TY - JOUR
T1 - Clinical utility of microvolt T-wave alternans testing in identifying patients at high or low risk of sudden cardiac death
AU - Merchant, Faisal M.
AU - Ikeda, Takanori
AU - Pedretti, Roberto F E
AU - Salerno-Uriarte, Jorge A.
AU - Chow, Theodore
AU - Chan, Paul S.
AU - Bartone, Cheryl
AU - Hohnloser, Stefan H.
AU - Cohen, Richard J.
AU - Armoundas, Antonis A.
PY - 2012/8
Y1 - 2012/8
N2 - Background: Previous studies have demonstrated that microvolt T-wave alternans (MTWA) testing is a robust predictor of ventricular tachyarrhythmias and sudden cardiac death (SCD) in at-risk patients. However, recent studies have suggested that MTWA testing is not as good a predictor of " appropriate" implantable cardioverter-defibrillator (ICD) therapy as it is a predictor of SCD in patients without ICDs. Objective: To evaluate the utility of MTWA testing for SCD risk stratification in patients without ICDs. Methods: Patient-level data were obtained from 5 prospective studies of MTWA testing in patients with no history of ventricular arrhythmia or SCD. In these studies, ICDs were implanted in only a minority of patients and patients with ICDs were excluded from the analysis. We conducted a pooled analysis and examined the 2-year risk for SCD based on the MTWA test result. Results: The pooled cohort included 2883 patients. MTWA testing was positive in 856 (30%), negative in 1627 (56%), and indeterminate in 400 (14%) patients. Among patients with a left ventricular ejection fraction (LVEF) of ≤35%, annual SCD event rates were 4.0%, 0.9%, and 4.6% among groups with MTWA positive, negative, and indeterminate test results. The SCD rate was significantly lower among patients with a negative MTWA test result than in patients with either positive or indeterminate MTWA test results (P 35%, annual SCD event rates were 3.0%, 0.3%, and 0.3% among the groups with MTWA positive, negative, and indeterminate test results. The SCD rate associated with a positive MTWA test result was significantly higher than that associated with either negative (P 35%, a positive MTWA test result identifies patients at significantly heightened SCD risk. These findings may have important implications for refining primary prevention ICD treatment algorithms.
AB - Background: Previous studies have demonstrated that microvolt T-wave alternans (MTWA) testing is a robust predictor of ventricular tachyarrhythmias and sudden cardiac death (SCD) in at-risk patients. However, recent studies have suggested that MTWA testing is not as good a predictor of " appropriate" implantable cardioverter-defibrillator (ICD) therapy as it is a predictor of SCD in patients without ICDs. Objective: To evaluate the utility of MTWA testing for SCD risk stratification in patients without ICDs. Methods: Patient-level data were obtained from 5 prospective studies of MTWA testing in patients with no history of ventricular arrhythmia or SCD. In these studies, ICDs were implanted in only a minority of patients and patients with ICDs were excluded from the analysis. We conducted a pooled analysis and examined the 2-year risk for SCD based on the MTWA test result. Results: The pooled cohort included 2883 patients. MTWA testing was positive in 856 (30%), negative in 1627 (56%), and indeterminate in 400 (14%) patients. Among patients with a left ventricular ejection fraction (LVEF) of ≤35%, annual SCD event rates were 4.0%, 0.9%, and 4.6% among groups with MTWA positive, negative, and indeterminate test results. The SCD rate was significantly lower among patients with a negative MTWA test result than in patients with either positive or indeterminate MTWA test results (P 35%, annual SCD event rates were 3.0%, 0.3%, and 0.3% among the groups with MTWA positive, negative, and indeterminate test results. The SCD rate associated with a positive MTWA test result was significantly higher than that associated with either negative (P 35%, a positive MTWA test result identifies patients at significantly heightened SCD risk. These findings may have important implications for refining primary prevention ICD treatment algorithms.
KW - Arrhythmia
KW - heart failure
KW - ICD
KW - Risk stratification
KW - Sudden cardiac death
KW - T-wave alternans
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U2 - 10.1016/j.hrthm.2012.03.014
DO - 10.1016/j.hrthm.2012.03.014
M3 - Article
C2 - 22406384
AN - SCOPUS:84864446744
VL - 9
JO - Heart Rhythm
JF - Heart Rhythm
SN - 1547-5271
IS - 8
ER -