title: Determinants of regurgitant volume in mitral regurgitation: contrasting effect of similar effective regurgitant orifice area in functional and organic mitral regurgitation.
abstract: BACKGROUND
  Quantitative assessment of the severity of mitral regurgitation (MR) is based on the calculation of the effective regurgitant orifice (ERO), a measure of lesion severity, and of the regurgitant volume (RVol), a measure of left ventricular volume overload. We aimed at evaluating the determinants of RVol in both organic (OMR) and functional mitral regurgitation (FMR).
  
  
  RESULTS
  MR severity was quantitatively assessed using the proximal isovelocity surface area (PISA) method in 240 patients, 142 with OMR and 98 patients with FMR. By definition, ERO and RVol were strongly correlated both in patients with OMR and FMR (both R = 0.90, P < 0.0001) but the slopes of the regression lines were significantly different (P < 0.0001). This difference remained significant in patients with elevated systolic pulmonary artery pressure (SPAP > 40 mmHg, P < 0.0001) but not in patients with normal SPAP (≤40 mmHg, P = 0.09). In multivariate analysis, independent determinants of RVol were ERO (P < 0.0001), MR mechanism (FMR/OMR) (P = 0.0003) and SPAP (P = 0.03). In patients with elevated SPAP, ERO (P < 0.0001), left ventricular ejection fraction (LVEF) (P = 0.03), and MR mechanism (P = 0.03) were independently associated with RVol, whereas in patients with normal SPAP, ERO (P < 0.0001) was the only independent determinant of RVol.
  
  
  CONCLUSIONS
  In the present study, we evaluated the contrasting effect of similar lesion severity in OMR and FMR and showed that similar ERO were associated with lower RVol in FMR compared with OMR. The regurgitant volume is the result of complex interactions of anatomic lesions, LVEF, and SPAP and our results highlight the importance of taking into account these parameters when interpreting RVol values in clinical practice, especially in FMR.
authors.affiliation: Cardiovascular Division, Cardiology Department, AP-HP, Bichat Hospital, 46 rue Henri Huchard, Paris, France.
authors.forename: Andrea
authors.initials: A
authors.lastname: Chiampan
authors.forename: Julien
authors.initials: J
authors.lastname: Nahum
authors.forename: Mohamed
authors.initials: M
authors.lastname: Leye
authors.forename: Johanna
authors.initials: J
authors.lastname: Oziel
authors.forename: Caroline
authors.initials: C
authors.lastname: Cueff
authors.forename: Eric
authors.initials: E
authors.lastname: Brochet
authors.forename: Bernard
authors.initials: B
authors.lastname: Iung
authors.forename: Andrea
authors.initials: A
authors.lastname: Rossi
authors.forename: Alec
authors.initials: A
authors.lastname: Vahanian
authors.forename: David
authors.initials: D
authors.lastname: Messika-Zeitoun
mesh_terms: D016009:Chi-Square Distribution; D005260:Female; D006305:Health Status Indicators; D006352:Heart Ventricles; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging* / Q000473:pathology; D008944:Mitral Valve Insufficiency / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000473:pathology; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D011651:Pulmonary Artery; D012044:Regression Analysis; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D013223:Statistics as Topic; D013318:Stroke Volume; D014463:Ultrasonography; D016277:Ventricular Function, Left