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.