T-peak to T-end interval for prediction of ventricular tachyarrhythmia and mortality in a primary prevention population with systolic cardiomyopathy

Heart Rhythm. 2015 Aug;12(8):1789-97. doi: 10.1016/j.hrthm.2015.04.035. Epub 2015 May 18.

Abstract

Background: The electrocardiographic T-wave peak to T-wave end interval (Tpe) correlates with dispersion of ventricular repolarization (DVR). Increased DVR increases propensity toward electrical reentry that can cause ventricular tachyarrhythmia. The baseline rate-corrected Tpe (Tpec) has been shown to predict ventricular tachyarrhythmia and death in multiple patient populations but not among cardiomyopathic patients undergoing insertion of an implantable cardioverter-defibrillator (ICD) for primary prevention.

Objective: The purpose of this study was to assess the risk stratification ability of the Tpec in patients with systolic cardiomyopathy without prior ventricular tachyarrhythmia (ie, the primary prevention population).

Methods: We performed prospective follow-up of 305 patients (73% men; left ventricular ejection fraction [LVEF] 23 ± 7%) with LVEF ≤35% and an ICD implanted for primary prevention. Baseline ECGs were analyzed with automated algorithms. Endpoints were ventricular tachycardia (VT)/ventricular fibrillation (VF), death, and a combined endpoint of VT/VF or death, assessed by device follow-up and Social Security Death Index query.

Results: The average Tpec was 107 ± 22 ms. During device clinic follow-up of 31 ± 23 months, 82 patients (27%) had appropriate ICD therapy for VT/VF, and during mortality follow-up of 49 ± 21 months, 91 patients (30%) died. On univariable analysis, Tpec predicted VT/VF, death, and the combined endpoint of VT/VF or death (P < .05 for each endpoint). Multivariable analysis included univariable predictors among demographics, clinical data, laboratory data, medications used, and electrocardiography parameters. After correction, Tpec remained predictive of VT/VF (hazard ratio [HR] per 10-ms increase 1.16, P = .009), all-cause mortality (HR per 10 ms 1.13, P = .05), and the combined endpoint (HR per 10 ms 1.17, P = .001).

Conclusion: Tpec independently predicts both VT/VF and overall mortality in patients with systolic dysfunction and ICDs implanted for primary prevention.

Keywords: Death; Electrocardiography; T-peak to T-end; Ventricular tachyarrhythmia.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Cardiomyopathies / complications*
  • Cardiomyopathies / mortality
  • Cardiomyopathies / physiopathology
  • Defibrillators, Implantable*
  • Electrocardiography*
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Middle Aged
  • Predictive Value of Tests
  • Primary Prevention / methods*
  • Proportional Hazards Models
  • Prospective Studies
  • Tachycardia, Ventricular / etiology
  • Tachycardia, Ventricular / physiopathology*
  • Tachycardia, Ventricular / therapy
  • Ventricular Fibrillation / etiology
  • Ventricular Fibrillation / physiopathology*
  • Ventricular Fibrillation / therapy