title: Prolonged total isovolumic time is related to reduced long-axis functional recovery following valve replacement surgery for severe aortic stenosis.
abstract: BACKGROUND
  The left ventricular (LV) long axis (Lax) function is very sensitive in documenting myocardial abnormalities in aortic stenosis (AS). We hypothesized that Lax recovery after aortic valve replacement (AVR) is related to the extent of cavity dyssynchrony measured by total isovolumic time (t-IVT).
  
  
  METHODS
  A consecutive 107 patients (aged 70 ± 7 years, 70 male) with severe AS and Lax impairment were studied. T-IVT was measured before and after AVR. Reduced Lax function and its post-operative recovery were defined as mitral annular plane systolic excursion (MAPSE) ≦10 mm and an increase of MAPSE >10%, respectively.
  
  
  RESULTS
  LV function improved (EF: 43 ± 8 to 48 ± 10%; MAPSE: 7.9 ± 1.0 to 11.0 ± 2.4 mm) and t-IVT shortened (9.7 ± 3.7 to 7.0 ± 2.8s/min, p<0.01 for all) after AVR. Sixty-five (61%) patients had Lax recovery after a median of 32-month follow-up. Univariate predictors were LV size, LA dimensions, the presence of restrictive LV filling and prolonged t-IVT. Only LV end-systolic dimension, restrictive filling and t-IVT (OR 0.61, 95% CI 0.47-0.79, p<0.01) were independent predictors. A pre-operative t-IVT ≦ 9.3s/min was 81% sensitive and 63% specific in predicting Lax recovery (AUC 0.81, p<0.001). The prevalence of CAD or concomitant CABG were similar in 2 patient groups with different t-IVT.
  
  
  CONCLUSIONS
  Lax recovery was evident in the majority of AS patients after AVR. The lower prevalence of Lax recovery seen in patients with prolonged t-IVT suggests that dyssynchrony may play an important role in the process of adverse LV remodeling.
authors.affiliation: Division of Cardiology, Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Yat-Yin
authors.initials: YY
authors.lastname: Lam
authors.forename: Gani
authors.initials: G
authors.lastname: Bajraktari
authors.forename: Per
authors.initials: P
authors.lastname: Lindqvist
authors.forename: Anders
authors.initials: A
authors.lastname: Holmgren
authors.forename: Roberta
authors.initials: R
authors.lastname: Mole
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.forename: Alison
authors.initials: A
authors.lastname: Duncan
authors.forename: Wen-Hong
authors.initials: WH
authors.lastname: Ding
authors.forename: Sergio
authors.initials: S
authors.lastname: Mondillo
authors.forename: John R
authors.initials: JR
authors.lastname: Pepper
authors.forename: Michael Y
authors.initials: MY
authors.lastname: Henein
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001024:Aortic Valve Stenosis / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery; D005260:Female; D019918:Heart Valve Prosthesis Implantation / Q000639:trends; D006801:Humans; D008297:Male; D008875:Middle Aged; D020127:Recovery of Function / Q000502:physiology*; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013318:Stroke Volume / Q000502:physiology*; D013997:Time Factors; D016277:Ventricular Function, Left / Q000502:physiology; D020257:Ventricular Remodeling / Q000502:physiology*