Auld BC, Donald JS, Lwin N, Betts K, Alphonso NO, Venugopal PS, Justo RN, Ward CJ, Konstantinov IE, Karl TR, Anderson BW. Cardiol Young. 2021 Dec;31(12):1984-1990. doi: 10.1017/S1047951121001281. Epub 2021 Apr 16. PMID: 33858544
Take Home Points:
- Balloon aortic valvuloplasty and surgical aortic valvotomy both achieve acute relief of aortic stenosis with aortic regurgitation being more common in the balloon valvuloplasty group.
- Freedom from reintervention is similar between groups.
- Balloon aortic valvuloplasty has a much better freedom from reintervention in the neonatal population in a propensity matched comparison.
Commentary from Dr. Ryan Romans (Kansas City, MO), section editor of Congenital Heart Disease Interventions Journal Watch:
Congenital aortic stenosis (AS) continues to have significant morbidity and mortality despite improvements in transcatheter balloon aortic valvuloplasty (BAV-including lower profile balloons, two balloon technique, methods to achieve balloon stability) and surgical aortic valvotomy (SAV-including use of commissurotomy, leaflet edge thinning, debulking of nodular dysplasia, leaflet extension) over the last several decades. There continues to be significant debate surrounding which strategy should be first line therapy with the type of intervention typically dictated by center preference. Given this, a randomized controlled trial is challenging as the large majority undergo surgical repair or balloon valvuloplasty at any given center. This study performed a retrospective propensity score matched analysis from a primary surgical center and primary transcatheter center (both in Australia) to evaluate outcomes of BAV versus SAV in the treatment of AS.
From 2005-2016 65 patients (median age 92 days, IQR 21-924) underwent BAV and 77 patients (median age 167 days, IQR 38-2873) underwent SAV and met inclusion criteria (no other significant congenital heart disease that would impact the decision of what procedure would be performed). There were no significant differences in aortic valve morphology, age (p value 0.08, trend towards younger in BAV group), weight, or pre-procedure mean AS gradient by echocardiogram between groups. In the BAV group a balloon size similar to the annulus was chosen with two balloon technique utilized in patients with a larger annulus (12-13 mm) and balloon stabilization techniques (rapid RV pacing or administration of adenosine) when possible. The surgical technique utilized was determined by the surgeon intraoperatively.
SAV achieve a mean residual gradient by echocardiogram of 14.9 mmHg (IQR 10.7-21.4) while the gradient following BAV was 25.5 mmHg (IQR 16-31.5). There was no difference in mortality between groups. Moderate or greater aortic regurgitation was more common in the BAV group (15 patients) than the SAV group (1 patient). Three patients had severe aortic regurgitation post BAV and ultimately underwent an early Ross procedure as did the one SAV patient with moderate aortic regurgitation. Freedom from reintervention was similar between groups at 2 (75% for BAV, 74% for SAV), 4 (71% for BAV, 73% for SAV), and 8 years (62% for BAV, 63% for SAV). There was no association between initial type of intervention and need for reintervention. A total of 96 patients (48 from each group) were matched for propensity scoring with good balance achieved. In this matched sample, freedom from valve replacement was 78% for BAV and 81% in the surgical group. There was a trend (p-value 0.068) towards lower need for reintervention in the neonatal groups at 2 (72% for BAV, 40% for SAV), 4 (72% for BAV, 40% for SAV), and 8 years (72% for BAV, 32% for SAV).
This study reports on the results of BAV versus SAV in a modern cohort with further analysis using a propensity matched comparison. In general, both methods achieve relief of aortic stenosis (while SAV achieved a statistically lower residual gradient, a 10 mmHg lower gradient is unlikely to be clinically significant) with a much higher rate of aortic regurgitation in the BAV group. Despite this, BAV and SAV valvuloplasty had similar short- and medium-term reintervention rates. The propensity matched comparison showed that BAV resulted in much more durable results in the neonatal population. This argues that BAV should be considered first line in this higher risk patient population at all centers to delay need for surgical intervention. A recent meta-analysis (Moroi, M., Bacha, E., & Kalfa, D. (2021). The Ross procedure in children: a systematic review. Annals of Cardiothoracic Surgery, 10(4), 420-432. Doi:10.21037/acs-2020-rp-23) showed that mortality rates were higher in the neonatal and infant population. Given these findings, achieving optimal outcomes in this patient population is essential. When thinking about these outcomes it is important to remember that each center used its own reintervention criteria. This could lead to some patients undergoing reintervention at one center while they would not have at the other. Additionally, due to the determination for BAV versus SAV being a center-wide decision each center had experience and expertise in their chosen method which likely favorably impacted outcomes. Lastly, in my practice, I typically start with a balloon that is 80-90% of the annulus size for initial valvuloplasty rather than similar to the annulus size as the authors report. If there is still a significant gradient a larger balloon is chosen as long as there is not already significant aortic regurgitation. This slightly more conservative approach is taken to decrease the risk aortic regurgitation while hopefully still alleviating aortic stenosis.