Rare variant mutations in pregnancy-associated or peripartum cardiomyopathy

Peripartum cardiomyopathy in the twenty-first century: a review of the pathophysiology and clinical trials for novel disease-specific therapeutics

Peripartum cardiomyopathy is an idiopathic and nonischemic systolic dysfunction with onset toward the end of pregnancy and up to 5 months postpartum. Its clinical phenotype overlaps with pregnancy-associated cardiomyopathy rendering both a continuum of the same disease. Incidence varies geographically and is highest in areas where risk factors are prevalent. The understanding of its pathophysiology is constantly evolving, but a proposed two-hit model of dysfunctional vasculogenesis and genetic predisposition exacerbated by the hemodynamic stressors of pregnancy is widely accepted. The catalysis of the cleavage of prolactin into an anti-angiogenic fragment provoked by unbalanced oxidative stress forms the bedrock of its pathogenesis. Furthermore, miRNA signaling, placenta-produced factors, and a potential underlying genetic susceptibility convene to disrupt cardiac and endothelial metabolic homeostasis. The role of anti-adrenergic and anti-sarcomeric antibodies, nutritional deficiency, and mutated viral cardiotropes are understudied. There are limited randomized controlled trials for disease-specific drugs; however, most trials are targeted at the D2 receptor agonist bromocriptine. Positive primary endpoints in a large German clinical trial led to its approved use in Europe, but the U.S.A. still renders it experimental with ongoing trials evaluating its long-term efficacy and safety. Despite its popularity since the 1900s, multiple gaps in evidence regarding long-term management after myocardial recovery, management of subsequent pregnancies, optimal anticoagulation strategy, and alternative pathophysiological pathways remain unknown.

Evaluation of Women with Peripartum or Dilated Cardiomyopathy and Their First-Degree Relatives: The DCM Precision Medicine Study

Background

Peripartum cardiomyopathy (PPCM) presents substantial risk of maternal mortality, but underlying cause remains unsettled.

Methods

We compared the prevalence of dilated cardiomyopathy (DCM)-relevant genetic variants in 452 female patients (probands) of African and European ancestry (AA, EA) with PPCM or DCM who had been pregnant at least once. Pathogenic and likely pathogenic (P/LP) variants were identified in DCM-associated genes. Risk of DCM or partial DCM, defined as left ventricular enlargement or a left ventricular ejection fraction of <50%, were compared in 665 FDRs of PPCM and DCM probands.

Results

The estimated prevalences of P/LP findings among 67 probands with PPCM compared to 385 probands with DCM were comparable within ancestry (for AA, 7.8% [95% CI: 0.0%-15.7%] vs. 7.8% [95% CI: 1.1%-14.4%]; for EA, 29.5% [12.5%-46.5%] vs. 29.8% [15.5%-44.2%]). The risk of DCM/partial DCM was not lower for FDRs of PPCM probands relative to FDRs of DCM probands (HR, 0.77; 95% CI, 0.47 - 1.28). For an FDR of a non-Hispanic EA proband with PPCM, the lowest estimated DCM/partial DCM risk by age 80 was 26.8% (95% CI, 15.0%-45.0%) compared to 33.2% (95% CI, 21.2%-49.5%) for an FDR of a proband with DCM. Further validating PPCM genetic risk by using a set of genes common between studies, the estimated prevalence of P/LP variants among EA PPCM probands (26.6%; 95% CI, 12.6%-40.6%) was higher than the general population estimate from a UK Biobank study (0.6%), Also, the estimated DCM prevalence among the lowest-risk FDRs of non-Hispanic EA probands with PPCM (7.0% [95% CI, 0%-14.1%] females, 9.0% [95% CI, 1.6%-16.3%] males) was higher than general population estimates from another UK Biobank study (0.30% females, 0.63% males).

Conclusions

Comparing women with PPCM to those with DCM, a similar prevalence of DCM-relevant genetic variants and similar risk of DCM or partial DCM among their first-degree relatives were observed. These findings, along with comparisons to the general population showing higher prevalence of DCM-relevant genetic variants in women with PPCM and higher DCM prevalence in their FDRs, strengthen evidence for the genetic basis of PPCM and underscore the need for clinical genetic evaluations for PPCM patients.

Clinical Trial

clinicaltrials.gov, NCT03037632.

What Do We Know about Peripartum Cardiomyopathy? Yesterday, Today, Tomorrow

Peripartum cardiomyopathy is a disease that occurs during or after pregnancy and leads to a significant decline in cardiac function in previously healthy women. Peripartum cardiomyopathy has a varying prevalence among women depending on the part of the world where they live, but it is associated with a significant mortality and morbidity in this population. Therefore, timely diagnosis, treatment, and monitoring of this disease from its onset are of utmost importance. Although many risk factors are associated with the occurrence of peripartum cardiomyopathy, such as conditions of life, age of the woman, nutrient deficiencies, or multiple pregnancies, the exact cause of its onset remains unknown. Advances in research on the genetic associations with cardiomyopathies have provided a wealth of data indicating a possible association with peripartum cardiomyopathy, but due to numerous mutations and data inconsistencies, the exact connection remains unclear. Significant insights into the pathophysiological mechanisms underlying peripartum cardiomyopathy have been provided by the theory of an abnormal 16-kDa prolactin, which may be generated in an oxidative stress environment and lead to vascular and consequently myocardial damage. Recent studies supporting this disease mechanism also include research on the efficacy of bromocriptine (a prolactin synthesis inhibitor) in restoring cardiac function in affected patients. Despite significant progress in the research of this disease, there are still insufficient data on the safety of use of certain drugs treating heart failure during pregnancy and breastfeeding. Considering the metabolic changes that occur in different stages of pregnancy and the postpartum period, determining the correct dosing regimen of medications is of utmost importance not only for better treatment and survival of mothers but also for reducing the risk of toxic effects on the fetus.

Cardiomyopathy discovered during pregnancy: Insights from speckle tracking echocardiography in a cohort of pregnant patients

BACKGROUND

Heart failure (HF) is considered the leading cause of cardiac-related morbidity and mortality during pregnancy. Peripartum cardiomyopathy (PPCM) presents diagnostic challenges, often mirroring dilated cardiomyopathy (DCM). The aim of the study is to evaluate echocardiographic features, including global and segmental longitudinal strain values, in pregnant women with a history of newly diagnosed left ventricular systolic dysfunction (LVSD) in the third trimester of pregnancy.

METHODS

This cross-sectional study, conducted in two referral cardio-obstetric clinics in Isfahan, Iran, enrolled pregnant women with newly diagnosed LV systolic dysfunction in the third trimester of pregnancy. A multidisciplinary pregnancy heart team assessed the patients. Reevaluation of patients and advanced echocardiographic investigation, including speckle tracking echocardiography (STE), were performed at least six months after delivery.

RESULTS

The study included 26 pregnant women. Baseline characteristics revealed varying NYHA functional classes and etiologies, including DCM or non-dilated LV cardiomyopathy and PPCM. Undiagnosed DCM with exacerbation during pregnancy or non-dilated LV cardiomyopathy were the most probable causes for LV systolic dysfunction (65.4%). In five cases, peripartum cardiomyopathy was more relevant. The mean global longitudinal strain (GLS) was -16.94% and -13.95% in PPCM and DCM, respectively. Significantly different regional longitudinal strain numbers among different LV segments in PPCM were observed (P=.042), whereas the segmental strain in DCM patients did not differ.

