title: Impact of the right ventricular lead position on clinical outcome and on the incidence of ventricular tachyarrhythmias in patients with CRT-D.
abstract: BACKGROUND
  Data on the impact of right ventricular (RV) lead location on clinical outcome and ventricular tachyarrhythmias in cardiac resynchronization therapy with defibrillator (CRT-D) patients are limited.
  
  
  OBJECTIVE
  To evaluate the impact of different RV lead locations on clinical outcome in CRT-D patients enrolled in the Multicenter Automatic Defibrillator Implantation Trial-Cardiac Resynchronization Therapy trial.
  
  
  METHODS
  We investigated 742 of 1089 CRT-D patients (68%) with adjudicated RV lead location enrolled in the Multicenter Automatic Defibrillator Implantation Trial-Cardiac Resynchronization Therapy trial to evaluate the impact of RV lead location on cardiac events. The primary end point was heart failure or death; secondary end points included ventricular tachycardia (VT), ventricular fibrillation (VF), or death and VT or VF alone.
  
  
  RESULTS
  Eighty-six patients had the RV lead positioned at the RV septal or right ventricular outflow tract region, combined as nonapical RV group, and 656 patients had apical RV lead location. There was no difference in the primary end point in patients with nonapical RV lead location versus those with apical RV lead location (hazard ratio [HR] 0.98; 95% confidence interval [CI] 0.54-1.80; P = .983). Echocardiographic response to CRT-D was comparable across RV lead location groups (P > .05 for left ventricular end-diastolic volume, left ventricular end-systolic volume, and left atrial volume percent change). However, nonapical RV lead location was associated with significantly higher risk of VT/VF/death (HR 2.45; 95% CI 1.36-4.41; P = .003) and VT/VF alone (HR 2.52; 95% CI 1.36-4.65; P = .002), predominantly in the first year after device implantation. Results were consistent in patients with left bundle branch block.
  
  
  CONCLUSIONS
  In CRT-D patients, there is no benefit of nonapical RV lead location in clinical outcome or echocardiographic response. Moreover, nonapical RV lead location is associated with an increased risk of ventricular tachyarrhythmias, particularly in the first year after device implantation.
authors: University of Rochester Medical Center, Rochester, New York; Semmelweis University, Heart Center, Budapest, Hungary, and Brigham and Women's Hospital, Boston, Massachusetts. Electronic address: valentina.kutyifa@heart.rochester.edu.
authors: Valentina
authors: V
authors: Kutyifa
authors: Poul Erik
authors: PE
authors: Bloch Thomsen
authors: David T
authors: DT
authors: Huang
authors: Spencer
authors: S
authors: Rosero
authors: Christine
authors: C
authors: Tompkins
authors: Christian
authors: C
authors: Jons
authors: Scott
authors: S
authors: McNitt
authors: Bronislava
authors: B
authors: Polonsky
authors: Amil
authors: A
authors: Shah
authors: Bela
authors: B
authors: Merkely
authors: Scott D
authors: SD
authors: Solomon
authors: Arthur J
authors: AJ
authors: Moss
authors: Wojciech
authors: W
authors: Zareba
authors: Helmut U
authors: HU
authors: Klein
mesh_terms: D002423:Cause of Death / Q000639:trends; D017147:Defibrillators, Implantable; D003718:Denmark / Q000453:epidemiology; D004452:Echocardiography; D005260:Female; D005471:Fluoroscopy; D005500:Follow-Up Studies; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D013902:Radiography, Thoracic; D013318:Stroke Volume; D015996:Survival Rate / Q000639:trends; D017180:Tachycardia, Ventricular / Q000453:epidemiology / Q000503:physiopathology / Q000628:therapy*; D013997:Time Factors; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology
keywords: A; CI; CRT; CRT-D; Cardiac resynchronization therapy; Clinical outcome; Echocardiography; HF; HR; ICD; LAV; LBBB; LV; LVEDV; LVEF; LVESV; MADIT-CRT; Multicenter Automatic Defibrillator Implantation Trial–Cardiac Resynchronization Therapy; Nonapical RV lead position; RV; RVOT; V; VF; VT; Ventricular arrhythmia; atrial; cardiac resynchronization therapy; cardiac resynchronization therapy with defibrillator; confidence interval; hazard ratio; heart failure; implantable cardioverter-defibrillator; left atrial volume; left bundle branch block; left ventricular; left ventricular ejection fraction; left ventricular end-diastolic volume; left ventricular end-systolic volume; right ventricular; right ventricular outflow tract; ventricular; ventricular fibrillation; ventricular tachycardia