A national study of the outcome after treatment of critical aortic stenosis in the neonate

Long-term outcome after neonatal intervention for congenital critical aortic stenosis

BACKGROUND

This study explored long-term outcome and functional status of patients born with critical aortic stenosis (CAS) following neonatal surgical or catheter interventions.

METHODS

A 40-year retrospective review of all consecutive patients within a large, single-center referral unit who required neonatal (<30 days) intervention for CAS. Additional detailed evaluation of surviving patients >7 years age was performed, with clinical assessment, objective cardiopulmonary exercise testing and state-of-the-art characterization of myocardial function (advanced echocardiography and cardiac MRI).

RESULTS

Between 1970 and 2010, ninety-six neonates underwent CAS intervention (mean age 9 ± 7.5 days). Early death occurred in 19 (19.8%) and late death in 10 patients. Overall survival at 10 and 30 years was 70.1% and 68.5%, freedom from reintervention was 41.8% and 32.9% respectively. Among the 25 long-term survivors available for detailed assessment (median age 15.7 ± 6.4 years), 55% exhibited impaired peak oxygen uptake. Mean left ventricle (LV) ejection fraction was 65 ± 11.2%, with a mean LV end-diastolic volume z-score of 0.02 ± 1.4. Mean LV outflow tract Vmax was 2.3 ± 1.02 m/s. CAS patients had reduced LV longitudinal and increased radial strain (p = 0.003, p < 0.001 respectively). Five patients had severe LV diastolic dysfunction associated with endocardial fibroelastosis (EFE) (p = 0.0014).

CONCLUSION

Despite high early mortality rate, long-term survival of patients with CAS is reasonable at the expense of high reintervention rate. With successful intervention, there remained long-term clinical and subclinical LV myocardial impairment, of which EFE was one marker. Long-term follow-up of all CAS patients is crucial, involving detailed myocardial functional assessment to help elucidate physiology and optimise management.

Balloon Valvuloplasty in Congenital Critical Aortic Valve Stenosis in Neonates and Infants: A Rescue Procedure for the Left Ventricle

Congenital critical aortic valve stenosis (CAVS) is a life-threatening disease requiring urgent treatment. First-line therapy is still controversial. The aim of our study was (1) to analyze retrospectively the patients of our institution who underwent balloon aortic valvuloplasty (BAV) due to CAVS and (2) describe the techniques for improved feasibility of intervention using microcatheters and retrieval loops. Twelve patients underwent 23 BAVs: 1 BAV was performed in 3 patients, 2 BAVs were performed in 7 patients, and 3 BAVs were performed in 2 patients. The peak trans-valvular pressure gradient (Δp) and left ventricular shortening fraction (LVSF) improved significantly in the first two interventions. In the first BAV, Δp decreased from 73.7 ± 34.5 mmHg to 39.8 ± 11.9 mmHg (p = 0.003), and the LVSF improved from 22.3 ± 13.5% to 31.6 ± 10.2% (p = 0.001). In the second BAV, Δp decreased from 73.2 ± 33.3 mmHg to 35.0 ± 20.2 mmHg (p < 0.001), and the LVSF increased from 26.7 ± 9.6% to 33.3 ± 7.4% (p = 0.004). Cardiac surgery during the neonatal period was avoided for all children. The median time to valve surgery was 5.75 years. Few complications occurred, namely mild-to-moderate aortic regurgitation, one remediable air embolism, and one intimal injury to the ascending aorta. We conclude that BAV is a successful emergency treatment for CAVS, resulting in left ventricular relief, clinical stabilization, and a time gain until cardiac surgery.

Outcomes in neonatal critical and non-critical aortic stenosis: a retrospective cohort study

OBJECTIVE

To compare long-term survival, reinterventions and risk factors using strict definitions of neonatal critical and non-critical valvular aortic stenosis (VAS).

DESIGN

A nationwide retrospective study using data from patient files, echocardiograms and the Swedish National Population Registry.

SETTING AND PATIENTS

All neonates in Sweden treated for isolated VAS 1994-2018. We applied the following criteria for critical aortic stenosis: valvular stenosis with duct-dependent systemic circulation or depressed left ventricular function (fractional shortening ≤27%). Indication for treatment of non-critical VAS was Doppler mean gradient >50 mm Hg.

MAIN OUTCOME MEASURES

Short-term and long-term survival, aortic valve reinterventions need of valve replacements, risk factors for reintervention and event-free survival.

RESULTS

We identified 65 patients with critical VAS and 42 with non-critical VAS. The majority of the neonates were managed by surgical valvotomy. Median follow-up time was 13.5 years, with no patients lost to follow-up. There was no 30-day mortality. Long-term transplant-free survival was 91% in the critical stenosis group and 98% in the non-critical stenosis group (p=0.134). Event-free survival was 40% versus 67% (p=0.002) in the respective groups. Median time from the initial treatment to reintervention was 3.6 months versus 3.9 years, respectively (p=0.008).

CONCLUSIONS

Critical VAS patients had significantly higher need for reintervention during the first year of life, lower event-free survival and lower freedom from aortic valve replacement at age ≥18 years, compared with neonates with non-critical stenosis.

Aortic Valve Repair in Neonates With Aortic Stenosis and Reduced Left Ventricular Function

This study assessed outcomes of neonatal aortic valve (AoV) repair in presumed high-risk patients with depressed left ventricular (LV) function. A retrospective analysis of all neonates who underwent isolated AoV repair for severe aortic stenosis (AS) was performed. Patients with moderate or severe LV dysfunction were compared to those with normal or mild LV dysfunction. From 1980-2021, 43 neonates underwent isolated AoV repair for AS. Of these, 16 patients (37.2%) had ≥moderate LV dysfunction. Mean LV ejection fraction (EF) was 32.8 ± 9.1%. Valve morphology was mostly unicuspid (68.75%, 11/16). Median age at surgery was 6.5 days (IQR 1-17.5). An optimal repair result with ≤mild AS or aortic regurgitation was achieved in 75% (12/16). There was no early death. One patient (6.25%) required postoperative extracorporeal membrane oxygenation (ECMO) support for 3 days. LVEF improved after surgery to 56.4 ± 12.6% before discharge (P < 0.0001) and normalized in 87.5% (14/16) with a median time of 6.4 days (IQR 3.4-39). Freedom from AoV reoperation was 45.1% (95%CI 17.9-69.3%) and 27.1% (95%CI 6.8-53%) at 5 and 10 years, respectively. Freedom from AoV replacement was 59% (95%CI 27-80.8%) and 31.4% (95%CI 6-62.2%) at 5 and 10 years, respectively. While survival was similar, freedom from AoV reoperation and replacement tended to be lower compared to neonates with preserved LVEF. AoV repair was associated with a low incidence of postoperative ECMO and mortality. LV function normalized after relief of obstruction in most patients before discharge. Late reoperation remained common for those with severely dysplastic valves.