CONCLUSION

When LVSD is discovered late in pregnancy, it is not easy for the authors to differentiate between peripartum cardiomyopathy and other cardiomyopathies. Advanced echocardiographic techniques, particularly GLS analysis, may be valuable in differentiating between these conditions.

Study of heart function in PRE-Eclampsia during and after PreGnancy (SHePREG): The pilot cohort

BACKGROUND

Pre-eclampsia with severe features (severe PreE) is associated with heart dysfunction, yet the impact beyond pregnancy, including its association with cardiomyopathic genetic polymorphisms, remains poorly understood.

OBJECTIVE

We aimed to characterize the temporal impact of severe PreE on heart function through the 4th trimester in women with and without deleterious cardiomyopathic genetic variants.

METHODS

Pregnant women were enrolled to undergo transthoracic echocardiography (TTE) in late pregnancy and 3 months postpartum. In women with severe PreE a targeted approach to identify pathogenic cardiomyopathic genetic polymorphisms was undertaken, and heart function was compared in carriers and noncarriers.

RESULTS

Pregnant women (32 ± 4 years old, severe PreE = 14, control = 8) were enrolled between 2019 - 2021. Women with severe PreE displayed attenuated myocardial relaxation (mitral e' = 11.0 ± 2.2 vs 13.2 ± 2.3 cm/sec, P < .05) in late pregnancy, and on in-silico analysis, deleterious cardiomyopathic variants were found in 58%. At 103 ± 33 days postpartum, control women showed stability in myocardial relaxation (Mitral e' Entry: 13.2 ± 2.3 vs Postpartum: 13.9 ± 1.7cm/sec, P = .464), and genetic negative severe PreE women (G-) demonstrated recovery of diastolic function to control level (Mitral e' Entry: 11.0 ± 3.0 vs Postpartum 13.7 ± 2.8cm/sec, P < .001), unlike their genetic positive (G+) counterparts (Mitral e' Entry: 10.5 ± 1.7 vs Postpartum 10.8 ± 2.4cm/sec, P = .853).

CONCLUSIONS

Postpartum recovery of heart function after severe PreE is attenuated in women with deleterious cardiomyopathic genetic polymorphisms.

The genetic basis for adult-onset idiopathic dilated cardiomyopathy in people of African descent

Cardiomyopathies are a heterogeneous group of cardiac muscle disorders that result in dilated, hypertrophic, or restrictive pathophysiological entities. Dilated cardiomyopathy (DCM) is the most common form in sub-Saharan Africa (SSA). However, population-specific research studies reporting the actual burden of DCM in this region are still lacking. Also, little is known about the genetic basis of DCM in this population, and genetic testing is still not readily accessible. This review describes the common pathogenic genes implicated in DCM globally and discusses the evidence-based management of patients with DCM. We also present a summary of studies describing genes implicated or associated with DCM in patients residing in SSA.

Introducing and Implementing Genetic Assessment in Cardio-Obstetrics Clinical Practice: Clinical and Genetic Workup of Patients with Cardiomyopathy

Cardiovascular disease (CVD) during pregnancy varies significantly worldwide, influenced by factors such as access to healthcare, delayed diagnosis, causes, and risk factors. Our study sought to explore the spectrum of CVD present in pregnant women in the United Arab Emirates to better understand this population's unique needs and challenges. Central to our study is an emphasis on the importance of implementing a multidisciplinary approach that involves the collaboration of obstetricians, cardiologists, geneticists, and other healthcare professionals to ensure that patients receive comprehensive and coordinated care. This approach can also help identify high-risk patients and implement preventive measures to reduce the occurrence of adverse maternal outcomes. Furthermore, increasing awareness among women about the risk of CVD during pregnancy and obtaining detailed family histories can help in the early identification and management of these conditions. Genetic testing and family screening can also aid in identifying inherited CVD that can be passed down through families. To illustrate the significance of such an approach, we provide a comprehensive analysis of five women's cases from our retrospective study of 800 women. The findings from our study emphasize the importance of addressing maternal cardiac health in pregnancy and the need for targeted interventions and improvements in the existing healthcare system to reduce adverse maternal outcomes.

The role of temporary mechanical circulatory support in de novo heart failure syndromes with cardiogenic shock: A contemporary review

Cardiogenic shock (CS) is a complex clinical syndrome with a high mortality rate. It can occur to due to multiple etiologies of cardiovascular disease and is phenotypically heterogeneous. Acute myocardial infarction-related CS (AMI-CS) has historically been the most prevalent cause, and thus, research and guidance have focused primarily on this. Recent data suggest that the burden of non-ischemic CS is increasing in the population of patents requiring intensive care admission. There is, however, a paucity of data and guidelines to inform the management of these patients who fall into two broad groups: those with existing heart failure and CS and those with no known history of heart failure who present with "de novo" CS. The use of temporary mechanical circulatory support (MCS) has expanded across all etiologies, despite its high cost, resource intensity, complication rates, and lack of high-quality outcome data. Herein, we discuss the currently available evidence on the role of MCS in the management of patients with de novo CS to include fulminant myocarditis, right ventricular (RV) failure, Takotsubo syndrome, post-partum cardiomyopathy, and CS due to valve lesions and other cardiomyopathies.

The role of the pregnancy heart team in clinical practice

Significant maternal and fetal morbidity and mortality risk has been shown to be associated with cardiovascular disease in pregnancy. Several determinants, such as the increasing number of females with corrected congenital heart disease in reproductive age, a more advanced maternal age associated with cardiovascular risk factors, and a greater prevalence of preexisting comorbidities related to cardiac disorders such as cancer and COVID-19), lead to a higher incidence of cardiac complications in pregnancy in the last few decades. However, adopting a multidisciplinary strategy may influence maternal and neonatal outcomes. This review aims at assessing the role of the Pregnancy Heart Team, which should ensure careful pre-pregnancy counseling, pregnancy monitoring, and delivery planning for both congenital and other cardiac or metabolic disorders, addressing several emerging aspects in the multidisciplinary team-based approach.

Peripartum Cardiomyopathy: Risks Diagnosis and Management

Peripartum cardiomyopathy is a rare cause of heart failure that occurs during late pregnancy or in the early postpartum period. Delays in diagnosis may occur as symptoms of heart failure mimic those of normal pregnancy. The diagnosis should be considered in any pregnant or postpartum woman with symptoms concerning for heart failure. If there are clinical concerns, labs including N-terminal pro-BNP should be checked, and an echocardiogram should be ordered to assess for systolic dysfunction. Prompt medical treatment tailored for pregnancy and lactation is essential to prevent adverse events. Outcomes are variable, including complete recovery, persistent myocardial dysfunction with heart failure symptoms, arrhythmias, thromboembolic events, and/or rapid deterioration requiring mechanical circulatory support and cardiac transplantation. It is essential that care is provided as part of a multidisciplinary cardio-obstetrics team including obstetrics, cardiology, maternal fetal medicine, anesthesiology, and nursing. All women with peripartum cardiomyopathy should have close follow-up with a cardiologist, although optimal duration of medical therapy following complete recovery is unknown. Women considering a subsequent pregnancy require preconception counseling and close collaboration between obstetrics and cardiology throughout pregnancy.

