PO-03-126 CONTEMPORARY OUTCOMES IN NEONATES WITH ISOLATED CONGENITAL COMPLETE HEART BLOCK– AN ANALYSIS OF THE PHIS DATABASE

Abstract

Congenital Complete Heart Block (CCHB) is a rare diagnosis, with limited multicenter outcomes data. Prior reports have observed pacemaker (PM) placement in 69% of fetal diagnosed patients by age 1 and in 74-96% of patients by age 20. Rates of PM placement and mortality in a contemporary CCHB cohort have not been well described. We performed a multicenter retrospective cohort study utilizing the Pediatric Health Information Systems (PHIS) database to analyze time to PM and in-hospital mortality in neonates with isolated CCHB. All subjects in the PHIS database (1/1/2007-12/31/2021) with ICD-9 or ICD-10 diagnosis code for congenital heart block or complete AV block and with age at index hospitalization < 30 days were included. Subjects with lower degree AV block, Long QT Syndrome, or structural congenital heart disease, except patent ductus arteriosus or atrial septal defect, were excluded. Cumulative incidence functions of time to PM were modeled with death as a competing risk. Cause-specific hazard regression analyses of PM placement were performed. There were 691 unique CCHB subjects identified from 47 US hospitals. The cohort was 58% female, 60% white, and 50% privately insured. Mean age at hospitalization was 0.8 days (SD 2.7). Median length of stay of index hospitalization was 11 days (IQR 5-28), and median follow-up duration was 1.7 years (IQR 0.1-6.4). PM placement occurred in 397 (57%) subjects, of whom 308 (45%) received PM in the index hospitalization. Median age at PM was 6 days (IQR 2-58), with 164 (41%) receiving single chamber and 224 (56%) dual chamber PM. In-hospital mortality occurred in 68 (9.8%) subjects. With death as a competing risk, predicted cumulative incidence of PM at 1 year is 50% (95% CI 47-54%). In multivariate analysis, gestational age (GA) 35-36 weeks had HR 1.4 of PM (95% CI 1.2-3.2, p=0.007) compared to term infants. GA ≤ 30 weeks and GA 31-34 weeks had increased hazard of mortality with HR 49 (95% CI 17-147, p<0.005) and 5.9 (95% CI 2-19, p=0.003), respectively. GA ≤ 30 weeks was associated with reduced hazard of PM with HR 0.5 (95% CI 1.4-3.6, p=0.005). In this largest published cohort of neonates with CCHB, predicted PM placement occurred in 50% by 1 year and in-hospital mortality rate was 9.8%. Severe and moderate prematurity are associated with increased mortality, which may explain the reduced risk of PM, whereas late preterm infants have increased risk of PM.Tabled 1Table 1: Characteristics of CCHB SubjectsCharacteristicsDescriptionAll (n=691)Permanent Pacemaker (n=397)No Pacemaker (n=237)Death Without Pacemaker Placement (n=57)P-valueSexMale294 (43%)158 (40%)108 (46%)28 (49%)0.21Female397 (58%)239 (60%)129 (54%)29 (51%)RaceBlack105 (15%)55 (14%)34 (14%)16 (28%)<0.0001White417 (60%)256 (65%)140 (59%)21 (37%)Other125 (18%)67 (17%)49 (21%)9 (16%)Missing44 (6%)19 (5%)14 (6%)11 (19%)Census RegionMidwest217 (31%)131 (33%)73 (31%)13 (23%)0.055Northeast118 (17%)58 (15%)48 (20%)12 (21%)South230 (33%)125 (32%)79 (33%)26 (46%)West126 (18%)83 (21%)37 (16%)6 (11%)Age in days at index hospitalization, mean (SD)0.8 (2.7)0.5 (2.1)0.9 (3.0)2.0 (4.7)0.0008Gestational age, n (%)<= 30 weeks76 (11%)23 (6%)22 (9%)31 (54%)<0.000131-34 weeks115 (17%)76 (19%)32 (14%)7 (12%)35-36 weeks143 (21%)100 (25%)37 (16%)6 (11%)>= 37 weeks269 (39%)146 (37%)117 (49%)6 (11%)Missing88 (13%)52 (13%)29 (12%)7 (12%)Birth weight in grams, mean (SD)2509 (823)2547 (703)2650 (830)1650 (1033)0.949Hydrops Fetalis, n (%)36 (5%)19 (5%)7 (3%)10 (18%)<0.0001Steroid use in index hospitalization, n (%)212 (31%)137 (35%)40 (17%)35 (61%)<0.0001Isoproterenol use in index hospitalization, n (%)269 (39%)197 (50%)41 (17%)31 (54%)<0.0001Length of stay, index hospitalization, median (IQR)11 (5, 28)14 (8, 32)8 (4, 19)5 (1, 16)Mortality in index hospitalization, n (%)68 (9.8%)11 (3%)0 (0%)57 (100%) Open table in a new tab