title: Small left atrium and mild mitral regurgitation predict super-response to cardiac resynchronization therapy.
abstract: OBJECTIVE
  Cardiac resynchronization therapy (CRT) can result in profound reverse remodelling. The goal of this study was to identify factors predictive of such beneficial response.
  
  
  RESULTS
  Super-response to CRT was defined as normalization or near normalization of left ventricular systolic function without recognized reversible causes of heart failure. In a retrospective study, we compared baseline demographic, electrocardiogram, and echocardiographic characteristics of super-responders (n = 21) with a population of unselected consecutive cardiac CRT patients (Control 1, n = 330) and another sex-, age-, and aetiology-matched control group (Control 2, n = 43). Compared with Control 1, super-responders had significantly smaller left ventricular end-diastolic diameter (65.4 ± 6.4 vs. 73.4 ± 9.3 mm, P = 0.0001), higher ejection fraction (0.25 ± 0.05 vs. 0.22 ± 0.04, P = 0.004), smaller degree of mitral regurgitation (MR; mean value 1.9 ± 0.9 vs. 2.6 ± 0.8, P = <0.0001), and smaller left atrium (LA; 42.8 ± 4.6 vs. 50.0 ± 6.5 mm, P < 0.0001). Septal flash and inter-ventricular mechanical dyssynchrony were both more frequent among super-responders than in Control 2 subjects (93.8 vs. 69.8%; P = 0.01, and 93.8 vs. 62.8%; P = 0.01, respectively). In a multivariate analysis, smaller LA diameter and milder MR remained independent predictors of super-response.
  
  
  CONCLUSIONS
  Super-response to cardiac CRT was associated with less advanced left-sided structural involvement as described by echocardiography. In particular, smaller LA and milder MR were independent predictors of pronounced reverse remodelling.
authors.affiliation: Department of Cardiology, Institute for Clinical and Experimental Medicine, Vídeňská 1958/9, Prague, Czech Republic.
authors.forename: Liliana
authors.initials: L
authors.lastname: Stefan
authors.forename: Kamil
authors.initials: K
authors.lastname: Sedláček
authors.forename: Daniela
authors.initials: D
authors.lastname: Černá
authors.forename: Lukáš
authors.initials: L
authors.lastname: Krýže
authors.forename: Vlastimil
authors.initials: V
authors.lastname: Vančura
authors.forename: Tomáš
authors.initials: T
authors.lastname: Marek
authors.forename: Josef
authors.initials: J
authors.lastname: Kautzner
mesh_terms: D000368:Aged; D058406:Cardiac Resynchronization Therapy; D016009:Chi-Square Distribution; D018153:Czech Republic; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D015999:Multivariate Analysis; D020127:Recovery of Function; D012189:Retrospective Studies; D013318:Stroke Volume; D013997:Time Factors; D016896:Treatment Outcome; D014463:Ultrasonography; D016277:Ventricular Function, Left; D020257:Ventricular Remodeling