title: Atrial function as a guide to timing of intervention in mitral valve prolapse with mitral regurgitation.
abstract: OBJECTIVE
  The purpose of this study was to determine the clinical utility of left atrial (LA) functional indexes in patients with mitral valve prolapse (MVP) and mitral regurgitation (MR).
  
  
  BACKGROUND
  Timing of surgery for MVP remains challenging. We hypothesized that assessment of LA function may provide diagnostic utility in these patients.
  
  
  METHODS
  We studied 192 consecutive patients in sinus rhythm with MVP, classified into 3 groups: moderate or less MR (MOD group, n = 54); severe MR without surgical indication (SEV group, n = 52); and severe MR with ≥1 surgical indication (SURG group, n = 86). Comparison was made with 50 control patients. Using 2D speckle imaging, average peak contractile, conduit, and reservoir atrial strain was recorded. Using Simpson's method we recorded maximal left atrial volume (LAVmax) and minimal left atrial volume (LAVmin), from which the total left atrial emptying fraction (TLAEF) was derived: (LAVmax-LAVmin)/LAVmax × 100%.
  
  
  RESULTS
  TLAEF was similar in the MOD and control groups (61% vs. 57%; p = NS), was reduced in the SEV group (55%; p < 0.001 vs. control group), and markedly lower in the SURG group (40%; p < 0.001 vs. other groups). Reservoir strain demonstrated a similar pattern. Contractile strain was similarly reduced in the MOD and SEV groups (MOD 15%; SEV 14%; p = NS; both p < 0.05 vs. control group 20%) and further reduced in the SURG group (8%; p < 0.001 vs. other groups). By multivariate analysis, TLAEF (odds ratio [OR]: 0.78; p < 0.001), reservoir strain (OR: 0.91; p = 0.028), and contractile strain (OR: 0.86; p = 0.021) were independent predictors of severe MR requiring surgery. Using receiver-operating characteristic analysis, TLAEF <50% demonstrated 91% sensitivity and 92% specificity for predicting MVP with surgical indication (area under the curve: 0.96; p < 0.001).
  
  
  CONCLUSIONS
  We report the changes in left atrial function in humans with MVP and the relationship of LA dysfunction to clinical indications for mitral valve surgery. We propose that the findings support the utility of quantitative assessment of atrial function by echocardiography as an additional tool to guide the optimum timing of surgery for MVP.
authors: Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom. Electronic address: liamring@doctors.org.uk.
authors: Liam
authors: L
authors: Ring
authors: Papworth Hospital NHS Foundation Trust, Papworth Everard, United Kingdom.
authors: Bushra S
authors: BS
authors: Rana
authors: Papworth Hospital NHS Foundation Trust, Papworth Everard, United Kingdom.
authors: Francis C
authors: FC
authors: Wells
authors: Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom.
authors: Anna C
authors: AC
authors: Kydd
authors: Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom.
authors: David P
authors: DP
authors: Dutka
mesh_terms: D000328:Adult; D000368:Aged; D019540:Area Under Curve; D016279:Atrial Function, Left; D006348:Cardiac Surgical Procedures; D016009:Chi-Square Distribution; D015150:Echocardiography, Doppler; D005260:Female; D006801:Humans; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery; D008945:Mitral Valve Prolapse / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery; D015999:Multivariate Analysis; D009200:Myocardial Contraction; D016017:Odds Ratio; D018579:Patient Selection; D011237:Predictive Value of Tests; D012372:ROC Curve; D012307:Risk Factors; D012720:Severity of Illness Index; D061665:Time-to-Treatment
keywords: atrial function; mitral valve prolapse; mitral valve surgery