Functional and intrinsic mitral valve (MV) abnormalities are common in hypertrophic
cardiomyopathy (HCM); however, morphologic characteristics constituting indications
for surgical intervention are incompletely defined. This study was conducted to define
the echocardiographic features of MV pathology in patients with HCM and relate these
to repairability of the MV, MV procedures performed, durability of repair, and survival.
From 1986 to 2003, 851 patients with HCM underwent operation, and 115 had a concomitant
MV procedure. Detailed analysis of their 784 transthoracic and transesophageal echocardiograms,
performed intraoperatively and postoperatively, was conducted. Outcomes were assessed
by cross-sectional follow-up.
Sixty-seven patients (58%) underwent MV repair, and 48 (42%) had MV replacement. The
mean left ventricular outflow tract peak gradient was 70 +/- 50 mm Hg. Systolic anterior
motion was present in 95%. Valve abnormalities were degenerative in 36 (31%), myxomatous
in 23 (20%), papillary muscle in 23 (20%), restrictive chordal in 22 (19%), restrictive
leaflet in 80 (70%), and long leaflet in 64 (56%). Patients undergoing MV repair had
higher prevalence of long leaflets and degenerative MV pathology. The anterior mitral
leaflet was 3.0 +/- 0.49 cm in the repair group vs 2.5 +/- 0.40 cm in the replacement
group (p = 0.0001). MV replacement patients were older, more symptomatic, and had
more renal dysfunction and lower hematocrits. By 3 years, 91% of patients with a repair
were free of reoperation.
Intrinsic MV pathology is frequently observed in HCM patients with symptomatic obstruction
who undergo myectomy. Echocardiography can identify MV features predictive of successful
valve repair. Repair, although durable, is feasible in only about half of patients.