title: Predictors and outcomes of "super-response" to cardiac resynchronization therapy.
abstract: BACKGROUND
  Cardiac resynchronization therapy (CRT) has been shown to improve heart failure (HF) symptoms and survival. We hypothesized that a greater improvement in left-ventricular ejection fraction (LVEF) after CRT is associated with greater survival benefit.
  
  
  RESULTS
  In 693 patients across 2 international centers, the improvement in LVEF after CRT was determined. Patients were grouped as non-/modest-, moderate-, or super-responders to CRT, defined as an absolute change in LVEF of ≤5%, 6-15%, and >15%, respectively. Changes in New York Heart Association (NYHA) functional class and left ventricular end-diastolic dimension (LVEDD) were assessed for each group. There were 395 non-/modest-, 186 moderate-, and 112 super-responders. Super-responders were more likely to be female and to have nonischemic cardiomyopathy, lower creatinine, and lower pulmonary artery systolic pressure than non-/modest- and moderate-responders. Super-responders were also more likely to have lower LVEF than non-/modest-responders. There was no difference in NYHA functional class, mitral regurgitation grade, or tricuspid regurgitation grade between groups. Improvement in NYHA functional class (-0.9 ± 0.9 vs -0.4 ± 0.8 [P < .001] and -0.6 ± 0.8 [P = .02]) and LVEDD (-8.7 ± 9.9 mm vs -0.5 ± 5.0 and -2.4 ± 5.8 mm [P < .001 for both]) was greatest in super-responders. Kaplan-Meier survival analysis revealed that super-responders achieved better survival compared with non-/modest- (P < .001) and moderate-responders (P = .049).
  
  
  CONCLUSIONS
  Improvement in HF symptoms and survival after CRT is proportionate to the degree of improvement in LV systolic function. Super-response is more likely in women, those with nonischemic substrate, and those with lower pulmonary artery systolic pressure.
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota.
authors.forename: Ammar M
authors.initials: AM
authors.lastname: Killu
authors.affiliation: Davidai Arrhythmia Center, Leviev Heart Center, Sheba Medical Center, Tel Hashomer, Israel.
authors.forename: Avishay
authors.initials: A
authors.lastname: Grupper
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Friedman
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota.
authors.forename: Brian D
authors.initials: BD
authors.lastname: Powell
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota.
authors.forename: Samuel J
authors.initials: SJ
authors.lastname: Asirvatham
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota.
authors.forename: Raul E
authors.initials: RE
authors.lastname: Espinosa
authors.affiliation: Davidai Arrhythmia Center, Leviev Heart Center, Sheba Medical Center, Tel Hashomer, Israel.
authors.forename: David
authors.initials: D
authors.lastname: Luria
authors.affiliation: Davidai Arrhythmia Center, Leviev Heart Center, Sheba Medical Center, Tel Hashomer, Israel.
authors.forename: Guy
authors.initials: G
authors.lastname: Rozen
authors.affiliation: Davidai Arrhythmia Center, Leviev Heart Center, Sheba Medical Center, Tel Hashomer, Israel.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Buber
authors.affiliation: Cardiovascular Medicine, Mackay Memorial Hospital, Taipei, Taiwan.
authors.forename: Ying-Hsiang
authors.initials: YH
authors.lastname: Lee
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota.
authors.forename: Tracy
authors.initials: T
authors.lastname: Webster
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota.
authors.forename: Kelly L
authors.initials: KL
authors.lastname: Brooke
authors.affiliation: Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota.
authors.forename: David O
authors.initials: DO
authors.lastname: Hodge
authors.affiliation: Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota.
authors.forename: Heather J
authors.initials: HJ
authors.lastname: Wiste
authors.affiliation: Davidai Arrhythmia Center, Leviev Heart Center, Sheba Medical Center, Tel Hashomer, Israel.
authors.forename: Michael
authors.initials: M
authors.lastname: Glikson
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota. Electronic address: ycha@mayo.edu.
authors.forename: Yong-Mei
authors.initials: YM
authors.lastname: Cha
mesh_terms: D000368:Aged; D058406:Cardiac Resynchronization Therapy / Q000401:mortality / Q000639:trends*; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000175:diagnosis* / Q000401:mortality / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D013318:Stroke Volume / Q000502:physiology*; D015996:Survival Rate / Q000639:trends; D016896:Treatment Outcome
keywords: Cardiac resynchronization; ICD; heart failure; pacemaker; treatment