Dilated cardiomyopathy and chronic cardiac inflammation: Pathogenesis, diagnosis and therapy

Dilated cardiomyopathy (DCM) is typically defined by left ventricular dilation and systolic dysfunction in the absence of a clear precipitant. Idiopathic disease is common; up to 50% of patients with DCM have no cause found despite imaging, genetic and biopsy assessments. Treatment remains focused on managing symptoms, reducing the risk of sudden cardiac death and ameliorating the structural and electrical complications of disease progression. In the absence of aetiology-specific treatments, the condition remains associated with a poor prognosis; mortality is approximately 40% at 10 years. The role of immune-mediated inflammatory injury in the development and progression of DCM was first proposed over 30 years ago. Despite the subsequent failures of three large clinical trials of immunosuppressive treatment (ATTACH, RENEWAL and the Myocarditis Treatment Trial), evidence for an abnormal adaptive immune response in DCM remains significant. In this review, we summarise and discuss available evidence supporting immune dysfunction in DCM, with a specific focus on cellular immunity. We also highlight current clinical and experimental treatments. We propose that the success of future immunosuppressive treatment trials in DCM will be dependent on the deep immunophenotyping of patients, to identify those with active inflammation and/or an abnormal immune response who are most likely to respond to therapy.

Peripartum Cardiomyopathy Presenting With Incessant Ventricular Arrhythmias

Sudden cardiac death is hypothesized to be one of the leading causes of mortality in peripartum cardiomyopathy. This case illustrates a patient who presented with cardiac arrest, and it discusses the importance of considering multiple causes of fulminant ventricular arrhythmias in the setting of decreased left ventricular function during the peripartum period. (Level of Difficulty: Advanced.)

Racial and Ethnic Disparities in the Trends and Outcomes of Cardiogenic Shock Complicating Peripartum Cardiomyopathy

IMPORTANCE

Cardiogenic shock (CS) is a recognized complication of peripartum cardiomyopathy (PPCM) associated with poor prognosis. Although racial and ethnic disparities have been described in the occurrence and outcomes of PPCM, it is unclear if these disparities persist among patients with PPCM and CS.

OBJECTIVES

To evaluate the temporal trends in CS incidence among hospitalized patients with PPCM stratified by race and ethnicity and to investigate the racial and ethnic differences in hospital mortality, mechanical circulatory support (MCS) use, and heart transplantation (HT).

DESIGN, SETTING, AND PARTICIPANTS

This multicenter retrospective cohort study included hospitalized patients with PPCM complicated by CS in the US from 2005 to 2019 identified from the National Inpatient Sample (NIS). Data analysis was conducted in November 2021.

EXPOSURE

PPCM complicated by CS.

MAIN OUTCOMES AND MEASURES

The main outcome was incidence of CS in PPCM stratified by race and ethnicity. The secondary outcome was racial and ethnic differences in hospital mortality, MCS use, and HT.

RESULTS

Of 55 804 hospitalized patients with PPCM, 1945 patients had CS, including 947 Black patients, 236 Hispanic patients, and 702 White patients, translating to an incidence rate of 35 CS events per 1000 patients with PPCM. The mean (SD) age was 31 (9) years. Black and Hispanic patients had higher CS incidence rates (39 events per 1000 patients with PPCM) compared with White patients (33 events per 1000 patients with PPCM). CS incidence rates significantly increased across all races and ethnicities over the study period. Overall, the odds of developing CS were higher in Black patients (aOR, 1.17 [95% CI, 1.15-1.57]; P < .001) and Hispanic patients (aOR, 1.37 [95% CI, 1.17-1.59]; P < 001) compared with White patients during the study period. Compared with White patients, the odds of in-hospital mortality were higher in Black (adjusted odds ratio [aOR], 1.67 [95% CI, 1.21-2.32]; P = .002) and Hispanic (aOR, 2.20 [95% CI, 1.45-3.33]; P < .001) patients. Hispanic patients were more likely to receive any type of MCS device (aOR, 2.23 [95% CI, 1.60-3.09]; P < .001), intraaortic balloon pump (aOR, 1.65 [95% CI, 1.11-2.44]; P < .001), and ventricular assisted device (aOR, 4.45 [95% CI, 2.45-8.08]; P < .001), compared with White patients. Black patients were more likely to receive VAD (aOR, 2.69 [95% CI, 1.63-4.42]; P < .001) compared with White patients. Black and Hispanic patients were significantly less likely to receive HT compared with White patients (Black patients: aOR, 0.51 [95% CI, 0.33-0.78]; P = .02; Hispanic patients: aOR, 0.15 [95% CI, 0.06-0.42]; P < .001).

CONCLUSIONS AND RELEVANCE

These findings highlight significant racial disparities in mortality and HT among hospitalized patients with PPCM complicated by CS in the US. More research to identify factors of racial and ethnic disparities is needed to guide interventions to improve outcomes of patients with PPCM.

Significance of α-Myosin Heavy Chain (MYH6) Variants in Hypoplastic Left Heart Syndrome and Related Cardiovascular Diseases

Hypoplastic left heart syndrome (HLHS) is a severe congenital heart disease (CHD) with complex genetic inheritance. HLHS segregates with other left ventricular outflow tract (LVOT) malformations in families, and can present as either an isolated phenotype or as a feature of a larger genetic disorder. The multifactorial etiology of HLHS makes it difficult to interpret the clinical significance of genetic variants. Specific genes have been implicated in HLHS, including rare, predicted damaging MYH6 variants that are present in >10% of HLHS patients, and which have been shown to be associated with decreased transplant-free survival in our previous studies. MYH6 (α-myosin heavy chain, α-MHC) variants have been reported in HLHS and numerous other CHDs, including LVOT malformations, and may provide a genetic link to these disorders. In this paper, we outline the MYH6 variants that have been identified, discuss how bioinformatic and functional studies can inform clinical decision making, and highlight the importance of genetic testing in HLHS.

2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure" replaces the "2013 ACCF/AHA Guideline for the Management of Heart Failure" and the "2017 ACC/AHA/HFSA Focused Update of the 2013 ACCF/AHA Guideline for the Management of Heart Failure." The 2022 guideline is intended to provide patient-centric recommendations for clinicians to prevent, diagnose, and manage patients with heart failure.

METHODS

A comprehensive literature search was conducted from May 2020 to December 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from MEDLINE (PubMed), EMBASE, the Cochrane Collaboration, the Agency for Healthcare Research and Quality, and other relevant databases. Additional relevant clinical trials and research studies, published through September 2021, were also considered. This guideline was harmonized with other American Heart Association/American College of Cardiology guidelines published through December 2021. Structure: Heart failure remains a leading cause of morbidity and mortality globally. The 2022 heart failure guideline provides recommendations based on contemporary evidence for the treatment of these patients. The recommendations present an evidence-based approach to managing patients with heart failure, with the intent to improve quality of care and align with patients' interests. Many recommendations from the earlier heart failure guidelines have been updated with new evidence, and new recommendations have been created when supported by published data. Value statements are provided for certain treatments with high-quality published economic analyses.

