Dichotomy in biventricular function, progress and recovery among extreme preterm infants with persistent ductus arteriosus.

OBJECTIVE

To evaluate the biventricular functional changes in persistent patent ductus arteriosus (PDA) in extreme premature population.

DESIGN

Prospective observational study.

SETTING

Single-center, tertiary-level neonatal intensive care unit.

PATIENTS: Infants born <28 weeks gestation.

MAIN OUTCOME MEASURES: Serial cardiac function was evaluated using tissue Doppler echocardiography in 80 preterm infants born <28 weeks of gestation. Recruited infants had 4 weekly scans till 36 weeks. The serial cardiac function was compared between infants with persistent PDA beyond the first week of life and those with closed PDA.

RESULTS

Eighty infants were recruited. The incidence of moderate to severe BPD (51vs. 7, p = 0.01, OR 4.2, 95% CI 1.2-14.4), BPD-PH (28 vs. 3, p = 0.01, OR 5.07 95% CI 1.7-14.5) was higher among persistent PDA groups. The tissue Doppler imaging among persistent PDA cohort showed prolonged right ventricular (RV) isovolumetric relaxation time (IVRT) (38.9 ± 8.6 vs. 36.2 ± 7.8, p = 0.02) and RV myocardial performance index (MPI) (0.37 ± 0.06 vs. 0.35 ± 0.05, p = 0.04). The persistent PDA group had a higher left ventricular (LV) E/E' ratio (12.2 ± 4.7 vs. 8.9 ± 2, p = 0.01). The serial scans showed an abnormal left ventricular eccentricity index (1.07 ± 0.1 vs. 0.96 ± 0.2, p = 0.03), prolonged RV IVRT (39.8 ± 11 vs. 32.7 ± 6.5, p < 0.001), and RV MPI (0.36 ± 0.1 vs. 0.31 ± 0.04, p < 0.05) up to 36 weeks. The LV E/E' and LV E'/A' were abnormal for up to 33 weeks and normalized by 36 weeks of gestation.

CONCLUSION

A significant dichotomy exists between biventricular function, progression, and recovery in PDA-exposed extreme premature neonates. The RV dysfunction was consistent and persisted longer than LV changes.