In patients with hypertrophic cardiomyopathy, the presence of microvolt T-wave alternans increased the risk of postexercise nonsustained ventricular tachycardia (OR 21.03).
Observational (n=88)
No
Does microvolt T-wave alternans assessment predict nonsustained ventricular tachycardia episodes in patients with hypertrophic cardiomyopathy?
While TWA is associated with an increased risk of postexercise nVT in HCM patients, it does not add incremental predictive value over other standard electrocardiographic and biomarker parameters.
Effect estimate: OR 21.03 (95% CI 6.28-57.4)
Absolute Event Rate: 67.4% vs 7.1%
p-value: p=<0.001
BACKGROUND: Nonsustained ventricular tachycardia (nVT) may have ominous implications for patients with hypertrophic cardiomyopathy (HCM). The microvolt T-wave alternans (TWA) has been proposed as a noninvasive tool-identifying patients at risk of sudden cardiac death and ventricular tachycardia/fibrillation (VT/VF). The aim of the study was to determine the significance of TWA in predicting nVT episodes and compare how other electrocardiographic parameters can predict the occurrence of nVT. METHODS: The study group consisted of 88 patients with HCM. TWA was assessed during exercise test using the CH2000 system. All patients underwent Holter monitoring (HM) within 2-4 weeks before TWA test (preexercise HM1) and immediately after (postexercise HM2). During HM, we analyzed: arrhythmias, QT intervals, the presence of late ventricular potentials (LP), heart rate variability, heart rate turbulence. RESULTS: Depending on TWA results, the patients were divided into two groups: TWA+; 46 patients (52.3%) with positive/indeterminate results, and TWA-; 42 patients (47.7%) with negative results. The nVT episodes were more frequent among TWA(+) both in HM1 and HM2. The presence of TWA increases the risk of postexercise nVT over twenty times (OR = 21.03). Moreover, in HM1, QTc and LP, and in HM2, again QTc and N-terminal precursor of brain natriuretic peptide proved to be significant predictors of nVT. The addition of TWA to the models did not improve the arrhythmia risk assessment. CONCLUSIONS: Repolarization abnormality plays an important role in generating nVT in patients with HCM, but TWA does not specifically predict the risk of arrhythmic end point.
Trzos et al. (Fri,) conducted a observational in Hypertrophic Cardiomyopathy (n=88). Positive microvolt T-wave alternans (TWA+) vs. Negative microvolt T-wave alternans (TWA-) was evaluated on Postexercise nonsustained ventricular tachycardia (nVT) episodes (OR 21.03, 95% CI 6.28-57.4, p=<0.001). In patients with hypertrophic cardiomyopathy, the presence of microvolt T-wave alternans increased the risk of postexercise nonsustained ventricular tachycardia (OR 21.03).