title: T-wave area as biomarker of clinical response to cardiac resynchronization therapy.
abstract: OBJECTIVE
  There is increasing evidence that left bundle branch block (LBBB) morphology on the electrocardiogram is a positive predictor for response to cardiac resynchronization therapy (CRT). We previously demonstrated that the vectorcardiography (VCG)-derived T-wave area predicts echocardiographic CRT response in LBBB patients. In the present study, we investigate whether the T-wave area also predicts long-term clinical outcome to CRT.
  
  
  RESULTS
  This is a retrospective study consisting of 335 CRT recipients. Primary endpoint were the composite of heart failure (HF) hospitalization, heart transplantation, left ventricular assist device implantation or death during a 3-year follow-up period. HF hospitalization and death alone were secondary endpoints. The patient subgroup with a large T-wave area and LBBB 36% reached the primary endpoint, which was considerably less (P < 0.01) than for patients with LBBB and a small T-wave area or non-LBBB patients with a small or large T-wave area (48, 57, and 51%, respectively). Similar differences were observed for the secondary endpoints, HF hospitalization (31 vs. 51, 51, and 38%, respectively, P < 0.01) and death (19 vs. 42, 34, and 42%, respectively, P < 0.01). In multivariate analysis, a large T-wave area and LBBB were the only independent predictors of the combined endpoint besides high creatinine levels and use of diuretics.
  
  
  CONCLUSIONS
  T-wave area may be useful as an additional biomarker to stratify CRT candidates and improve selection of those most likely to benefit from CRT. A large T-wave area may derive its predictive value from reflecting good intrinsic myocardial properties and a substrate for CRT.
authors.affiliation: Cardiac Arrhythmia Service, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA Semmelweis University Heart and Vascular Center, Budapest, Hungary.
authors.forename: Eszter M
authors.initials: EM
authors.lastname: Végh
authors.affiliation: Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht University, P.O. Box 616, 6200MD Maastricht, The Netherlands.
authors.forename: Elien B
authors.initials: EB
authors.lastname: Engels
authors.affiliation: Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht University, P.O. Box 616, 6200MD Maastricht, The Netherlands Department of Cardiology, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands.
authors.forename: Caroline J M
authors.initials: CJ
authors.lastname: van Deursen
authors.affiliation: Semmelweis University Heart and Vascular Center, Budapest, Hungary.
authors.forename: Béla
authors.initials: B
authors.lastname: Merkely
authors.affiliation: Department of Cardiology, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands.
authors.forename: Kevin
authors.initials: K
authors.lastname: Vernooy
authors.affiliation: Cardiac Arrhythmia Service, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Jagmeet P
authors.initials: JP
authors.lastname: Singh
authors.affiliation: Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht University, P.O. Box 616, 6200MD Maastricht, The Netherlands frits.prinzen@maastrichtuniversity.nl.
authors.forename: Frits W
authors.initials: FW
authors.lastname: Prinzen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001145:Arrhythmias, Cardiac / Q000503:physiopathology*; D015415:Biomarkers; D002037:Bundle-Branch Block / Q000503:physiopathology*; D058406:Cardiac Resynchronization Therapy / Q000379:methods*; D058409:Cardiac Resynchronization Therapy Devices; D004452:Echocardiography; D005260:Female; D006333:Heart Failure / Q000401:mortality / Q000628:therapy*; D006760:Hospitalization; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D013318:Stroke Volume; D013997:Time Factors; D016896:Treatment Outcome; D014672:Vectorcardiography / Q000379:methods*
chemical_list: D015415:Biomarkers
keywords: Cardiac resynchronization therapy; Left bundle branch block; Long-term clinical outcome; T wave area; Vectorcardiography