Maternal and neonatal outcomes in women with history of coronary artery disease.

BACKGROUND: Pregnancy outcomes in women with pre-existing coronary artery disease (CAD) are poorly described. There is a paucity of data therefore on which to base clinical management to counsel women, with regard to both maternal and neonatal outcomes. METHOD: We conducted a retrospective multicentre study of women with established CAD delivering at 16 UK specialised cardiac obstetric clinics. We included pregnancies of 24 weeks' gestation or more, delivered between January 1998 and October 2018. Data were collected on maternal cardiovascular, obstetric and neonatal events. RESULTS: 79 women who had 92 pregnancies (94 babies including two sets of twins) were identified. 35.9% had body mass index >30% and 24.3% were current smokers. 18/79 (22.8%) had prior diabetes, 27/79 (34.2%) had dyslipidaemia and 21/79 (26.2%) had hypertension. The underlying CAD was due to atherosclerosis in 52/79 (65.8%), spontaneous coronary artery dissection (SCAD) in 11/79 (13.9%), coronary artery spasm in 7/79 (8.9%) and thrombus in 9/79 (11.4%).There were six adverse cardiac events (6.6% event rate), one non-ST elevation myocardial infarction at 23 weeks' gestation, two SCAD recurrences (one at 26 weeks' gestation and one at 9 weeks' postpartum), one symptomatic deterioration in left ventricular function and two women with worsening angina. 14% of women developed pre-eclampsia, 25% delivered preterm and 25% of infants were born small for gestational age. CONCLUSION: Women with established CAD have relatively low rates of adverse cardiac events in pregnancy. Rates of adverse obstetric and neonatal events are greater, highlighting the importance of multidisciplinary care.

Birth weight in pregnancies complicated by maternal heart disease.

OBJECTIVE: To assess median and percentile birthweight distribution in women with various groups of heart disease relative to a contemporaneous comparison group. METHODS: Data on birth weight and gestational age were collected from 1321 pregnancies ≥24 weeks' gestation in 1053 women with heart disease from seven UK maternity units. Women were assigned to one of 16 groups according to their cardiac lesion. In units where it was possible, data on two births, one delivering before and one after index cases, were collected, giving 2307 comparators. Birthweight percentiles (corrected for gestational age, sex and parity) were calculated using Aberdeen norms. We assessed the association of birth weight with cardiac lesion, maternal hypoxaemia (saturations <90%), systemic ventricular function and beta-blockers. RESULTS: 1321 pregnancies in women with heart disease and 2307 comparators were studied. Almost all groups with heart disease had lower median and percentile birth weights than comparators, significantly in 10 groups, the biggest effect seen in women with Fontan circulation, pulmonary hypertension, prosthetic heart valves, systemic right ventricle, Marfan syndrome, repaired tetralogy of Fallot and cardiomyopathy (in that order). In 307 pregnancies, women took beta-blockers; median birth weight adjusted for maternal age, parity and the effect of the cardiac lesion was 3116.7 g (IQR 790.4) when beta-blockers were used and 3354.3 g (IQR 634.1) when they were not (p<0.001). 17 women had saturations <90%, and median birth weight was significantly lower, 3105.4 g (IQR 1288.9) versus 3387.7 g (IQR 729.8) (p=0.006). CONCLUSION: Our findings identify specific groups of women with heart disease at risk of having a small baby.

Retrospective UK multicentre study of the pregnancy outcomes of women with a Fontan repair.

BACKGROUND: The population of women of childbearing age palliated with a Fontan repair is increasing. The aim of this study was to describe the progress of pregnancy and its outcome in a cohort of patients with a Fontan circulation in the UK. METHODS: A retrospective study of women with a Fontan circulation delivering between January 2005 and November 2016 in 10 specialist adult congenital heart disease centres in the UK. RESULTS: 50 women had 124 pregnancies, resulting in 68 (54.8%) miscarriages, 2 terminations of pregnancy, 1 intrauterine death (at 30 weeks), 53 (42.7%) live births and 4 neonatal deaths. Cardiac complications in pregnancies with a live birth included heart failure (n=7, 13.5%), arrhythmia (n=6, 11.3%) and pulmonary embolism (n=1, 1.9%). Very low baseline maternal oxygen saturations at first obstetric review were associated with miscarriage. All eight women with saturations of less than 85% miscarried, compared with 60 of 116 (51.7%) who had baseline saturations of ≥85% (p=0.008). Obstetric and neonatal complications were common: preterm delivery (n=39, 72.2%), small for gestational age (<10th percentile, n=30, 55.6%; <5th centile, n=19, 35.2%) and postpartum haemorrhage (n=23, 42.6%). There were no maternal deaths in the study period. CONCLUSION: Women with a Fontan circulation have a high rate of miscarriage and, even if pregnancy progresses to a viable gestational age, a high rate of obstetric and neonatal complications.

Slowed conduction and ventricular tachycardia after targeted disruption of the cardiac sodium channel gene Scn5a.

Voltage-gated sodium channels drive the initial depolarization phase of the cardiac action potential and therefore critically determine conduction of excitation through the heart. In patients, deletions or loss-of-function mutations of the cardiac sodium channel gene, SCN5A, have been associated with a wide range of arrhythmias including bradycardia (heart rate slowing), atrioventricular conduction delay, and ventricular fibrillation. The pathophysiological basis of these clinical conditions is unresolved. Here we show that disruption of the mouse cardiac sodium channel gene, Scn5a, causes intrauterine lethality in homozygotes with severe defects in ventricular morphogenesis whereas heterozygotes show normal survival. Whole-cell patch clamp analyses of isolated ventricular myocytes from adult Scn5a(+/-) mice demonstrate a approximately 50% reduction in sodium conductance. Scn5a(+/-) hearts have several defects including impaired atrioventricular conduction, delayed intramyocardial conduction, increased ventricular refractoriness, and ventricular tachycardia with characteristics of reentrant excitation. These findings reconcile reduced activity of the cardiac sodium channel leading to slowed conduction with several apparently diverse clinical phenotypes, providing a model for the detailed analysis of the pathophysiology of arrhythmias.