Assistant professor Texas Children's Hospital Houston, Texas, United States
Abstract: Introduction/
Objective: An elevated B-type natriuretic peptide (BNP) has been associated with increased mortality and complications in patients with congenital heart disease. We describe the preoperative, perioperative, and postoperative BNP trends in patients with HLHS from S1P until interstage discharge to home or stage 2 surgical palliation (S2P).
Methods: This is a prospective cohort study including all newborns with hypoplastic left heart syndrome (HLHS) who underwent Norwood procedures (S1P) at Texas Children’s Hospital from April 2018 through April 2019. BNP levels were assessed in all patients at four time periods: preoperative S1P (phase I), ICU admission after S1P to first extubation (phase II), first extubation to acute care transfer (phase III), and to acute care transfer to any of the study endpoints: interstage discharge home, death, S2P (phase IV).
Results: Our study included 19 newborns with HLHS; 53% were male with a median weight of 3.1 kg [IQR 2.7-3.5 kg] and gestational age of 39 weeks (range 35-40 weeks). The preoperative BNP median was 3,385 pg/mL [IQR 2,480-5,374 pg/mL]. All patients survived to hospital discharge (47%) or S2P (53%). Nine patients (50%) had higher BNP levels immediately after arrival to the cardiac intensive care unit (ICU) after S1P compared to preoperative levels, Figure 1. BNP levels were higher (p=0.02) in patients with moderately depressed right ventricular systolic function in the immediate postoperative period (median of 6,821 pg/mL) compared to those with normal or mildly depressed function (median of 3,259 pg/mL). Once discharged from ICU, BNP levels trended higher (p=0.05) in those patients with cardiac complications (median 221 pg/mL vs. 139 pg/mL). Twelve patients (63%) underwent modified Blalock Taussig Thomas shunt (mBTTs) and seven (37%) right ventricular to pulmonary artery shunt (RVPAs). RVPAs patients (p=0.02) had higher BNP levels (median 3,357 pg/mL) than mBTTs (median 2,756 pg/mL) on admission to intensive care unit (ICU) after S1P and following extubation (RVPAs median 784 pg/mL vs. mBTTs median 614 pg/mL), p=0.009, Figure 2. Despite higher BNP levels in RVPAs, these subjects had shorter mechanical ventilation, ICU, and hospital length of stay duration.
Conclusions: BNP trends for HLHS patients vary in the postoperative period after S1P in mBBTs and RVPAs patients. RVPAs had higher BNP levels than mBTTs in the early postoperative period after S1P; however, this was not associated with worse outcomes.
