Ursodeoxycholic acid prevents ventricular conduction slowing and arrhythmia by restoring T-type calcium current in fetuses during cholestasis

Intrahepatic cholestasis of pregnancy and fetal cardiac dysfunction: a systematic review and meta-analysis

OBJECTIVE

Intrahepatic cholestasis of pregnancy is associated with adverse perinatal outcomes. Fetal cardiac dysfunction may be 1 part of the pathophysiology of pregnancies complicated by intrahepatic cholestasis of pregnancy. This systematic review and meta-analysis aimed to evaluate the association between intrahepatic cholestasis of pregnancy and fetal cardiac dysfunction.

DATA SOURCES

Systematic searches were performed on the databases of Medline, Embase, and Cochrane Library (up to March 2, 2023) for studies evaluating fetal cardiac function in pregnancies complicated by intrahepatic cholestasis of pregnancy in addition to the reference lists of included studies.

STUDY ELIGIBILITY CRITERIA

Studies were eligible for inclusion if they assessed the fetal cardiac function by fetal echocardiography in women with intrahepatic cholestasis of pregnancy (mild or severe) and compared with fetuses of healthy pregnant women. The studies published in English were included.

METHODS

The quality of the retrieved studies was assessed using the Newcastle-Ottawa Scale. Data on fetal myocardial performance index, E wave/A wave peak velocities ratio, and PR interval were pooled for the meta-analysis using random-effects models. The results were presented as weighted mean differences and 95% confidence intervals. This meta-analysis was registered with the International Prospective Register of Systematic Reviews (registration number: CRD42022334801).

RESULTS

A total of 14 studies were included in this qualitative analysis. Of note, 10 studies that reported data on fetal myocardial performance index, E wave/A wave peak velocities ratio, and PR interval were included in the quantitative analysis and showed a significant association between intrahepatic cholestasis of pregnancy and fetal cardiac dysfunction. Significantly higher fetal left ventricular myocardial performance index values (weighted mean difference, 0.10; 95% confidence interval, 0.04-0.16) and longer fetal PR intervals (weighted mean difference, 10.10 ms; 95% confidence interval, 7.34-12.86) were revealed in pregnancies complicated by intrahepatic cholestasis of pregnancy. Compared with the situation in pregnancies complicated by mild intrahepatic cholestasis of pregnancy, PR intervals were even longer in pregnancies complicated by severe intrahepatic cholestasis of pregnancy (weighted mean difference, 5.98 ms; 95% confidence interval, 0.20-11.77). There was no significant difference in fetal E wave/A wave peak velocities ratio between the group with intrahepatic cholestasis of pregnancy and the healthy pregnant group (weighted mean difference, 0.01; 95% confidence interval, -0.03 to 0.05).

CONCLUSION

Our findings supported the idea that intrahepatic cholestasis of pregnancy is associated with overall impaired fetal myocardial performance and impaired fetal cardiac conduction system. However, current evidence about the association between fetal cardiac dysfunction and intrahepatic cholestasis of pregnancy-induced stillbirth is lacking. Further studies are needed to reveal the relationship between fetal cardiac dysfunction and adverse perinatal outcomes in pregnancies complicated by intrahepatic cholestasis of pregnancy.

Effects of elevated bile acid levels on fetal myocardium in intrahepatic cholestasis of pregnancy, a retrospective study from a neonatal perspective

AIM

Intrahepatic cholestasis of pregnancy (ICP) is a liver disease which may lead to a sudden fetal death.Previous studies have suggested that the fetal accident may be related to their cardiac dysfunction.However,the relationship between fetal cardiac dysfunction and their maternal bile acid levels is not clear.This objective was to clarify the relationship from a neonatal perspective and to furtherly make clear the aftereffect by analyzing the cardiac parameters of the older neonates.

METHODS

In this case-control study,patients and their neonates,managed between 10 September 2018 and 30 June 2021 at a Chinese university hospital center,were divided into severe ICP group,mild ICP group and control gestational group.The maternal bile acid levels and the cardiac paramerers of one-day-old neonates and five-day-old neonates were analyzed,respectively.

RESULTS

The specific-myocardial enzyme(CK-MB) and left ventricular fraction shortening(FS) of neonates showed significant difference between ICP group and control group, and were meaningfully correlated with maternal bile acid levels.However,There was no significant difference in cardiac injury parameters of older neonates between the ICP group and control group.

CONCLUSIONS

The elevated maternal bile acid levels can lead to fetal myocardial injury and the injury can be recovered after removel from high concentrations of bile acid.

Fetal cardiac dysfunction in pregnancies affected by intrahepatic cholestasis of pregnancy: A cohort study

AIM

To analyze the presence of fetal myocardial dysfunction in intrahepatic cholestasis of pregnancy (ICP) at diagnosis.

METHODS

This prospective cohort study included 49 pregnant participants with ICP at diagnosis and 49 nonaffected controls from a single public hospital. ICP was diagnosed based on clinical symptoms after excluding other causes of pruritus and presence of autoimmune diseases. Total bile acids were not obtained in this cohort. ICP pregnancies were assessed with a functional echocardiography at diagnosis including PR-interval, isovolumetric contraction time (ICT), ejection time (ET), and isovolumetric relaxation time (IRT) for electrical, systolic, and diastolic function, respectively. Controls were assessed at recruitment. Perinatal outcomes were obtained from delivery books. The main outcome was the presence of PR-interval prolongation or first-degree fetal heart block, and echographic signs of diastolic and systolic dysfunction.

RESULTS

Compared to controls, ICP were above upper limit in conjugated bilirubin (2.0% vs. 20.4%; p = 0.008), aspartate aminotransferase (2.0% vs. 24.5%; p = 0.002), and alanine aminotransferase (4.1% vs. 28.6%; p = 0.002). ICP was associated with a higher PR-interval (130 ± 12 ms vs. 121 ± 6 ms; p < 0.0001) with five first-degree fetal heart blocks. IRT was significantly higher in ICP (42 ± 6 ms vs. 37 ± 5 ms; p = 0.0001), with no differences in ICT and ET. PR-interval trend was only positively correlated with IRT in ICP pregnancies (p = 0.04 and p = 0.34, in ICP and controls, respectively).

CONCLUSIONS

Our study demonstrates that fetuses affected by maternal ICP are associated with electrical and diastolic myocardial dysfunction. More studies focused on antenatal and postnatal functional echocardiography are necessary to validate our results and consider these markers in the clinical management of ICP pregnancies.

The Role of Bile Acids in Cardiovascular Diseases: from Mechanisms to Clinical Implications

Bile acids (BAs), key regulators in the metabolic network, are not only involved in lipid digestion and absorption but also serve as potential therapeutic targets for metabolic disorders. Studies have shown that cardiac dysfunction is associated with abnormal BA metabolic pathways. As ligands for several nuclear receptors and membrane receptors, BAs systematically regulate the homeostasis of metabolism and participate in cardiovascular diseases (CVDs), such as myocardial infarction, diabetic cardiomyopathy, atherosclerosis, arrhythmia, and heart failure. However, the molecular mechanism by which BAs trigger CVDs remains controversial. Therefore, the regulation of BA signal transduction by modulating the synthesis and composition of BAs is an interesting and novel direction for potential therapies for CVDs. Here, we mainly summarized the metabolism of BAs and their role in cardiomyocytes and noncardiomyocytes in CVDs. Moreover, we comprehensively discussed the clinical prospects of BAs in CVDs and analyzed the clinical diagnostic and application value of BAs. The latest development prospects of BAs in the field of new drug development are also prospected. We aimed to elucidate the underlying mechanism of BAs treatment in CVDs, and the relationship between BAs and CVDs may provide new avenues for the prevention and treatment of these diseases.

Molecular Pathogenesis of Intrahepatic Cholestasis of Pregnancy

Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy-specific liver disease. The maternal symptoms are characterized by skin pruritus and elevated bile acids, causing several adverse outcomes for fetuses, including an increased risk of preterm birth, meconium-stained amniotic fluid, neonatal depression, respiratory distress syndrome, and stillbirth. Genetic, hormonal, immunological, and environmental factors contribute to the pathogenesis of ICP, and the estrogen-bile acid axis is thought to play a dominant role. The advances in the past 10 years uncover more details of this axis. Moreover, dysregulation of extracellular matrix and oxygen supply, organelle dysfunction, and epigenetic changes are also found to cause ICP, illuminating more potential drug targets for interfering with. Here, we summarize the molecular pathogenesis of ICP with an emphasis on the advancement in the past 10 years, aiming to give an updated full view of this field.

