Pulmonary Artery Hypertension with Patent Ductus Arteriosus: Understanding the Chances of Spontaneous Closure

Patent Ductus Arteriosus (PDA) is one of the most common types of congenital heart defects in infants, accounting for approximately 10% of all congenital heart disease cases. During fetal development, the ductus arteriosus remains open to support fetal circulation. Normally, this duct begins to close functionally within the first 15 hours after birth, with around 80% of infants experiencing full anatomical closure within three months. By the age of one year, the ductus arteriosus should be completely closed in a normal developmental process.

What Happens When the Ductus Arteriosus Remains Open?

If the duct remains open beyond the first year of life, it is classified as a patent ductus arteriosus. In most cases, isolated PDA without complications may have a small chance of spontaneous closure in early infancy, but this probability drops significantly after the age of one. At this stage, natural closure is highly unlikely without medical intervention.

The Complication of Pulmonary Artery Hypertension

When PDA is accompanied by pulmonary artery hypertension, the likelihood of spontaneous resolution becomes virtually zero. A large PDA allows excessive blood flow from the left side of the heart to the right, increasing pulmonary blood flow and vascular resistance. This leads to elevated pulmonary artery pressure, resulting in what is known as dynamic pulmonary hypertension.

Progression to Obstructive Pulmonary Hypertension

As the condition progresses, the increased pressure and resistance in the pulmonary vasculature can cause irreversible structural changes. This transition marks the development of obstructive pulmonary hypertension, a serious complication that prevents the ductus from closing naturally and may lead to right heart failure if left untreated.

Why Medical Intervention Is Necessary

Given the hemodynamic changes associated with PDA and pulmonary hypertension, timely diagnosis and treatment are essential. Options may include pharmacologic therapy in premature infants or interventional procedures such as catheter-based closure or surgical ligation in more advanced cases. Without treatment, the risk of long-term complications—including heart failure, arrhythmias, and endocarditis—significantly increases.