title: Functional and prognostic implications of left ventricular contractile reserve in patients with asymptomatic severe mitral regurgitation.
abstract: OBJECTIVE
  To evaluate contractile reserve (CR) determined by exercise echocardiography in predicting clinical outcome and left ventricular (LV) function in asymptomatic severe mitral regurgitation (MR).
  
  
  METHODS
  Cohort study.
  
  
  METHODS
  Regional cardiac centre.
  
  
  METHODS
  LV volumes and ejection fraction (EF) were measured at rest and after stress in 71 patients with isolated MR. During follow up (mean (SD) 3 (1) years), EF and functional capacity were serially assessed and cardiac events (cardiac death, heart failure, and new atrial fibrillation) were documented.
  
  
  RESULTS
  CR was present in 45 patients (CR+) and absent in 26 patients (CR-). Age, resting LV dimensions, EF, and MR severity were similar in both groups. Mitral surgery was performed in 19 of 45 (42%) CR+ patients and 22 of 26 (85%) CR- patients. In patients undergoing surgery, CR was an independent predictor of follow up EF (p = 0.006) and postoperative LV dysfunction (EF < 50%) persisted in five patients, all in the CR- group. Event-free survival was lower in surgically treated patients without CR (p = 0.03). In medically treated patients, follow up EF was preserved in those with intact CR but progressively deteriorated in patients without CR, in whom functional capacity also deteriorated.
  
  
  CONCLUSIONS
  Evaluation of CR by exercise echocardiography may be useful for risk stratification and may help to optimise the timing of surgery in asymptomatic severe MR.
authors.affiliation: University of Queensland, Brisbane, Australia.
authors.forename: R
authors.initials: R
authors.lastname: Lee
authors.forename: B
authors.initials: B
authors.lastname: Haluska
authors.forename: D Y
authors.initials: DY
authors.lastname: Leung
authors.forename: C
authors.initials: C
authors.lastname: Case
authors.forename: J
authors.initials: J
authors.lastname: Mundy
authors.forename: T H
authors.initials: TH
authors.lastname: Marwick
mesh_terms: D002908:Chronic Disease; D015331:Cohort Studies; D004452:Echocardiography / Q000379:methods; D025401:Echocardiography, Stress / Q000379:methods; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000503:physiopathology* / Q000601:surgery; D011184:Postoperative Period; D011379:Prognosis; D013318:Stroke Volume / Q000502:physiology; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology*