title: The clinical outcome of cardiac resynchronization therapy in post-surgical valvular cardiomyopathy.
abstract: OBJECTIVE
  Trials have shown that cardiac resynchronization therapy (CRT) is effective in patients with 'non-ischaemic cardiomyopathy'. Patients with post-surgical valvular cardiomyopathy (PSVCM) have been excluded from such trials. We sought to compare the clinical outcome of CRT in patients with PSVCM, idiopathic dilated cardiomyopathy (IDCM), or ischaemic cardiomyopathy (ICM).
  
  
  RESULTS
  Clinical events and response to CRT were quantified in 556 patients (PSVCM = 38; IDCM = 165; ICM = 353) over 4.52 years [median, inter-quartile range (IQR): 4.42]. Response to CRT was defined as survival for ≥1 year free of hospitalizations plus improvement by ≥1 NYHA class or ≥25% in 6-min walking distance. Cardiac resynchronization therapy was initiated at 5.86 years (median, IQR: 9.86) after aortic valve replacement (73.7%) or mitral valve replacement/repair (44.7%). Compared with PSVCM, IDCM was associated with a lower total mortality [hazards ratio, HR: 0.54 (95% confidence interval, CI 0.34-0.84)], cardiac mortality [HR: 0.43 (95% CI 0.26-0.70)], and total mortality or major adverse cardiovascular events [HR: 0.57 (95% CI 0.37-0.87)], independent of known confounders. Compared with PSVCM, ICM was associated with a similar risk of death from pump failure [HR: 0.83 (95% CI 0.50-1.37)] and IDCM was associated with a lower risk [HR: 0.46 (95% CI 0.26-0.82)]. Response to CRT was similar across the groups.
  
  
  CONCLUSIONS
  Compared with IDCM, PSVCM was associated with a worse outcome after CRT. Outcomes from PSVCM were similar to ICM. These findings indicate that PSVCM behaves very differently to IDCM after CRT.
authors.affiliation: Aston Medical Research Institute, Aston Medical School, Aston Triangle, Birmingham, West Midlands B4 7ET, UK f.leyva@aston.ac.uk.
authors.forename: Francisco
authors.initials: F
authors.lastname: Leyva
authors.affiliation: Centre for Cardiovascular Sciences, University of Birmingham, Birmingham, UK.
authors.forename: Fraz
authors.initials: F
authors.lastname: Umar
authors.affiliation: Centre for Cardiovascular Sciences, University of Birmingham, Birmingham, UK.
authors.forename: Robin J
authors.initials: RJ
authors.lastname: Taylor
authors.affiliation: Centre for Cardiovascular Sciences, University of Birmingham, Birmingham, UK.
authors.forename: Richard P
authors.initials: RP
authors.lastname: Steeds
authors.affiliation: Norwich Medical School, University of East Anglia, Norwich, UK.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Frenneaux
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve / Q000601:surgery; D058406:Cardiac Resynchronization Therapy / Q000009:adverse effects; D006348:Cardiac Surgical Procedures; D009202:Cardiomyopathies / Q000145:classification / Q000401:mortality* / Q000628:therapy*; D017147:Defibrillators, Implantable / Q000009:adverse effects*; D004452:Echocardiography; D004868:Equipment Failure / Q000706:statistics & numerical data*; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000628:therapy*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000601:surgery; D015999:Multivariate Analysis; D016016:Proportional Hazards Models; D012307:Risk Factors; D013997:Time Factors; D061665:Time-to-Treatment; D006113:United Kingdom
keywords: Aortic valve replacement; Cardiac resynchronization therapy; Mitral valve replacement; Prognosis; Valvular cardiomyopathy