Background: In critical LVOT obstruction, there are few prognostic scores for decision making
between univentricular and biventricular repair: Rhodes-, Discriminant-, CHSS1- and
CHSS2-Score. In the underlying studies the usual type of biventricular repair was
either surgical or balloon valvuloplasty. The Ross–Konno operation changes the LVOT
substantially and so some of the scores’ parameters. The purpose of this study is
to examine if these scores are still applicable if a Ross–Konno procedure is used.
Methods: Between January 2010 and December 2021, 51 pts with critical LVOT obstruction and
borderline LV were treated at our center. In 37 pts a biventricular repair was initially
pursued and in 14 pts univentricular repair. A retrospective single-center investigation
was carried out to evaluate all four scores. As second part of our investigation the
scores were calculated with proposed postoperative dimensions, by replacing all LVOT
dimensions with the pulmonary root diameter.
Results: 31 pts (84%) of our Ross–Konno cohort maintained a successful BVR. Perioperative
mortality: 4 pts (10.8%). Conversion to UVR: 2 pts (5.4%). 11 pts (79%) in our Norwood
cohort maintained a successful UVR. Perioperative mortality: 3 pts (21%). There were
significant differences (p < 0.005) between the two cohorts: MV diameter, AV diameter, aortic root diameter,
ascending aorta diameter, heart LAX and LV length. The Rhodes score predicted a different
pathway in 27 of 42 successfully treated pts, the Discriminant score in 15 of 42 pts,
the CHSS-1 score in 26 of 42 pts and the CHSS-2 score in 24 of 42 pts.
Adaption with the pulmonary autograft dimensions leads to higher sensitivity, regarding
a BVR, in all scores but result in lower specificity (see table).
Score
|
Sens. (%)
|
Sens. Mod. (%)
|
Spec. (5)
|
Spec. Mod(%)
|
Rhodes
|
11.43
|
45.71
|
100
|
75
|
Discriminant
|
54.29
|
100
|
75
|
0
|
CHSS-1
|
43.75
|
75
|
62.86
|
40
|
CHSS-2
|
50
|
81.27
|
57.14
|
37.14
|
Conclusion: The validity of these scores, in Ross–Konno patients with critical aortic stenosis
and borderline left ventricle, is limited.
Calculating the scores with the proposed changes after Ross–Konno procedure may result
in a too large shift towards biventricular repair and an unacceptable loss of specificity.