What is the incidence of Tetralogy of Fallot (TOF) with pulmonary atresia?

From the Guidelines

Tetralogy of Fallot with pulmonary atresia (TOF-PA) has an estimated incidence of approximately 0.07 per 1,000 live births, representing about 20% of all Tetralogy of Fallot cases, although the provided evidence does not directly state this incidence, it can be inferred from the prevalence of TOF and the proportion of TOF cases with pulmonary atresia. The provided evidence 1 discusses the prevalence and incidence of Tetralogy of Fallot (TOF), which is the most common cyanotic congenital heart disease, with a prevalence of ~6% of all congenital heart diseases and an average incidence of 32.6 per 100,000 live births. However, it does not specifically mention the incidence of TOF with pulmonary atresia. Some key points to consider when evaluating the incidence of TOF-PA include:

• The main pathologic basis of TOF is antero-cephalad deviation of the developing conal septum, which causes a malalignment type ventricular septal defect (VSD), resulting in an “overriding aorta” and right ventricular (RV) outflow tract (RVOT) obstruction, ultimately leading to RV hypertrophy, as described in the evidence 1.
• Repair typically consists of VSD closure and relief of RVOT obstruction, which may involve placement of a transannular patch or an RV to pulmonary artery conduit, both of which can result in pulmonary regurgitation (PR) and RV volume overload, as noted in the evidence 1.
• Definitive repair is generally performed in infancy with high survival rates, and the 30-year survival rate is >90%, as reported in the evidence 1. Given the lack of direct information on the incidence of TOF-PA in the provided evidence, the estimated incidence of approximately 0.07 per 1,000 live births, representing about 20% of all Tetralogy of Fallot cases, is based on general knowledge and should be considered in the context of clinical practice.

From the Research

Incidence of Tetralogy of Fallot with Pulmonary Atresia

• The incidence of Tetralogy of Fallot (TOF) with pulmonary atresia is not explicitly stated in the provided studies 2, 3, 4, 5, 6.
• However, it is described as a rare diagnosis with a heterogeneous group of complex anatomical findings 2.
• The studies focus on the management and treatment of TOF with pulmonary atresia, rather than providing epidemiological data on its incidence 3, 4, 5.

Characteristics of TOF with Pulmonary Atresia

• TOF with pulmonary atresia is characterized by complete failure of forward flow from the right ventricle to the pulmonary arterial system 2.
• Pulmonary blood flow is entirely dependent on shunting from the systemic circulation, most frequently via a patent ductus arteriosus, major aortopulmonary collaterals, or a combination of the two 2.
• The pathophysiology of TOF-PA is largely attributable to the abnormalities of the pulmonary vasculature 2.

Management and Treatment

• Patients with TOF-PA require operative intervention to create a reliable, controlled source of pulmonary blood flow and ideally complete intracardiac repair 2.
• An individualized approach to treatment, using unifocalization and aggressive attempts to recruit the available native pulmonary vasculature, can achieve outcomes in the intermediate term superior to the natural history of the lesions 3, 4.
• The goal of management is to establish pulmonary blood flow from the right ventricle with RV pressures that are ideally less than half of the systemic pressure to allow for closure of the ventricular septal defect 5.