2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure

AIM

The "2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure" replaces the "2013 ACCF/AHA Guideline for the Management of Heart Failure" and the "2017 ACC/AHA/HFSA Focused Update of the 2013 ACCF/AHA Guideline for the Management of Heart Failure." The 2022 guideline is intended to provide patient-centric recommendations for clinicians to prevent, diagnose, and manage patients with heart failure.

METHODS

A comprehensive literature search was conducted from May 2020 to December 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from MEDLINE (PubMed), EMBASE, the Cochrane Collaboration, the Agency for Healthcare Research and Quality, and other relevant databases. Additional relevant clinical trials and research studies, published through September 2021, were also considered. This guideline was harmonized with other American Heart Association/American College of Cardiology guidelines published through December 2021.

STRUCTURE

Heart failure remains a leading cause of morbidity and mortality globally. The 2022 heart failure guideline provides recommendations based on contemporary evidence for the treatment of these patients. The recommendations present an evidence-based approach to managing patients with heart failure, with the intent to improve quality of care and align with patients' interests. Many recommendations from the earlier heart failure guidelines have been updated with new evidence, and new recommendations have been created when supported by published data. Value statements are provided for certain treatments with high-quality published economic analyses.

A bibliometric review of peripartum cardiomyopathy compared to other cardiomyopathies using artificial intelligence and machine learning

As developments in artificial intelligence and machine learning become more widespread in healthcare, their potential to transform clinical outcomes also increases. Peripartum cardiomyopathy is a rare and poorly-characterised condition that presents as heart failure in the last trimester prior to delivery or within 5-6 months postpartum. The lack of a definitive understanding of the molecular causes and clinical progress of this condition suggests that bibliometrics will be well-suited to creating new insights into this serious clinical problem. We examine similarities and differences between peripartum and its closely related familial dilated cardiomyopathy and idiopathic dilated cardiomyopathy. Using PubMed as the source of bibliometric data, we apply artificial intelligence-supported natural language processing to compare extracted data and genes association with these cardiomyopathies. Gene data were enhanced with additional metadata from third-party datasets and then analysed for their impact and specificity for peripartum cardiomyopathy. Artificial intelligence identified 14 genes that distinguished peripartum from both dilated and familial dilated cardiomyopathy. They are as follows: CTSD, RLN2, MMP23B*, SLC17A5, ST2*, PTHLH, CFH*, CFI, GPT, MR1, Rln1, SRI, STAT5A* and THBD. We then used the Human Protein Atlas website that uses affinity-purified rabbit polyclonal antibodies to identify genes that are expressed at the protein level (bold), or as RNA transcripts (*) in healthy human left ventricles. Additional analysis focussed on the full set of peripartum genes on linkage and specificity to cardiomyopathy yielded a different set of thirteen genes (bold font indicates those expressed in cardiomyocytes: PRL, RLN2, PLN, ST2, CTSD, F2, ACE, STAT3, TTN, SPP1, LGALS3, miR-146a, GNB3, SRI). This type of analysis can highlight new avenues for research, aimed at improving genomics-driven peripartum cardiomyopathy diagnosis as well as potential pathological and clinical sub-classification. We expect that this will allow for future improvements in identification, treatment and management of this condition. The first step in the application of these bibliometric-based artificial intelligence methods is to understand the current knowledge, and it is the aim of this paper to show how this might be achieved.

Arrhythmic Phenotypes Are a Defining Feature of Dilated Cardiomyopathy-Associated SCN5A Variants: A Systematic Review

BACKGROUND

Variants in the SCN5A gene, that encodes the cardiac sodium channel, Nav1.5, are associated with a highly arrhythmogenic form of dilated cardiomyopathy (DCM). Our aim was to review the phenotypes, natural history, functional effects, and treatment outcomes of DCM-associated rare SCN5A variants.

METHODS

A systematic review of reported DCM-associated rare SCN5A variants was undertaken using PubMed and Embase.

RESULTS

Eighteen SCN5A rare variants in 29 families with DCM (173 affected individuals) were identified. Eleven variants had undergone experimental evaluation, with 7 of these resulting in increased sustained current flow during the action potential (eg, increased window current) and at resting membrane potentials (eg, creation of a new gating pore current). These variants were located in transmembrane voltage-sensing domains and had a consistent phenotype characterized by frequent multifocal narrow and broad complex ventricular premature beats (VPB; 72% of affected relatives), ventricular arrhythmias (33%), atrial arrhythmias (32%), sudden cardiac death (13%), and DCM (56%). This VPB-predominant phenotype was not seen with 1 variant that increased late sodium current, or with variants that reduced peak current density or had mixed effects. In the latter groups, affected individuals mainly showed sinus node dysfunction, conduction defects, and atrial arrhythmias, with infrequent VPB and ventricular arrhythmias. DCM did not occur in the absence of arrhythmias for any variant. Twelve studies (23 total patients) reported treatment success in the VPB-predominant cardiomyopathy using sodium channel-blocking drug therapy.

CONCLUSIONS

SCN5A variants can present with a diverse spectrum of primary arrhythmic features. A majority of DCM-associated variants cause a multifocal VPB-predominant cardiomyopathy that is reversible with sodium channel blocking drug therapy. Early recognition of the distinctive phenotype and prompt genetic testing to identify variant carriers are needed. Our findings have implications for interpretation and management of SCN5A variants found in DCM patients with and without arrhythmias.

Pathophysiology and risk factors of peripartum cardiomyopathy

Peripartum cardiomyopathy (PPCM) is a potentially fatal form of idiopathic heart failure with variable prevalence across different countries and ethnic groups. The cause of PPCM is unclear, but environmental and genetic factors and pregnancy-associated conditions such as pre-eclampsia can contribute to the development of PPCM. Furthermore, animal studies have shown that impaired vascular and metabolic function might be central to the development of PPCM. A better understanding of the pathogenic mechanisms involved in the development of PPCM is necessary to establish new therapies that can improve the outcomes of patients with PPCM. Pregnancy hormones tightly regulate a plethora of maternal adaptive responses, including haemodynamic, structural and metabolic changes in the cardiovascular system. In patients with PPCM, the peripartum period is associated with profound and rapid hormonal fluctuations that result in a brief period of disrupted cardiovascular (metabolic) homeostasis prone to secondary perturbations. In this Review, we discuss the latest studies on the potential pathophysiological mechanisms of and risk factors for PPCM, with a focus on maternal cardiovascular changes associated with pregnancy. We provide an updated framework to further our understanding of PPCM pathogenesis, which might lead to an improvement in disease definition.

Dyspnea and COVID-19: A Review of Confounding Diagnoses during the Postpartum Period

The puerperium is a complex period that begins with placental delivery and lasts for 6 weeks, during which readaptation of the female organism and redistribution of blood volume occur. This period is conducive to the occurrence of thromboembolic events. In the context of the SARS-CoV-2 pandemic, the virus responsible for COVID-19, the attention of the scientific community and health professionals has been focused on obtaining insights on different aspects of this disease, including etiology, transmission, diagnosis, and treatment. Regarding the pregnancy-postpartum cycle, it is opportune to review the clinical conditions that can occur during this period and to investigate dyspnea as a postpartum symptom in order to avoid its immediate association with COVID-19 without further investigation, which can lead to overlooking the diagnosis of other important and occasionally fatal conditions.

