Independent factors associated with outcomes of parachute mitral valve in 84 patients.
BACKGROUND
Parachute mitral valve (PMV) is defined as a unifocal attachment of the mitral valve chordae to a single or dominant papillary muscle and may cause subvalvar obstruction. We sought to determine factors associated with outcomes.


RESULTS
Patients (n=84; 64% male) who presented between 1977 and 2001 at a median age of 3 days (range, birth to 5.4 years) were assessed with PMV (without atrioventricular septal defect). Associated cardiac anomalies in 99% included aortic coarctation in 68%, atrial septal defect in 54%, ventricular septal defect in 46%, aortic valve stenosis in 32%, subaortic stenosis in 20%, and left ventricular hypoplasia in 19%, with complex anomalies in 14%. Noncardiac anomalies were noted in 32%. Survival (n=18 deaths) was 82% at 1 year and 79% at 10 years, with independent risk factors including left ventricular hypoplasia (P<0.001) and atrial septal defect (P<0.003). Freedom from surgical mitral valvotomy (n=11 patients) was 95% at age 6 months and 80% at 10 years, with independent risk factors including the absence of aortic coarctation (P<0.02) and the presence of subaortic stenosis (P<0.04). There was no significant increase in mean gradient of the PMV over time, but higher gradient was independently associated with the presence of supravalvar mitral stenosis (P<0.001), absence of atrial septal defect (P<0.04), presence of ventricular septal defect (P<0.02), and subsequent mitral valvotomy (P<0.01).


CONCLUSIONS
Outcomes for patients with PMV are dependent on the spectrum of associated cardiac lesions. The degree of mitral valve obstruction remains stable, and the majority will not require valvotomy.
Schaverien
Mark V
MV
Division of Cardiology, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.
Freedom
Robert M
RM
McCrindle
Brian W
BW
D000015:Abnormalities, Multiple / Q000453:epidemiology; D002423:Cause of Death; D002675:Child, Preschool; D002815:Chordae Tendineae / Q000002:abnormalities*; D005260:Female; D006330:Heart Defects, Congenital / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000601:surgery; D006333:Heart Failure / Q000209:etiology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D015993:Life Tables; D008297:Male; D008943:Mitral Valve / Q000002:abnormalities* / Q000601:surgery; D008946:Mitral Valve Stenosis / Q000151:congenital* / Q000000981:diagnostic imaging / Q000601:surgery / Q000628:therapy; D010210:Papillary Muscles / Q000002:abnormalities*; D011379:Prognosis; D016016:Proportional Hazards Models; D012307:Risk Factors; D016019:Survival Analysis; D016896:Treatment Outcome; D014463:Ultrasonography