Prognosis

The prognosis of a patent ductus arteriosus (PDA) depends largely on the size and magnitude of the shunt and the status of the pulmonary vasculature. Many patients with small ductus arteriosus never have signs of significant haemodynamic impairment and, other than the risk of endarteritis, have a normal prognosis. Those patients with significant left heart volume overload, however, are at risk of congestive heart failure or irreversible pulmonary vascular disease, even if asymptomatic or minimally symptomatic during childhood.[32]

Premature infants

Premature infants with a clinically significant persistent PDA are at risk of increased mortality compared with infants of a similar gestational age and birth weight without PDA.[96][97] One study found that those with a persistent significant PDA (despite attempted closure) had four times the risk of death compared to premature infants without a significant PDA.[98]​ These infants also suffer from increased morbidity related to the effects of increased pulmonary blood flow (pulmonary oedema, pulmonary haemorrhage, bronchopulmonary dysplasia [BPD], and pulmonary hypertension) and systemic undercirculation (hypotension, necrotising enterocolitis, intraventricular haemorrhage, and acute kidney injury) due to left-to-right shunting.[19][20]​​[21]​​[24]​​​[50]​​​[99][100][101][102]​​​​ The risk of mortality and morbidity appear to be similar regardless of whether the infant is managed expectantly or with early pharmacological therapy.[69][103][104][105]​​​ Emerging data suggest that the duration of exposure to a clinically significant PDA, rather than simply the presence or absence of a shunt, is the more important risk factor for development of BPD.[59]​ Infants who require surgical ligation generally have a worse outcome; this may be due to the fact that this is a more severely compromised patient population.[106][107][108][109]

Full-term infants and children

Prior to the era of antibiotics, surgery, and catheter closure, natural history studies demonstrated risk of death as 0.42% per year (aged 2 to 19 years), 1.0% per year (20 to 29 years), and 1.8% per year (30 to 39 years).[31] The estimated risk of endarteritis has been estimated at 0.45% per year for an untreated duct.[31] With current treatment strategies, mortality and endarteritis occur rarely.[110] Spontaneous closure of a patent ductus after 3 months of age is relatively rare. If a significant shunt is left untreated, it can result in the development of pulmonary obstructive disease that can become manifest as early as 15 months of life. A more moderate untreated shunt may not present with such symptoms until later in life. In patients with smaller ducts, the risk of morbidity is very low and is mainly related to the risk of endarteritis. Clinically silent PDAs appear to carry a relatively low risk for endarteritis with only a few case reports in the literature.[111][112] However, most patients, regardless of shunt size, are now referred for either catheter or surgical closure. Overall prognosis of these patients is very good after closure; typically patients are well and the procedure is considered curative. However, there are rare instances when increased pulmonary resistance may remain, even after closure of the duct. This is thought to be related to a primary abnormality of the pulmonary vasculature.[32]

Use of this content is subject to our disclaimer