The Potential of Gamma Secretase as a Therapeutic Target for Cardiac Diseases

Heart diseases are some of the most common and pressing threats to human health worldwide. The American Heart Association and the National Institute of Health jointly work to annually update data on cardiac diseases. In 2018, 126.9 million Americans were reported as having some form of cardiac disorder, with an estimated direct and indirect total cost of USD 363.4 billion. This necessitates developing therapeutic interventions for heart diseases to improve human life expectancy and economic relief. In this review, we look into gamma-secretase as a potential therapeutic target for cardiac diseases. Gamma-secretase, an aspartyl protease enzyme, is responsible for the cleavage and activation of a number of substrates that are relevant to normal cardiac development and function as found in mutation studies. Some of these substrates are involved in downstream signaling processes and crosstalk with pathways relevant to heart diseases. Most of the substrates and signaling events we explored were found to be potentially beneficial to maintain cardiac function in diseased conditions. This review presents an updated overview of the current knowledge on gamma-secretase processing of cardiac-relevant substrates and seeks to understand if the modulation of gamma-secretase activity would be beneficial to combat cardiac diseases.

Effects of bromocriptine in peripartum cardiomyopathy: a systematic review and meta-analysis

Peripartum cardiomyopathy (PPCM) is a rare but potentially life-threatening form of heart failure (HF). Bromocriptine, a dopamine D2 agonist, has been used as an adjunctive treatment for PPCM with controversial benefits. A comprehensive literature search was conducted through June 2021. We included studies comparing the outcomes of PPCM with or without bromocriptine use. Pooled risk ratio (RR) with 95% confidence intervals (CI) and I² statistics were calculated. Composite major adverse outcomes were defined by a composite of death, need for advanced HF therapies, persistent New York Heart Association (NYHA) functional class III/V, or left ventricular ejection fraction (LVEF) ≤ 35% at 6-month follow-up. LVEF recovery was defined by improvement of LVEF to more than 50%. Eight studies (two randomized-controlled, six observational) involving 593 PPCM patients were included. Bromocriptine use was associated with significantly higher survival (91.6% vs. 83.9%, RR 1.11 p = 0.02). Baseline LVEF was not significantly different between the groups. LVEF at follow-up was significantly higher in the bromocriptine group (53.3% vs. 41.8%, p < 0.001). There was no significant association between bromocriptine use and lower composite major adverse outcomes (13.7% vs. 33.3%, RR 0.60 p = 0.54) or LVEF recovery (46.9% vs. 46.8%, RR 0.94 p = 0.74). In conclusion, the addition of bromocriptine to standard HF treatment in PPCM was associated with significantly higher survival and higher LVEF improvement. No association with lower composite adverse clinical outcomes or LVEF recovery was seen. The findings, although encouraging, warrant larger randomized-controlled studies.

Inhibition of cardiac PERK signaling promotes peripartum cardiac dysfunction

Peripartum cardiomyopathy (PPCM) is a life-threatening heart failure occurring in the peripartum period. Although mal-angiogenesis, induced by the 16-kDa N-terminal prolactin fragment (16 K PRL), is involved in the pathogenesis, the effect of full-length prolactin (23 K PRL) is poorly understood. We transfected neonate rat cardiomyocytes with plasmids containing 23 K PRL or 16 K PRL in vitro and found that 23 K PRL, but not 16 K PRL, upregulated protein kinase RNA-like endoplasmic reticulum kinase (PERK) signaling, and hypoxia promoted this effect. During the perinatal period, cardiomyocyte-specific PERK homogenous knockout (CM-KO) mice showed PPCM phenotypes after consecutive deliveries. Downregulation of PERK or JAK/STAT signaling and upregulation of apoptosis were observed in CM-KO mouse hearts. Moreover, in bromocriptine-treated CM-KO mice, cardiac function did not improve and cardiomyocyte apoptosis was not suppressed during the peripartum period. These results demonstrate that interaction between 23 K PRL and PERK signaling is cardioprotective during the peripartum term.

Peripartum cardiomyopathy: from genetics to management

Peripartum cardiomyopathy (PPCM) is a disease that occurs globally in all ethnic groups and should be suspected in any peripartum women presenting with symptoms and signs of heart failure, towards the end of pregnancy or in the months following delivery, with confirmed left ventricular dysfunction. After good history taking, all women should be thoroughly assessed, and alternative causes should be excluded. Urgent cardiac investigations with electrocardiogram and natriuretic peptide measurement (if available) should be performed. Echocardiography follows as the next step in investigation. Patients with abnormal cardiac investigations should be urgently referred to a cardiology team for expert management. Referral for genetic work-up should be considered if there is a family history of cardiomyopathy or sudden death. PPCM is a disease with substantial maternal and neonatal morbidity and mortality. Maternal mortality rates range widely, from 0% to 30%, depending on the ethnic background and geographic region. Just under half of women experience myocardial recovery. Remarkable advances in the comprehension of the pathogenesis and in patient management and therapy have been achieved, largely due to team efforts and close collaboration between basic scientists, cardiologists, intensive care specialists, and obstetricians. This review summarizes current knowledge of PPCM genetics, pathophysiology, diagnostic approach, management, and outcome.

Evidence-Based Assessment of Genes in Dilated Cardiomyopathy

BACKGROUND

Each of the cardiomyopathies, classically categorized as hypertrophic cardiomyopathy, dilated cardiomyopathy (DCM), and arrhythmogenic right ventricular cardiomyopathy, has a signature genetic theme. Hypertrophic cardiomyopathy and arrhythmogenic right ventricular cardiomyopathy are largely understood as genetic diseases of sarcomere or desmosome proteins, respectively. In contrast, >250 genes spanning >10 gene ontologies have been implicated in DCM, representing a complex and diverse genetic architecture. To clarify this, a systematic curation of evidence to establish the relationship of genes with DCM was conducted.

METHODS

An international panel with clinical and scientific expertise in DCM genetics evaluated evidence supporting monogenic relationships of genes with idiopathic DCM. The panel used the Clinical Genome Resource semiquantitative gene-disease clinical validity classification framework with modifications for DCM genetics to classify genes into categories on the basis of the strength of currently available evidence. Representation of DCM genes on clinically available genetic testing panels was evaluated.

RESULTS

Fifty-one genes with human genetic evidence were curated. Twelve genes (23%) from 8 gene ontologies were classified as having definitive (BAG3, DES, FLNC, LMNA, MYH7, PLN, RBM20, SCN5A, TNNC1, TNNT2, TTN) or strong (DSP) evidence. Seven genes (14%; ACTC1, ACTN2, JPH2, NEXN, TNNI3, TPM1, VCL) including 2 additional ontologies were classified as moderate evidence; these genes are likely to emerge as strong or definitive with additional evidence. Of these 19 genes, 6 were similarly classified for hypertrophic cardiomyopathy and 3 for arrhythmogenic right ventricular cardiomyopathy. Of the remaining 32 genes (63%), 25 (49%) had limited evidence, 4 (8%) were disputed, 2 (4%) had no disease relationship, and 1 (2%) was supported by animal model data only. Of the 16 evaluated clinical genetic testing panels, most definitive genes were included, but panels also included numerous genes with minimal human evidence.

