM during a mean follow-up of 21 months: of the 12 major arrhythmic events, 11 occurred in patients with abnormal MTWA ( p = 0.0001).…”

“…The results of several studies [15][16][17][18][19][20][21][22]30,31] demonstrated that MTWA is a promising predictor of SCD or major arrhythmic events in patients with DCM.…”

“…Several clinical and experimental studies [12][13][14] have shown that MTWA is strictly correlated with presence of inducible and spontaneous ventricular tachycardia/fibrillation (VT/VF). Therefore, MTWA has been proposed as a new non-invasive tool for stratification of patients with DCM at high risk of SCD and malignant arrhythmias [15][16][17][18][19][20][21][22].…”