Congenital Heart Disease
Validation and Re-Evaluation of a Discriminant
Model Predicting Anatomic Suitability for
Biventricular Repair in Neonates With Aortic Stenosis
Steven D. Colan, MD, Doff B. McElhinney, MD, Elizabeth C. Crawford, RDCS, John F. Keane, MD,
James E. Lock, MD
The purpose of this study was to validate and re-evaluate our previously reported scoring
systems for predicting optimal management in neonates with aortic stenosis (AS).
In 1991, we reported a multivariate discriminant equation and an ordinal scoring system for
predicting which neonates with AS are suitable for biventricular repair and which are better
served by single ventricle management.
Retrospective analysis was performed to: 1) validate our scoring systems in 89 additional
neonates with AS and normal mitral valve area, 2) assess the effects of 5% measurement
variation on predictive scores, 3) evaluate our cohort with the Congenital Heart Surgeons’
Society scoring system, and 4) repeat the discriminant analysis on the basis of all 126 patients.
The original scores each predicted outcome accurately in 68 patients (77%). Minor (5%)
measurement variation changed the outcome predicted by the discriminant equation in 8
patients (9%) and by the threshold system in 13 patients (15%). The most accurate model for
predicting survival with a biventricular circulation among the full cohort is: 10.98 (body
surface area) ? 0.56 (aortic annulus z-score) ? 5.89 (left ventricular to heart long-axis ratio)
? 0.79 (grade 2 or 3 endocardial fibroelastosis) ? 6.78. With a cutoff of ?0.65, outcome was
predicted accurately in 90% of patients.
CONCLUSIONS Both of our original scoring systems are less accurate at predicting outcome than in our
original analysis. Revised discriminant analysis yielded a model similar to our original
equation that was 90% accurate at predicting survival with a biventricular circulation among
neonates with AS and a mitral valve area z-score ??2.
1858–65) © 2006 by the American College of Cardiology Foundation
(J Am Coll Cardiol 2006;47:
Congenital obstruction of left heart structures represents a
spectrum of disease, from isolated obstruction of the aortic
valve or arch to atresia of the aortic and mitral valves (MV)
accompanied by extreme hypoplasia of the entire left heart.
Many patients with anomalies of the left heart complex have
a primary obstructive lesion (e.g., valvar aortic stenosis [AS]) in
association with variable hypoplasia of other left heart
structures. In some of these patients, particularly a subset
with critical AS, the left heart complex is—or borders on
being—insufficiently developed to support the systemic
circulation in a biventricular repair. Although outcomes in
newborns across the spectrum of left heart obstructive
disease continue to improve, it can be challenging to predict
whether patients with a “borderline” left heart are suitable
candidates for biventricular repair (1–14).
In 1991, we performed a retrospective discriminant anal-
ysis in 45 patients ?60 days of age with critical AS (1).
Although we recognized that factors other than anatomic
dimensions were likely important in determining outcome,
we sought to identify anatomic features that limited the
capacity of the left heart complex to support a systemic
cardiac output in a biventricular circulation. We found that
the multivariate equation 14.0 (body surface area [BSA]) ?
0.943 (indexed aortic root diameter) ? 4.78 (left ventricular
[LV] long-axis to heart long-axis ratio [LAR]) ? 0.157
(indexed MV area) ? 12.03 (hereafter, discriminant score)
successfully predicted survival with a biventricular circula-
tion or death/conversion to a functional single ventricle
(SV) circulation in 90% of patients. In addition to this
discriminant score, we developed a simpler ordinal scoring
system on the basis of threshold values (hereafter, threshold
score), such that one point against survival was assessed for
each of the following anatomic measurements below a
threshold value: indexed aortic root diameter, indexed MV
area, LAR, and indexed LV mass. All patients with a
threshold score ?2 died or underwent conversion to a
functional SV circulation, and 92% of patients with a score
In the 14 years since our previous study was published, we
have used these scoring systems to guide therapeutic
decision-making in neonates with AS. Although treatment
has not been stratified strictly according to either scoring
system, patients with significant hypoplasia (z-score ??2)
of the MV or LV chamber have generally been referred for
univentricular palliation. To assess the validity of our
scoring systems, we reviewed outcomes in 89 patients ?60
From the Department of Cardiology, Children’s Hospital, and Department of
Pediatrics, Harvard Medical School, Boston, Massachusetts.
Manuscript received October 20, 2004; revised manuscript received December 2,
2005, accepted December 13, 2005.
Journal of the American College of Cardiology
© 2006 by the American College of Cardiology Foundation
Published by Elsevier Inc.
Vol. 47, No. 9, 2006
support a systemic cardiac output in a biventricular circula-
tion and to aid in the complex task of deciding on the initial
treatment course in neonates with AS and borderline left
Reprint requests and correspondence: Dr. Steven D. Colan,
Department of Cardiology, Children’s Hospital, 300 Longwood
Avenue, Boston, Massachusetts 02115. E-mail: steven.colan@
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JACC Vol. 47, No. 9, 2006
May 2, 2006:1858–65
Colan et al.
Predictors of Biventricular Repair in Critical AS