CONCLUSIONS

In the curation of 51 genes, 19 had high evidence (12 definitive/strong, 7 moderate). It is notable that these 19 genes explain only a minority of cases, leaving the remainder of DCM genetic architecture incompletely addressed. Clinical genetic testing panels include most high-evidence genes; however, genes lacking robust evidence are also commonly included. We recommend that high-evidence DCM genes be used for clinical practice and that caution be exercised in the interpretation of variants in variable-evidence DCM genes.

Myopathic Cardiac Genotypes Increase Risk for Myocarditis

Impairments in certain cardiac genes confer risk for myocarditis in children. To determine the extent of this association, we performed genomic sequencing in predominantly adult patients with acute myocarditis and matched control subjects. Putatively deleterious variants in a broad set of cardiac genes were found in 19 of 117 acute myocarditis cases vs 34 of 468 control subjects (P = 0.003). Thirteen genes classically associated with cardiomyopathy or neuromuscular disorders with cardiac involvement were implicated, including >1 associated damaging variant in DYSF, DSP, and TTN. Phenotypes of subjects who have acute myocarditis with or without deleterious variants were similar, indicating that genetic testing is necessary to differentiate them.

Peripartum cardiomyopathy: a review

Peripartum cardiomyopathy is a form of idiopathic systolic heart failure which occurs during the end of pregnancy or the early post-partum in the absence of an identifiable etiology. The exact pathogenesis remains unknown, and the incidence is higher in African ancestry, multiparous and hypertensive women, or older maternal age. Delay in diagnosis is common, mainly because symptoms of heart failure mimic those of normal pregnancy. Echocardiography showing decreased myocardial function is at the center of the diagnosis. Management relies on the general guidelines of management of other forms of non-ischemic cardiomyopathy; however, special attention should be paid when choosing medications to ensure fetal safety. Outcomes can be variable and can range from complete recovery to persistent heart failure requiring transplant or even death. High rates of relapse with subsequent pregnancies can occur, especially with incomplete myocardial recovery. Additional research about the etiology, experimental drugs, prognosis, and duration of treatment after recovery are needed.

Heat Shock Proteins: Potential Modulators and Candidate Biomarkers of Peripartum Cardiomyopathy

Peripartum cardiomyopathy (PPCM) is a potentially life-threatening condition in which heart failure and systolic dysfunction occur late in pregnancy or within months following delivery. To date, no reliable biomarkers or therapeutic interventions for the condition exist, thus necessitating an urgent need for identification of novel PPCM drug targets and candidate biomarkers. Leads for novel treatments and biomarkers are therefore being investigated worldwide. Pregnancy is generally accompanied by dramatic hemodynamic changes, including a reduced afterload and a 50% increase in cardiac output. These increased cardiac stresses during pregnancy potentially impair protein folding processes within the cardiac tissue. The accumulation of misfolded proteins results in increased toxicity and cardiac insults that trigger heart failure. Under stress conditions, molecular chaperones such as heat shock proteins (Hsps) play crucial roles in maintaining cellular proteostasis. Here, we critically assess the potential role of Hsps in PPCM. We further predict specific associations between the Hsp types Hsp70, Hsp90 and small Hsps with several proteins implicated in PPCM pathophysiology. Furthermore, we explore the possibility of select Hsps as novel candidate PPCM biomarkers and drug targets. A better understanding of how these Hsps modulate PPCM pathogenesis holds promise in improving treatment, prognosis and management of the condition, and possibly other forms of acute heart failure.

The Complex and Diverse Genetic Architecture of Dilated Cardiomyopathy

Our insight into the diverse and complex nature of dilated cardiomyopathy (DCM) genetic architecture continues to evolve rapidly. The foundations of DCM genetics rest on marked locus and allelic heterogeneity. While DCM exhibits a Mendelian, monogenic architecture in some families, preliminary data from our studies and others suggests that at least 20% to 30% of DCM may have an oligogenic basis, meaning that multiple rare variants from different, unlinked loci, determine the DCM phenotype. It is also likely that low-frequency and common genetic variation contribute to DCM complexity, but neither has been examined within a rare variant context. Other types of genetic variation are also likely relevant for DCM, along with gene-by-environment interaction, now established for alcohol- and chemotherapy-related DCM. Collectively, this suggests that the genetic architecture of DCM is broader in scope and more complex than previously understood. All of this elevates the impact of DCM genetics research, as greater insight into the causes of DCM can lead to interventions to mitigate or even prevent it and thus avoid the morbid and mortal scourge of human heart failure.

Sex-Biased lncRNA Signature in Fetal Growth Restriction (FGR)

Impaired fetal growth is one of the most important causes of prematurity, stillbirth and infant mortality. The pathogenesis of idiopathic fetal growth restriction (FGR) is poorly understood but is thought to be multifactorial and comprise a range of genetic causes. This research aimed to investigate non-coding RNAs (lncRNAs) in the placentas of male and female fetuses affected by FGR. RNA-Seq data were analyzed to detect lncRNAs, their potential target genes and circular RNAs (circRNAs); a differential analysis was also performed. The multilevel bioinformatic analysis enabled the detection of 23,137 placental lncRNAs and 4263 of them were classified as novel. In FGR-affected female fetuses’ placentas (ff-FGR), among 19 transcriptionally active regions (TARs), five differentially expressed lncRNAs (DELs) and 12 differentially expressed protein-coding genes (DEGs) were identified. Within 232 differentially expressed TARs identified in male fetuses (mf-FGR), 33 encompassed novel and 176 known lncRNAs, and 52 DEGs were upregulated, while 180 revealed decreased expression. In ff-FGR ACTA2-AS1, lncRNA expression was significantly correlated with five DEGs, and in mf-FGR, 25 TARs were associated with DELs correlated with 157 unique DEGs. Backsplicing circRNA processes were detected in the range of H19 lncRNA, in both ff- and mf-FGR placentas. The performed global lncRNAs characteristics in terms of fetal sex showed dysregulation of DELs, DEGs and circRNAs that may affect fetus growth and pregnancy outcomes. In female placentas, DELs and DEGs were associated mainly with the vasculature, while in male placentas, disturbed expression predominantly affected immune processes.

Risk stratification and management of women with cardiomyopathy/heart failure planning pregnancy or presenting during/after pregnancy: a position statement from the Heart Failure Association of the European Society of Cardiology Study Group on Peripartum Cardiomyopathy

This position paper focusses on the pathophysiology, diagnosis and management of women diagnosed with a cardiomyopathy, or at risk of heart failure (HF), who are planning to conceive or present with (de novo or previously unknown) HF during or after pregnancy. This includes the heterogeneous group of heart muscle diseases such as hypertrophic, dilated, arrhythmogenic right ventricular and non-classified cardiomyopathies, left ventricular non-compaction, peripartum cardiomyopathy, Takotsubo syndrome, adult congenital heart disease with HF, and patients with right HF. Also, patients with a history of chemo-/radiotherapy for cancer or haematological malignancies need specific pre-, during and post-pregnancy assessment and counselling. We summarize the current knowledge about pathophysiological mechanisms, including gene mutations, clinical presentation, diagnosis, and medical and device management, as well as risk stratification. Women with a known diagnosis of a cardiomyopathy will often require continuation of drug therapy, which has the potential to exert negative effects on the foetus. This position paper assists in balancing benefits and detrimental effects.

