187 - Abnormal Cardiovascular Status Is Associated with Intracranial Pathology and Low Middle Cerebral Artery Flow Among Preterm Infants.

Poster Number: 187
Publication Number: 187.219

Mohamed Al Kanjo, University of Iowa Stead Family Children's Hospital, Iowa City, IA, United States; Danielle R. Rios, University of Iowa Stead Family Children's Hospital, Iowa City, IA, United States; Stephanie S. Lee, University of Iowa Stead Family Children's Hospital, Iowa City, IA, United States; Patrick J. McNamara, University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, IA, United States; Regan E. Giesinger, University of Iowa, Iowa City, IA, United States

Background: In preterm infants, fluctuating cerebral blood flow (CBF) is implicated in many central nervous system pathologies (CNSP) [e.g., hemorrhage, asphyxia], however, studies on the role of CBF Doppler indices in evaluating cerebrovascular disease in preterm infants are limited. Middle cerebral artery (MCA) Doppler may be a useful adjunct to conventional clinical and echocardiography measures of CNSP risk factors.

Objective: To evaluate whether CNSP is associated with cardiovascular compromise in the context of MCA hemodynamics in preterm infants [ < 32 weeks gestational age (GA)].

Design/Methods: A retrospective cohort study of all patients’ first Targeted Neonatal Echocardiograms (TnECHOs) [1/1/20-7/31/20] was conducted. Patients were stratified as cases [hypotensive or receiving cardiovascular (CV) therapy] vs controls [normotensive without treatment] at the time of TnECHO. Hypotension was defined as mean blood pressure < GA in weeks. A single trained operator, blinded to clinical status, performed offline measurements of MCA Doppler-derived blood flow velocities [Peak systolic; end systolic; and end diastolic], and calculation of MCA indices [resistive (RI) and pulsatility (PI)]. The primary outcome was the composite of death/CNSP, and secondary outcomes were MCA Doppler-derived flow variables. Univariate analysis of demographics and binary logistic regression was performed.

Results: Of 63 eligible neonates, 31 (49%) cases and 32 (51%) controls were identified [Table 1]. Cases were younger and smaller at birth, had greater illness severity and had a higher burden of death/CNSP and CNSP alone.  All MCA flow velocities were lower in the cases but no difference in the MCA RI or PI between groups was identified [Table 2]. Logistic regression, to adjust the composite outcome for GA and treatment group, demonstrated peak systolic flow velocity as an independent predictor of death/CNSP [Table 3]. A diagnosis of hypotension and/or receipt of CV treatment demonstrated trends toward predictive odds ratios for the composite outcome across models.Conclusion(s): Among preterm patients who are hypotensive or receiving CV therapy, the use of peak systolic velocity of the MCA may be an additional prognostic tool to indicate the need to screen for CNSP which is independent of GA. Further evaluation into the utility of MCA Doppler in this vulnerable cohort is warranted.
Resume 2022.pdf
Table 2: Central Nervous System Pathologies, Death, and Middle Cerebral Artery (MCA) variables by group: cases (hypotensive/treated) vs controls (untreated normotensive patients).