TY - JOUR
T1 - Microvolt T-wave alternans distinguishes between patients likely and patients not likely to benefit from implanted cardiac defibrillator therapy
T2 - A solution to the Multicenter Automatic Defibrillator Implantation Trial (MADIT) II conundrum
AU - Bloomfield, Daniel M.
AU - Steinman, Richard C.
AU - Namerow, Pearila B.
AU - Parides, Michael
AU - Davidenko, Jorge
AU - Kaufman, Elizabeth S.
AU - Shinn, Timothy
AU - Curtis, Anne
AU - Fontaine, John
AU - Holmes, Douglas
AU - Russo, Andrea
AU - Tang, Chuen
AU - Bigger, J. Thomas
PY - 2004/10/5
Y1 - 2004/10/5
N2 - Background - In 2003, the Centers for Medicaid and Medicare Services recommended QRS duration as a means to identify MADIT II-like patients suitable for implanted cardiac defibrillator (ICD) therapy. We compared the ability of microvolt T-wave alternans and QRS duration to identify groups at high and low risk of dying among heart failure patients who met MADIT II criteria for ICD prophylaxis. Methods and Results - Patients with MADIT II characteristics and sinus rhythm had a microvolt T-wave alternans exercise test and a 12-lead ECG. Our primary end point was 2-year all-cause mortality. Of 177 MADIT II-like patients, 32% had a QRS duration >120 ms, and 68% had an abnormal (positive or indeterminate) microvolt T-wave alternans test. During an average follow-up of 20±6 months, 20 patients died. We compared patients with an abnormal microvolt T-wave alternans test to those with a normal (negative) test, and patients with a QRS >120 ms with those with a QRS ≤120 ms; the hazard ratios for 2-year mortality were 4.8 (P=0.020) and 1.5 (P=0.367), respectively. The actuarial mortality rate was substantially lower among patients with a normal microvolt T-wave alternans test (3.8%; 95% confidence interval: 0, 9.0) than the mortality rate in patients with a narrow QRS (12.0%; 95% confidence interval: 5.6, 18.5). The corresponding false-negative rates are 3.5% and 10.2%, respectively. Conclusion - Among MADIT II-like patients, a microvolt T-wave alternans test is better than QRS duration at identifying a high-risk group and also better at identifying a low-risk group unlikely to benefit from ICD therapy.
AB - Background - In 2003, the Centers for Medicaid and Medicare Services recommended QRS duration as a means to identify MADIT II-like patients suitable for implanted cardiac defibrillator (ICD) therapy. We compared the ability of microvolt T-wave alternans and QRS duration to identify groups at high and low risk of dying among heart failure patients who met MADIT II criteria for ICD prophylaxis. Methods and Results - Patients with MADIT II characteristics and sinus rhythm had a microvolt T-wave alternans exercise test and a 12-lead ECG. Our primary end point was 2-year all-cause mortality. Of 177 MADIT II-like patients, 32% had a QRS duration >120 ms, and 68% had an abnormal (positive or indeterminate) microvolt T-wave alternans test. During an average follow-up of 20±6 months, 20 patients died. We compared patients with an abnormal microvolt T-wave alternans test to those with a normal (negative) test, and patients with a QRS >120 ms with those with a QRS ≤120 ms; the hazard ratios for 2-year mortality were 4.8 (P=0.020) and 1.5 (P=0.367), respectively. The actuarial mortality rate was substantially lower among patients with a normal microvolt T-wave alternans test (3.8%; 95% confidence interval: 0, 9.0) than the mortality rate in patients with a narrow QRS (12.0%; 95% confidence interval: 5.6, 18.5). The corresponding false-negative rates are 3.5% and 10.2%, respectively. Conclusion - Among MADIT II-like patients, a microvolt T-wave alternans test is better than QRS duration at identifying a high-risk group and also better at identifying a low-risk group unlikely to benefit from ICD therapy.
KW - Coronary disease
KW - Death, sudden
KW - Defibrillation
KW - Heart arrest
KW - Heart failure
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U2 - 10.1161/01.CIR.0000143160.14610.53
DO - 10.1161/01.CIR.0000143160.14610.53
M3 - Article
C2 - 15451804
AN - SCOPUS:20844456962
SN - 0009-7322
VL - 110
SP - 1885
EP - 1889
JO - Circulation
JF - Circulation
IS - 14
ER -