Genetics of Peripartum Cardiomyopathy: Current Knowledge, Future Directions and Clinical Implications

Peripartum cardiomyopathy (PPCM) is a condition in which heart failure and systolic dysfunction occur late in pregnancy or within months following delivery. Over the last decade, genetic advances in heritable cardiomyopathy have provided new insights into the role of genetics in PPCM. In this review, we summarise current knowledge of the genetics of PPCM and potential avenues for further research, including the role of molecular chaperone mutations in PPCM. Evidence supporting a genetic basis for PPCM has emanated from observations of familial disease, overlap with familial dilated cardiomyopathy, and sequencing studies of PPCM cohorts. Approximately 20% of PPCM patients screened for cardiomyopathy genes have an identified pathogenic mutation, with TTN truncations most commonly implicated. As a stress-associated condition, PPCM may be modulated by molecular chaperones such as heat shock proteins (Hsps). Recent studies have led to the identification of Hsp mutations in a PPCM model, suggesting that variation in these stress-response genes may contribute to PPCM pathogenesis. Although some Hsp genes have been implicated in dilated cardiomyopathy, their roles in PPCM remain to be determined. Additional areas of future investigation may include the delineation of genotype-phenotype correlations and the screening of newly-identified cardiomyopathy genes for their roles in PPCM. Nevertheless, these findings suggest that the construction of a family history may be advised in the management of PPCM and that genetic testing should be considered. A better understanding of the genetics of PPCM holds the potential to improve treatment, prognosis, and family management.

Mitochondrial Function and Dysfunction in Dilated Cardiomyopathy

Cardiac tissue requires a persistent production of energy in order to exert its pumping function. Therefore, the maintenance of this function relies on mitochondria that represent the “powerhouse” of all cardiac activities. Mitochondria being one of the key players for the proper functioning of the mammalian heart suggests continual regulation and organization. Mitochondria adapt to cellular energy demands via fusion-fission events and, as a proof-reading ability, undergo mitophagy in cases of abnormalities. Ca²⁺ fluxes play a pivotal role in regulating all mitochondrial functions, including ATP production, metabolism, oxidative stress balance and apoptosis. Communication between mitochondria and others organelles, especially the sarcoplasmic reticulum is required for optimal function. Consequently, abnormal mitochondrial activity results in decreased energy production leading to pathological conditions. In this review, we will describe how mitochondrial function or dysfunction impacts cardiac activities and the development of dilated cardiomyopathy.

Maternal Morbidity and Mortality: Are We Getting to the "Heart" of the Matter?

Cardiovascular disease (CVD), including hypertensive disorders of pregnancy (HDP) and peripartum cardiomyopathy, is a leading cause of pregnancy-related death in the United States. Women who are African American or American Indian/Alaskan Native, have HDP, are medically underserved, are older, or are obese have a major risk for the onset and/or progression of CVD during and after pregnancy. Paradoxically, women with no preexisting chronic conditions or risk factors also experience significant pregnancy-related cardiovascular (CV) complications. The question remains whether substantial physiologic stress on the CV system during pregnancy reflected in hemodynamic, hematological, and metabolic changes uncovers subclinical prepregnancy CVD in these otherwise healthy women. Equally important and similarly understudied is the concept that women's long-term CV health could be detrimentally affected by adverse pregnancy outcomes, such as preeclampsia, gestational hypertension, and diabetes, and preterm birth. Thus, a critical life span perspective in the assessment of women's CV risk factors is needed to help women and health care providers recognize and appreciate not only optimal CV health but also risk factors present before, during, and after pregnancy. In this review article, we highlight new advancements in understanding adverse, pregnancy-related CV conditions and will discuss promising strategies or interventions for their prevention, diagnosis, and treatment.

Considering complexity in the genetic evaluation of dilated cardiomyopathy

Dilated cardiomyopathy (DCM) is a cardiovascular disease of genetic aetiology that causes substantial morbidity and mortality, and presents considerable opportunity for disease mitigation and prevention in those at risk. Foundational to the process of caring for patients diagnosed with DCM is a clinical genetic evaluation, which always begins with a comprehensive family history and clinical evaluation. Genetic testing of the proband, the first patient identified in a family with DCM, within the context of genetic counselling is always indicated, regardless of whether the DCM is familial or non-familial. Clinical screening of at-risk family members is also indicated, as is cascade genetic testing for actionable variants found at genetic testing in the proband. Clinicians now have expansive panels with many genes available for DCM genetic testing, and the approaches used to evaluate rare variants to decide which are disease-causing continues to rapidly evolve. Despite these recent advances, only a minority of cases yield actionable variants, even in familial DCM where a genetic aetiology is highly likely. This underscores that our knowledge of DCM clinical genetics remains incomplete, including variant interpretation and DCM genetic architecture. Emerging data suggest that the single-variant Mendelian disease model is insufficient to explain some DCM cases, and rather that multiple variants, both common and rare, and at times key environmental factors, interact to cause DCM. A simple model illustrating the intersection of DCM genetic architecture with environmental impact is provided.

Clinical Implications of the Genetic Architecture of Dilated Cardiomyopathy

PURPOSE OF REVIEW

Dilated cardiomyopathy (DCM) frequently involves an underlying genetic etiology, but the clinical approach for genetic diagnosis and application of results in clinical practice can be complex.

RECENT FINDINGS

International sequence databases described the landscape of genetic variability across populations, which informed guidelines for the interpretation of DCM gene variants. New evidence indicates that loss-of-function mutations in filamin C (FLNC) contribute to DCM and portend high risk of ventricular arrhythmia. A clinical framework aids in referring patients for DCM genetic testing and applying results to patient care. Results of genetic testing can change medical management, particularly in a subset of genes that increase risk for life-threatening ventricular arrhythmias, and can influence decisions for defibrillator therapy. Clinical screening and cascade genetic testing of family members should be diligently pursued to identify those at risk of developing DCM.

Unveiling the Mystery of Peripartum Cardiomyopathy: A Traditional Review

Peripartum cardiomyopathy (PPCM) can be classified as a variant of dilated cardiomyopathy identified usually within the first five months of delivery or during the last month of pregnancy. This condition presents as systolic heart failure. PPCM affects thousands of women in the United States each year. Even though it was first noticed in the 1800s, its etiology remains unknown. This study aims to review the pathophysiology and management of PPCM and explore the possible outcomes of peripartum cardiomyopathy. PPCM can lead to maternal death if diagnosis or treatment is delayed. Diagnosing PPCM has been challenging because it can be misdiagnosed or perceived as a sign of pregnancy since most of the symptoms of PPCM strongly match those within the typical pregnancy continuum and postpartum cycle. Patients' implications are fatal and carry a high mortality rate when PPCM is misdiagnosed or treatment is delayed. To accurately identify PPCM, using echocardiography, the left ventricular end-diastolic size and the ejection fraction should be measured to determine the severity of PPCM. Managing peripartum cardiomyopathy involves using traditional treatments for heart failure. Therapeutic recommendations are made depending on the patient's status (pregnancy, breastfeeding, postpartum) while considering the drug-safety profiles before administration. Some other treatments have also been used to control PPCM depending on how severe it has become; for example, antiarrhythmics have been used to treat cardiac arrhythmias when they ensue. In extreme cases, mechanical assistance and transplantation could be required. Based on the proposed pathophysiology involving the 16kDA anti-angiogenic sub-fragment, bromocriptine may be used even though it still needs more assessment due to limited evidence.

