Echocardiographic versus angiographic measurement of the aortic valve annulus in children undergoing balloon aortic valvuloplasty: method affects outcomes.

OBJECTIVE: Operators are mindful of the balloon-to-aortic annulus ratio when performing balloon aortic valvuloplasty. The method of measurement of the aortic valve annulus has not been standardised. METHODS AND RESULTS: Patients who underwent aortic valvuloplasty at two paediatric centres between 2007 and 2014 were included. The valve annulus measured by echocardiography and angiography was used to calculate the balloon-to-aortic annulus ratio and measurements were compared. The primary endpoint was an increase in aortic insufficiency by ≥2 degrees. Ninety-eight patients with a median age at valvuloplasty of 2.1 months (Interquartile range (IQR): 0.2-105.5) were included. The angiographic-based annulus was 8.2 mm (IQR: 6.8-16.0), which was greater than echocardiogram-based annulus of 7.5 mm (IQR: 6.1-14.8) (p < 0.001). This corresponded to a significantly lower angiographic balloon-to-aortic annulus ratio of 0.9 (IQR: 0.9-1.0), compared to an echocardiographic ratio of 1.1 (IQR: 1.0-1.1) (p < 0.001). The degree of discrepancy in measured diameter increased with smaller valve diameters (p = 0.041) and in neonates (p = 0.044). There was significant disagreement between angiographic and echocardiographic balloon-to-aortic annulus ratio measures regarding "High" ratio of >1.2, with angiographic ratio flagging only 2/12 (16.7%) of patients flagged by echocardiographic ratio as "High" (p = 0.012). Patients who had an increase in the degree of aortic insufficiency post valvuloplasty, only 3 (5.5%) had angiographic ratio > 1.1, while 21 (38%) had echocardiographic ratio >1.1 (p < 0.001). Patients with resultant ≥ moderate insufficiency more often had an echocardiographic ratio of >1.1 than angiographic ratio of >1.1 There was no association between increase in balloon-to-aortic annulus ratio and gradient reduction. CONCLUSIONS: Angiographic measurement is associated with a greater measured aortic valve annulus and the development of aortic insufficiency. Operators should use caution when relying solely on angiographic measurement when performing balloon aortic valvuloplasty.

Premounted stents for branch pulmonary artery stenosis in children: A short term solution.

OBJECTIVE: Define outcomes of premounted stent implantation (PMS) for branch pulmonary artery stenosis (BPAS). BACKGROUND: PMS for BPAS in children raises concern of long term viability, with limited maximal expansion. METHODS: We reviewed our cardiac database over an 11-year period ending in 2013. Primary endpoint was need for surgical stent intervention (SSI). Other endpoints included acute results and repeat interventions (RI). RESULTS: 82 PMS were implanted in 60 children for BPAS. Median weight was 6.3 (25th -75th 4.6-9.8) kg. Median stent diameter was 6 (range 4-9) mm. Acutely, vessel diameter improved from 2.0 (25th -75th 1.6-3.4) to 5.0 (25th -75th 4.2-5.9) mm (p < 0.001), pressure gradient decreased from 41 (25th -75th 29-50) to 11 (25th -75th 7-18) mmHg (n = 47, p < 0.001), RV:Ao pressure ratio decreased from 100% (25th -75th 85-110%) to 59% (25th -75th 49-74%) (n = 40, p < 0.001). Freedom from SSI was 81% at 1 year and 35% at 5 years. Freedom from RI was 50% at 1 year and 14% at 5 years. 86% of PMS underwent SSI during a concomitant planned cardiac surgery. 45% patients had stent redilation, improving stent diameter from 4.6 (25th -75th 4.1-5.4) to 5.7 (25th -75th 4.9-7) mm (p < 0.001). 1 stent (3%) was able to be fractured longitudinally. CONCLUSIONS: PMS is an effective short term solution for BPAS in children. PMS is associated with expected early need for transcatheter reintervention to accommodate for growth, but also has high rates of SSI.

Relation of Aortic Valve Morphologic Characteristics to Aortic Valve Insufficiency and Residual Stenosis in Children With Congenital Aortic Stenosis Undergoing Balloon Valvuloplasty.

Aortic valve morphology has been invoked as intrinsic to outcomes of balloon aortic valvuloplasty (BAV) for congenital aortic valve stenosis. We sought to use aortic valve morphologic features to discriminate between valves that respond favorably or unfavorably to BAV, using aortic insufficiency (AI) as the primary outcome. All patients who underwent BAV at 2 large-volume pediatric centers from 2007 to 2014 were reviewed. Morphologic features assessed on pre-BAV echo included valve pattern (unicuspid, functional bicuspid, and true bicuspid), leaflet fusion length, leaflet excursion angle, and aortic valve opening area and on post-BAV echo included leaflet versus commissural tear. Primary end point was increase in AI (AI+) of ≥2°. Eighty-nine patients (median age 0.2 years) were included in the study (39 unicuspid, 41 functional bicuspid, and 9 true bicuspid valves). Unicuspid valves had a lower opening area (p <0.01) and greater fusion length (p = 0.01) compared with functional and true bicuspid valves. Valve gradient pre-BAV and post-BAV were not different among valve patterns. Of the 16 patients (18%) with AI+, 14 had leaflet tears (odds ratio 13.9, 3.8 to 50). True bicuspid valves had the highest rate (33%) of AI+. On multivariate analysis, leaflet tears were associated with AI+, with larger opening area pre-BAV and lower fusion length pre-BAV. AI+ was associated with larger pre-BAV opening area. Gradient relief was associated with reduced angle of excursion. Valve morphology influences outcomes after BAV. Valves with lesser fusion and larger valve openings have higher rates of leaflet tears which in turn are associated with AI.