Fetal cardiac dysfunction in intrahepatic cholestasis of pregnancy is associated with elevated serum bile acid concentrations

BACKGROUND & AIMS

Intrahepatic cholestasis of pregnancy (ICP) is associated with an increased risk of stillbirth. This study aimed to assess the relationship between bile acid concentrations and fetal cardiac dysfunction in patients with ICP who were or were not treated with ursodeoxycholic acid (UDCA).

METHODS

Bile acid profiles and NT-proBNP, a marker of ventricular dysfunction, were assayed in umbilical venous serum from 15 controls and 76 ICP cases (36 untreated, 40 UDCA-treated). Fetal electrocardiogram traces were obtained from 43 controls and 48 ICP cases (26 untreated, 22 UDCA-treated). PR interval length and heart rate variability (HRV) parameters were measured in 2 behavioral states (quiet and active sleep).

RESULTS

In untreated ICP, fetal total serum bile acid (TSBA) concentrations (r = 0.49, p = 0.019), hydrophobicity index (r = 0.20, p = 0.039), glycocholate concentrations (r = 0.56, p = 0.007) and taurocholate concentrations (r = 0.44, p = 0.039) positively correlated with fetal NT-proBNP. Maternal TSBA (r = 0.40, p = 0.026) and alanine aminotransferase (r = 0.40, p = 0.046) also positively correlated with fetal NT-proBNP. There were no significant correlations between maternal or fetal serum bile acid concentrations and fetal HRV parameters or NT-proBNP concentrations in the UDCA-treated cohort. Fetal PR interval length positively correlated with maternal TSBA in untreated (r = 0.46, p = 0.027) and UDCA-treated ICP (r = 0.54, p = 0.026). Measures of HRV in active sleep and quiet sleep were significantly higher in untreated ICP cases than controls. HRV values in UDCA-treated cases did not differ from controls.

CONCLUSIONS

Elevated fetal and maternal serum bile acid concentrations in untreated ICP are associated with an abnormal fetal cardiac phenotype characterized by increased NT-proBNP concentration, PR interval length and HRV. UDCA treatment partially attenuates this phenotype.

LAY SUMMARY

The risk of stillbirth in intrahepatic cholestasis of pregnancy (ICP) is linked to the level of bile acids in the mother which are thought to disrupt the baby's heart rhythm. We found that babies of women with untreated ICP have abnormally functioning hearts compared to those without ICP, and the degree of abnormality is closely linked to the level of harmful bile acids in the mother and baby's blood. Babies of women with ICP who received treatment with the drug UDCA do not have the same level of abnormality in their hearts, suggesting that UDCA could be a beneficial treatment in some ICP cases, although further clinical trials are needed to confirm this.

[Intrahepatic cholestasis of pregnancy]

Die Schwangerschaftscholestase („intrahepatic cholestasis of pregnancy“, ICP) ist die häufigste schwangerschaftsspezifische Lebererkrankung. Das Leitsymptom Juckreiz sowie eine begleitende Serumkonzentrationserhöhung von Gallensäuren und/oder der Alaninaminotransferase (ALT) sind wegweisend in der Diagnosestellung. Die mütterliche Prognose ist gut. Das fetale Outcome ist abhängig von der Gallensäurenkonzentration. Die ICP ist dabei sowohl mit Frühgeburt als auch mit intrauterinem Fruchttod (IUFT) assoziiert. Dieser ist Folge einer akuten fetalen Asphyxie, nicht einer chronischen uteroplazentaren Dysfunktion. Ein prädiktives Monitoring, z. B. durch Kardiotokographie (CTG) oder Ultraschall gibt es nicht. Eine medikamentöse Therapie mit Ursodeoxycholsäure (UDCA) bessert den Juckreiz, aber beeinflusst das fetale Outcome nicht nachweislich. Eine Entbindungsindikation ist in Abhängigkeit von Gallensäurenkonzentration und Gestationsalter gegeben. In Folgeschwangerschaften besteht ein hohes Wiederholungsrisiko.

Assessment of Mechanical Fetal PR Interval in Intrahepatic Cholestasis of Pregnancy and Its Relationship with the Severity of the Disease

OBJECTIVE

This study aimed to investigate the fetal atrioventricular conduction system in intrahepatic cholestasis of pregnancy (ICP) by measuring the fetal mechanical PR interval and to explore the significance of predicting the severity of the disease.

