(32) Adverse Cardiovascular Consequences of Conservative Treatment in Infants with a Hemodynamically Significant Patent Ductus Arteriosus

Background: Traditionally, extremely preterm infants (EPIs; < 28 weeks’ gestation) with a hemodynamically significant patent ductus arteriosus (HSPDA) underwent definitive treatment (surgical ligation, percutaneous closure). Given known risks of definitive closure, many health care providers have adopted conservative PDA management strategies (non-intervention) without data on the short and longer-term consequences of this approach.

Objectives: Among EPIs with HSPDA, to characterize associated risk factors for the development of severe cardiovascular compromise (defined below) after initial attempts at conservative management.

Design/Methods: Contemporary (1/2010-12/2019), retrospective review at a large, pediatric referral center among EPIs with HSPDA > postnatal day 21 (beyond window when drug therapy is most efficacious). HSPDA was defined as moderate/large ductus (minimum diameter) with left-sided atrial/ventricular chamber enlargement and mechanical ventilation. A consensus-based definition of severe cardiovascular compromise included: left-sided cardiac (atrium, ventricle) enlargement (Z-score >4) with damage to the mitral valve apparatus (e.g., mitral regurgitation) clearly/likely attributable to HSPDA exposure (absence of other etiologies). Data extraction and assignment of attributability and severity of HSPDA exposure were independently performed by multiple observers.

Results: Among 180 EPIs with HSPDA, 803 ECHOs were independently reviewed, of which we identified 52 infants (29%) with severe cardiovascular compromise. Interrater agreement on evidence of severe cardiovascular compromise, and the attributability of the HSPDA to severe cardiovascular compromise, were high (κ = 0.95, 0.92, respectively). EPIs with severe cardiovascular compromise were born more premature (24.2 vs. 26.1 weeks of gestation; P=0.02) and had longer median exposure to HSPDA (146 vs. 62 days; P< 0.01) than EPIs without severe cardiovascular compromise. Of the severe cardiovascular compromised group, there were 34 infants (65%) who failed conservative treatment and underwent procedural closure (7 surgical ligations, 27 percutaneous); the remaining 18 (35%) infants had spontaneous ductal closure or no longer had HSPDA at initial hospital discharge.

Conclusion: Optimal management strategies for EPI with an HSPDA remain unanswered, reinforcing the critical need for well-designed, pragmatic clinical trials in this high-risk subgroup.