title: Right ventricular dysfunction is a predictor of non-response and clinical outcome following cardiac resynchronization therapy.
abstract: BACKGROUND
  Cardiac resynchronization therapy (CRT) is an established treatment in advanced heart failure (HF). However, an important subset does not derive a significant benefit. Despite an established predictive role in HF, the significance of right ventricular (RV) dysfunction in predicting clinical benefit from CRT remains unclear. We investigated the role of RV function, assessed by cardiovascular magnetic resonance (CMR), in predicting response to and major adverse clinical events in HF patients undergoing CRT.
  
  
  METHODS
  Sixty consecutive patients were evaluated with CMR prior to CRT implantation in a tertiary cardiac centre. The primary end-point was a composite of death from any cause or unplanned hospitalization for a major cardiovascular event. The secondary end-point was response to therapy, defined as improvement in left ventricular ejection fraction ≥ 5% on echocardiography at one year.
  
  
  RESULTS
  Eighteen patients (30%) met the primary end-point over a median follow-up period of 26 months, and 27 out of 56 patients (48%) were considered responders to CRT. On time-to-event analysis, only atrial fibrillation (HR 2.6, 95% CI 1.02-6.84, p = 0.047) and RV dysfunction, either by a reduced right ventricular ejection fraction-RVEF (HR 0.96, 95% CI 0.94-0.99, p = 0.006) or tricuspid annular plane systolic excursion-TAPSE (HR 0.88, 95% CI, 0.80-0.96, p = 0.006), were significant predictors of adverse events. On logistic regression analysis, preserved RVEF (OR 1.05, 95% CI 1.01-1.09, p = 0.01) and myocardial scar burden (OR 0.90, 95% CI 0.83-0.96, p = 0.004) were the sole independent predictors of response to CRT. Patients with marked RV dysfunction (RVEF < 30%) had a particularly low response rate (18.2%) to CRT.
  
  
  CONCLUSIONS
  Right ventricular function is an important predictor of both response to CRT and long-term clinical outcome. Routine assessment of the right ventricle should be considered in the evaluation of patients for CRT.
authors: CMR Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK.
authors: Francisco
authors: F
authors: Alpendurada
authors: Kaushik
authors: K
authors: Guha
authors: Rakesh
authors: R
authors: Sharma
authors: Tevfik F
authors: TF
authors: Ismail
authors: Amy
authors: A
authors: Clifford
authors: Winston
authors: W
authors: Banya
authors: Raad H
authors: RH
authors: Mohiaddin
authors: Dudley J
authors: DJ
authors: Pennell
authors: Martin R
authors: MR
authors: Cowie
authors: Theresa
authors: T
authors: McDonagh
authors: Sanjay K
authors: SK
authors: Prasad
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D058406:Cardiac Resynchronization Therapy / Q000009:adverse effects / Q000401:mortality; D005260:Female; D006333:Heart Failure / Q000150:complications / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D053208:Kaplan-Meier Estimate; D016015:Logistic Models; D008131:London; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D018579:Patient Selection; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D018497:Ventricular Dysfunction, Right / Q000150:complications / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D016277:Ventricular Function, Left; D016278:Ventricular Function, Right