STUDY DESIGN

Forty pregnant women diagnosed with ICP, classified as severe and mild, and 40 healthy pregnant women participated in the study. Fetal mechanical PR interval was calculated, and fetal mechanical PR interval and neonatal outcome were compared between the groups. The relationship between the mechanical PR interval and the severity of ICP was analyzed.

RESULTS

The fetal mechanical PR interval was significantly longer in the ICP group than in the control group (p < 0.005). Likewise, laboratory parameters such as transaminases (alanine aminotransferase [ALT], aspartate aminotransferase [AST]) and total bilirubin levels were significantly higher in the ICP group (p < 0.005).There were no statistically significant differences in the fetal complications. There was a positive correlation between the severity of disease and fetal PR interval.

CONCLUSION

A prolonged fetal mechanical PR interval in fetuses of mothers with ICP was demonstrated in this study. It was also shown that there was a positive correlation between fetal PR interval and severity of the disease. The study concluded that fetal mechanical PR interval measurement can be used to predict the severity of disease in ICP.

Prolonged ursodeoxycholic acid administration reduces acute ischaemia-induced arrhythmias in adult rat hearts

Acute myocardial ischaemia and reperfusion (I-R) are major causes of ventricular arrhythmias in patients with a history of coronary artery disease. Ursodeoxycholic acid (UDCA) has previously been shown to be antiarrhythmic in fetal hearts. This study was performed to investigate if UDCA protects against ischaemia-induced and reperfusion-induced arrhythmias in the adult myocardium, and compares the effect of acute (perfusion only) versus prolonged (2 weeks pre-treatment plus perfusion) UDCA administration. Langendorff-perfused adult Sprague-Dawley rat hearts were subjected to acute regional ischaemia by ligation of the left anterior descending artery (10 min), followed by reperfusion (2 min), and arrhythmia incidence quantified. Prolonged UDCA administration reduced the incidence of acute ischaemia-induced arrhythmias (p = 0.028), with a reduction in number of ventricular ectopic beats during the ischaemic phase compared with acute treatment (10 ± 3 vs 58 ± 15, p = 0.036). No antiarrhythmic effect was observed in the acute UDCA administration group. Neither acute nor prolonged UDCA treatment altered the incidence of reperfusion arrhythmias. The antiarrhythmic effect of UDCA may be partially mediated by an increase in cardiac wavelength, due to the attenuation of conduction velocity slowing (p = 0.03), and the preservation of Connexin43 phosphorylation during acute ischaemia (p = 0.0027). The potential antiarrhythmic effects of prolonged UDCA administration merit further investigation.

Effects of intrahepatic cholestasis of pregnancy on hepatic function, changes of inflammatory cytokines and fetal outcomes

The effects of intrahepatic cholestasis of pregnancy (ICP) on hepatic function, changes of inflammatory cytokines and fetal outcomes were studied. In total, 663 pregnant women admitted to Daqing Longnan Hospital from July 2016 to December 2017 were selected. There were, 40 cases with ICP enrolled in the observation group, and 40 normal pregnant women were recruited in the normal group. They were also grouped according to hepatic function and inflammatory cytokines, with 40 cases in each group. Neonatal Apgar scores were recorded. The correlations of serum cholylglycine (CG) in pregnant women with umbilical artery systolic-to-diastolic (S/D) ratio in the third trimester of pregnancy, the alanine aminotransferase level, the high-sensitivity C-reactive protein (hs-CRP) level, neonatal Apgar score and gestational week were analyzed. The birth weight in the observation group was lighter than that in the normal group (P<0.05); the gestational week at birth was earlier than that in the normal group (P<0.05); Apgar score at birth was lower than that in the normal group (P<0.05), and the levels of inflammatory cytokines were higher than those in the control group (P<0.05). Apgar scores of newborns at birth and at 1 and 5 min after birth in the normal hepatic function and normal inflammatory cytokine groups were higher than those in the abnormal hepatic function group (P<0.05). The serum CG level in pregnant women was positively correlated with umbilical artery S/D ratio, the alanine aminotransferase level and the hs-CRP level in the third trimester of pregnancy, but negatively correlated with neonatal Apgar score and gestational week. Among patients with ICP, the higher the GG level in the body is, the higher the alanine aminotransferase, inflammatory cytokine and umbilical artery S/D ratio will be, which may cause lower neonatal Apgar score, neonatal asphyxia and premature delivery.