Electrocardiographic predictors of sudden and non-sudden cardiac death in patients with ischemic cardiomyopathy

• Published in: Heart & lung Vol. 43; no. 6; pp. 527 - 533
• Main Authors: Al-Zaiti, Salah S., PhD, Fallavollita, James A., MD, Canty, John M., MD, Carey, Mary G., PhD
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.11.2014; Elsevier Science Ltd
• Subjects: Aged; Cardiovascular; Critical Care; Death, Sudden, Cardiac - etiology; Death, Sudden, Cardiac - prevention & control; Defibrillators, Implantable; Electrocardiogram; Electrocardiography; Female; Follow-Up Studies; Heart; Heart attacks; Heart Rate - physiology; Humans; Implantable cardioverter defibrillator; Ischemic cardiomyopathy; Male; Middle Aged; Mortality; Myocardial Ischemia - complications; Patients; Prospective Studies; Pulmonary/Respiratory; Sudden cardiac arrest; Ventricular Function, Left - physiology; Sudden cardiac arrest; Electrocardiogram; Implantable cardioverter defibrillator; Ischemic cardiomyopathy
• ISSN: 0147-9563; 1527-3288
• DOI: 10.1016/j.hrtlng.2014.05.008

Abstract Objective This study evaluated the prognostic value of electrocardiogram (ECG)-based predictors in the primary prevention of sudden cardiac arrest (SCA) among ischemic cardiomyopathy patients with depressed left ventricular ejection fraction (LVEF ≤35%). Background The prediction of cause-specific mortality in high-risk patients offers the potential for targeting specific therapies (i.e., implantable cardioverter-defibrillator [ICD]). Methods Subjects were recruited from the Prediction of Arrhythmic Events with Positron Emission Tomography (PAREPET) study. Continuous Holter 12-lead ECG recordings were obtained at the start of study and used to compute 15 clinically-important ECG abnormalities (e.g., atrial fibrillation). Results Among 197 patients (age 67 ± 11 years, 93% male, mean follow-up 4.1 years) enrolled, 30 (15%) were SCA cases and 35 (18%) cardiac non-sudden deaths (C/NS). In multivariate analysis, only heart-rate-corrected QT interval (QTc) predicted SCA (hazard ratio 2.9 [1.2–7.3]) and only depressed heart rate variability (HRV) predicted C/NS (hazard ratio 5.0 [1.5–17.1]) independent of demographic and clinical parameters. Conclusions Among patients with depressed LVEF, prolonged QTc suggests greater potential benefit from ICD therapy to prevent SCA; depressed HRV suggests potential benefit from bi-ventricular pacing to prevent C/NS.