OBJECTIVES: We conducted a collaborative cohort study to evaluate the predictive power of microvolt T-wave alternans (TWA) in patients with preserved left ventricular ejection fraction (LVEF) after myocardial infarction (MI). BACKGROUND: There is little information available about the prognostic value of risk stratification markers in this population. Although these patients have a relatively good prognosis, identifying high-risk patients is important in clinical practice. METHODS: This study enrolled 1,041 post-MI patients with an LVEF > or =40% (average 55 +/- 10%). Microvolt TWA testing was performed 48 +/- 66 days after acute MI, and 10 other risk variables were also evaluated. The end points were prospectively defined as sudden cardiac death or life-threatening arrhythmic events. RESULTS: During a follow-up of 32 +/- 14 months, 38 patients (3.7%) died of nonarrhythmic causes and were not considered for analysis. Of the 1,003 evaluable patients, 18 (1.8%) reached an end point. Microvolt TWA was positive in 169 patients (17%), negative in 747 (74%), and indeterminate in 87 (9%). A positive microvolt TWA test, nonsustained ventricular tachycardia, and ventricular late potentials were predictors of events, and percutaneous coronary intervention decreased the risk rate. On multivariate analysis, a positive microvolt TWA test was the most significant predictor, with a hazard ratio of 19.7 (p < 0.0001). This marker had the highest sensitivity and negative predictive value for events. CONCLUSIONS: In patients with preserved cardiac function, the incidence of indeterminate results of microvolt TWA is low, and a positive test result is associated with arrhythmic events. Microvolt TWA could be used for risk stratification in this low-risk population.
OBJECTIVES: We conducted a collaborative cohort study to evaluate the predictive power of microvolt T-wave alternans (TWA) in patients with preserved left ventricular ejection fraction (LVEF) after myocardial infarction (MI). BACKGROUND: There is little information available about the prognostic value of risk stratification markers in this population. Although these patients have a relatively good prognosis, identifying high-risk patients is important in clinical practice. METHODS: This study enrolled 1,041 post-MI patients with an LVEF > or =40% (average 55 +/- 10%). Microvolt TWA testing was performed 48 +/- 66 days after acute MI, and 10 other risk variables were also evaluated. The end points were prospectively defined as sudden cardiac death or life-threatening arrhythmic events. RESULTS: During a follow-up of 32 +/- 14 months, 38 patients (3.7%) died of nonarrhythmic causes and were not considered for analysis. Of the 1,003 evaluable patients, 18 (1.8%) reached an end point. Microvolt TWA was positive in 169 patients (17%), negative in 747 (74%), and indeterminate in 87 (9%). A positive microvolt TWA test, nonsustained ventricular tachycardia, and ventricular late potentials were predictors of events, and percutaneous coronary intervention decreased the risk rate. On multivariate analysis, a positive microvolt TWA test was the most significant predictor, with a hazard ratio of 19.7 (p < 0.0001). This marker had the highest sensitivity and negative predictive value for events. CONCLUSIONS: In patients with preserved cardiac function, the incidence of indeterminate results of microvolt TWA is low, and a positive test result is associated with arrhythmic events. Microvolt TWA could be used for risk stratification in this low-risk population.
Authors: Faisal M Merchant; Takanori Ikeda; Roberto F E Pedretti; Jorge A Salerno-Uriarte; Theodore Chow; Paul S Chan; Cheryl Bartone; Stefan H Hohnloser; Richard J Cohen; Antonis A Armoundas Journal: Heart Rhythm Date: 2012-03-08 Impact factor: 6.343
Authors: Leonardo Calò; Tiziana De Santo; Francesca Nuccio; Luigi Sciarra; Lucia De Luca; Lorenza Mangoni di S Stefano; Enrico Piroli; Lorenzo Zuccaro; Marco Rebecchi; Ermenegildo de Ruvo; Ernesto Lioy Journal: Ann Noninvasive Electrocardiol Date: 2011-10 Impact factor: 1.468
Authors: Faisal M Merchant; Hui Zheng; Thomas Bigger; Richard Steinman; Takanori Ikeda; Roberto F E Pedretti; Jorge A Salerno-Uriarte; Catherine Klersy; Paul S Chan; Cheryl Bartone; Stefan H Hohnloser; Jeremy N Ruskin; Antonis A Armoundas Journal: Am Heart J Date: 2013-09-18 Impact factor: 4.749