Diagnostic Approach in Fetal Coarctation of the Aorta: A Cost-Utility Analysis.

BACKGROUND

Coarctation of the aorta (CoA) is difficult to diagnose by fetal echocardiogram (F-Echo), often requiring multiple F-Echos during gestation and neonatal echocardiograms (N-Echos) after birth. Furthermore, CoA is the most common ductal-dependent lesion missed on routine physical exam.

OBJECTIVES

We sought to determine the most cost-effective diagnostic approach in caring for infants in whom an initial F-Echo is concerning for CoA.

METHODS

Four paradigms for management after initial F-Echo could not rule out CoA were compared, with a single paradigm involving additional F-Echos: (1) multiple F-Echos for diagnostic clarity and performance of N-Echo on neonates with remaining high suspicion for CoA on F-Echos (prenatal-multiple), (2) no further F-Echo and performance of N-Echo on neonates with high suspicion for CoA on initial F-Echo (postnatal-selective), (3) no further F-Echo and performance of N-Echo on all neonates (postnatal-all), and (4) no further F-Echo or N-Echo with reliance on routine physical exam to identify afflicted infants (postnatal-none). Decision analysis models were constructed. Probabilities dictating clinical course and costs were calculated using our institution's study population. The utility-state values were derived from existing literature. The measure of effectiveness was quality-adjusted life years. To represent societal perspectives, cost was defined as hospital reimbursement payments.

RESULTS

From 2007 to 2014 at our institution, 92 patients were diagnosed with CoA and met the inclusion criteria for this study. These patients presented to care either through prenatal diagnosis (n = 31), postnatal examination findings while clinically well (n = 41), or after clinical deterioration in extremis (n = 20), with one patient subsequently dying. Presenting in extremis was associated with a 20% increase in the cost of their subsequent care and with a 51% increase in length of hospital stay. Postnatal-none was the least effective paradigm but also the least costly, thus forming the baseline model. Of the three other diagnostic approaches modeled, Postnatal-all was the cost-effective paradigm, maximizing utility due to avoidance of high-cost/low-utility disease states such as presentation in extremis and death. Prenatal-multiple was the next most effective but was also the most expensive.

CONCLUSIONS

Echocardiography is the screening gold standard in avoiding the devastating clinical manifestations of a missed CoA. When a diagnosis of CoA cannot be ruled out on initial F-Echo, the most cost-effective approach is performance of N-Echo on all neonates with no further prenatal evaluation.