Biomechanical and echocardiographic characterization of flail mitral leaflet due to myxomatous disease: further evidence for early surgical intervention.
BACKGROUND
Flail mitral leaflet (FML) is a common complication of mitral valve prolapse, often leading to severe mitral regurgitation (MR) and left ventricular dysfunction. In the absence of timely surgical correction, survival is significantly impaired. Early recognition of FML and identification of risk factors is important because early intervention increases the chances of survival.


METHODS
We studied 123 patients undergoing mitral valve surgery for severe MR caused by myxomatous disease. Chart review, echocardiography, and tensile testing were performed.


RESULTS
Thirty-eight patients had FML, and 85 patients had non-flail mitral leaflet (non-FML). Patients with FML were younger (53.7 +/- 1.8 vs 59.3 +/- 1.4 years, P =.02), had more severe MR (3.89 +/- 0.04 vs 3.76 +/- 0.04, P =.02), were less likely to be in New York Heart Association class III or IV heart failure (5% vs 20%, P =.037), and were less likely to have bileaflet mitral valve prolapse (5% vs 38%, P <.001) than non-FML patients. Valve tissue from patients with FML had less stiff chordae (23.5 +/- 3.6 vs 59.1 +/- 11.7 Mpa, P =.006) that tended to have a lower failure stress (3.8 +/- 0.9 vs 9.6 +/- 2.2 Mpa, P =.07) and had more extensible leaflets (56.4% +/- 7.9% vs 42.9% +/- 2.7% strain, P =.04) compared with that of non-FML patients.


CONCLUSIONS
The development of FML may result from intrinsic tissue abnormalities and is associated with a distinct subset of the myxomatous population. Identification of such clinical characteristics in this population and knowledge of an implicit mechanical abnormality of valve tissue may further the argument for early surgical correction.
Mills
William R
WR
Department of Cardiology, Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA.
Barber
J Edward
JE
Ratliff
Norman B
NB
Cosgrove
Delos M
DM
Vesely
Ivan
I
Griffin
Brian P
BP
D002815:Chordae Tendineae / Q000000981:diagnostic imaging / Q000473:pathology; D017548:Echocardiography, Transesophageal; D005260:Female; D006349:Heart Valve Diseases / Q000000981:diagnostic imaging / Q000209:etiology* / Q000473:pathology; D019918:Heart Valve Prosthesis Implantation; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging / Q000473:pathology*; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging / Q000209:etiology / Q000601:surgery; D008945:Mitral Valve Prolapse / Q000150:complications* / Q000000981:diagnostic imaging / Q000601:surgery; D012307:Risk Factors; D012422:Rupture, Spontaneous / Q000209:etiology