Echocardiographic definition and surgical decision-making in unbalanced atrioventricular septal defect: a Congenital Heart Surgeons' Society multiinstitutional study.
BACKGROUND
Although identification of unbalanced atrioventricular septal defect (AVSD) is obvious when extreme, exact criteria to define the limits of unbalanced are not available. We sought to validate an atrioventricular valve index (AVVI) (left atrioventricular valve area/total atrioventricular valve area, centimeters squared) as a discriminator of balanced and unbalanced forms of complete AVSD and to characterize the association of AVVI with surgical strategies and outcomes.


RESULTS
Diagnostic echocardiograms and hospital records of 356 infants with complete AVSD at 4 Congenital Heart Surgeons' Society (CHSS) institutions (2000-2006) were reviewed and AVVI measured (n=315). Patients were classified as unbalanced if AVVI≤0.4 (right dominant) or ≥0.6 (left dominant). Surgical strategy and outcomes were examined across the range of AVVI. Competing risks analysis until the time of commitment to a surgical strategy examined 4 end states: biventricular repair (BVR), univentricular repair (UVR), pulmonary artery banding (PAB), and death before surgery. A prediction nomogram for surgical strategy based on AVVI was developed. The majority of patients had balanced AVSD (0.4<AVVI<0.6) and underwent BVR. Patients with AVVI<0.19 uniformly underwent UVR. Heterogeneous repair strategies were found when 0.19≤AVVI≤0.39 (UVR and BVR), with a disproportionate number of deaths in this range. AVVI≥0.6 (left dominant) was less common. The proportion of subjects predicted for the end states at 12 months after diagnosis are: BVR, 86%; UVR, 7%; PAB, 1%; death without surgery, 1%; alive without surgery, 5%.


CONCLUSIONS
AVVI effectively characterizes the transition between balanced and unbalanced AVSD with important correlation to anatomic substrate and selected surgical strategy.
Jegatheeswaran
Anusha
A
Labatt Family Heart Centre, The Hospital for Sick Children, Toronto, ON, Canada. anusha.jegatheeswaran@utoronto.ca
Pizarro
Christian
C
Caldarone
Christopher A
CA
Cohen
Meryl S
MS
Baffa
Jeanne M
JM
Gremmels
David B
DB
Mertens
Luc
L
Morell
Victor O
VO
Williams
William G
WG
Blackstone
Eugene H
EH
McCrindle
Brian W
BW
Overman
David M
DM
D018572:Disease-Free Survival; D004452:Echocardiography; D005260:Female; D006345:Heart Septal Defects, Ventricular / Q000175:diagnosis* / Q000000981:diagnostic imaging* / Q000401:mortality / Q000601:surgery*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D012955:Societies, Medical; D015996:Survival Rate; D013903:Thoracic Surgery; D014481:United States