title: Targeted left ventricular lead placement to guide cardiac resynchronization therapy: the TARGET study: a randomized, controlled trial.
abstract: OBJECTIVE
  This study sought to assess the impact of targeted left ventricular (LV) lead placement on outcomes of cardiac resynchronization therapy (CRT).
  
  
  BACKGROUND
  Placement of the LV lead to the latest sites of contraction and away from the scar confers the best response to CRT. We conducted a randomized, controlled trial to compare a targeted approach to LV lead placement with usual care.
  
  
  METHODS
  A total of 220 patients scheduled for CRT underwent baseline echocardiographic speckle-tracking 2-dimensional radial strain imaging and were then randomized 1:1 into 2 groups. In group 1 (TARGET [Targeted Left Ventricular Lead Placement to Guide Cardiac Resynchronization Therapy]), the LV lead was positioned at the latest site of peak contraction with an amplitude of >10% to signify freedom from scar. In group 2 (control) patients underwent standard unguided CRT. Patients were classified by the relationship of the LV lead to the optimal site as concordant (at optimal site), adjacent (within 1 segment), or remote (≥2 segments away). The primary endpoint was a ≥15% reduction in LV end-systolic volume at 6 months. Secondary endpoints were clinical response (≥1 improvement in New York Heart Association functional class), all-cause mortality, and combined all-cause mortality and heart failure-related hospitalization.
  
  
  RESULTS
  The groups were balanced at randomization. In the TARGET group, there was a greater proportion of responders at 6 months (70% vs. 55%, p = 0.031), giving an absolute difference in the primary endpoint of 15% (95% confidence interval: 2% to 28%). Compared with controls, TARGET patients had a higher clinical response (83% vs. 65%, p = 0.003) and lower rates of the combined endpoint (log-rank test, p = 0.031).
  
  
  CONCLUSIONS
  Compared with standard CRT treatment, the use of speckle-tracking echocardiography to the target LV lead placement yields significantly improved response and clinical status and lower rates of combined death and heart failure-related hospitalization. (Targeted Left Ventricular Lead Placement to Guide Cardiac Resynchronization Therapy [TARGET] study); ISRCTN19717943).
authors.affiliation: Papworth Hospital, Cambridge, United Kingdom.
authors.forename: Fakhar Z
authors.initials: FZ
authors.lastname: Khan
authors.forename: Mumohan S
authors.initials: MS
authors.lastname: Virdee
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Palmer
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Pugh
authors.forename: Denis
authors.initials: D
authors.lastname: O'Halloran
authors.forename: Maros
authors.initials: M
authors.lastname: Elsik
authors.forename: Philip A
authors.initials: PA
authors.lastname: Read
authors.forename: David
authors.initials: D
authors.lastname: Begley
authors.forename: Simon P
authors.initials: SP
authors.lastname: Fynn
authors.forename: David P
authors.initials: DP
authors.lastname: Dutka
mesh_terms: D000368:Aged; D058406:Cardiac Resynchronization Therapy / Q000379:methods* / Q000401:mortality*; D058409:Cardiac Resynchronization Therapy Devices; D002423:Cause of Death; D004452:Echocardiography / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000628:therapy*; D006352:Heart Ventricles / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D018570:Risk Assessment; D012720:Severity of Illness Index; D016037:Single-Blind Method; D013318:Stroke Volume; D015996:Survival Rate; D016896:Treatment Outcome; D006113:United Kingdom; D020257:Ventricular Remodeling / Q000502:physiology