Using PubMed as a major search resource, a thorough analysis of publications was carried out after incorporating this review's inclusion and exclusion criteria. A total of 455,141 publications were found using keywords and keyword combinations. With a careful selection of articles, 31 publications provided relevant information on our primary endpoint. All articles in this examination were chosen without limitation to the type of study, including clinical trials, review articles, meta-analyses, and so on. Our review suggests that, based on factors such as early detection and management, disease severity, ethnicity, and quality of patient care, patients with PPCM presented different outcomes and prognosis. However, despite PPCM's high mortality rate and its risk of recurrence, most patients tend to recover within six months of disease onset.

Did a shared thioredoxin-reductase gene mutation lead to maternal peripartum cardiomyopathy and fatal dilated cardiomyopathy in her son? A case report

Peripartum cardiomyopathy (PPCM) is characterized by development of left ventricular systolic dysfunction and heart failure that occurs towards the end of pregnancy or in the postpartum period in the absence of structural heart disease. A complex interplay of pathophysiological mechanisms likely contributes to the PPCM phenotype. Mutations in the mitochondrial thioredoxin reductase gene (TXNRD2) have been identified as a cause of dilated cardiomyopathy. We report a case of a shared, inherited genetic mutation in the TXNRD2 gene in a mother with PPCM and her infant son who died of dilated cardiomyopathy.

Peripartum Cardiomyopathy Incidence, Risk Factors, Diagnostic Criteria, Pathophysiology, and Treatment Options

Peripartum cardiomyopathy is a rare and a severe form of heart failure that affects women during pregnancy or shortly after delivery. Risk factors include advanced age, race, multiparity, multifetal pregnancy, socioeconomic disparity, and medical comorbidities including systemic hypertension, diabetes, asthma, and anemia. Peripartum cardiomyopathy is associated with increased morbidity and mortality, as well as a detrimental long-term impact on quality of life. Its etiology is not clear, although it is thought to be a combined effect of a hyperdynamic fluid state associated with pregnancy, hormonal changes unique to gestation, and a genetic predisposition. There is no current expert consensus on an optimal treatment regimen. This article will provide a comprehensive review and update on this important disease state.

Advances in the role and mechanism of BAG3 in dilated cardiomyopathy

The B cell lymphoma 2-associated anthanogene (BAG3) is an anti-apoptotic co-chaperone protein. Previous reports suggest that mutations in BAG3 are associated with dilated cardiomyopathy. This review aims to summarize the current understanding of the relationship between BAG3 mutations and dilated cardiomyopathy, primarily focusing on the role and protective mechanism of BAG3 in cardiomyocytes from individuals with dilated cardiomyopathy. The results of published studies show that BAG3 is critically important for reducing cardiomyocyte apoptosis, maintaining protein homeostasis, regulating mitochondrial stability, modulating myocardial contraction, and reducing cardiac arrhythmia, which suggests an indispensable protective mechanism of BAG3 in dilated cardiomyopathy. The significant role of BAG3 in protecting cardiomyocytes provides a new direction for the diagnosis and treatment of dilated cardiomyopathy. However, further research is required to explore the molecular mechanisms that regulate BAG3 expression, to identify a novel therapy for patients with dilated cardiomyopathy.

Peripartum cardiomyopathy: basic mechanisms and hope for new therapies

Peripartum cardiomyopathy (PPCM) is a life-threatening cardiomyopathy characterized by acute or slow progression of left ventricular (LV) systolic dysfunction (LV ejection fraction of &lt;45%) late in pregnancy, during delivery, or in the first postpartum months, in women with no other identifiable causes of heart failure. PPCM patients display variable phenotypes and risk factor profiles, pointing to involvement of multiple mechanisms in the pathogenesis of the disease. The higher risk for PPCM in women with African ancestry, the prevalence of gene variants associated with cardiomyopathies, and the high variability in onset and disease progression in PPCM patients also indicate multiple mechanisms at work. Experimental data have shown that different factors can induce and drive PPCM, including inflammation and immunity, pregnancy hormone impairment, catecholamine stress, defective cAMP-PKA, and G-protein-coupled-receptor signalling, and genetic variants. However, several of these mechanisms may merge into a common major pathway, which includes unbalanced oxidative stress and the cleavage of the nursing hormone prolactin (PRL) into an angiostatic, pro-apoptotic, and pro-inflammatory 16 kDa-PRL fragment, resulting in subsequent vascular damage and heart failure. Based on this common pathway, potential disease-specific biomarkers and therapies have emerged. Despite commonalities, the variation in aetiology and mechanisms poses challenges for the diagnosis, treatment, and management of the disease. This review summarizes current knowledge on the clinical presentation of PPCM in the context of recent experimental research. It discusses the challenge to develop disease-specific biomarkers in the context of rapid changing physiology in the peripartum phase, and outlines possible future treatment and management strategies for PPCM patients.

The Association between Hypertensive Disorders of Pregnancy and Peripartum Cardiomyopathy

Peripartum cardiomyopathy (PPCM) is a diagnosis of exclusion and a heterogeneous disorder that presents during the last month of pregnancy or the first five months postpartum. It is a rare but potentially life-threatening illness. A lot of work has been done trying to discover the causes of this condition, and several risk factors have been identified, including hypertension during pregnancy (HDP), ethnicity, advanced age, and multiple gestations. HDP affects 40% of cases of PPCM, and the strength of the association increases with increasing severity of hypertension. Among PPCM patients, there is a 1.5 times higher prevalence of HDP and a four-fold higher prevalence of preeclampsia (PE). Besides, the risk of PPCM markedly increases among women with HDP (5-21 times) compared with normotensive women. The experimental work done in animal models has provided support for the angiogenic-imbalance theory proposed regarding the association between these two conditions. The presence of the same risk factors also supports the prevalence of the coexistence of PE and PPCM. During the last part of gestation, the placenta secretes more anti-angiogenic factors, which leads to the development of both PE and PPCM. However, not all patients with HDP develop PPCM. In fact, most PPCM patients do not show any signs of HDP. Further work in these patients elucidated that there is an underlying susceptibility in some women that predisposes them to develop this condition and results in a worse prognosis as compared with those PPCM patients who have HDP. Better provision of care, genetic variations, and association with HDP have been cited as some of the factors affecting prognosis. HDP has also been found to increase the risk of other forms of cardiomyopathies in the future. A lot of work still needs to be done to uncover all the pathologic mechanisms and genetic variations involved in this disorder. More intensive and focussed research may help in developing new therapies to better manage this condition and address all of its complications. 

A novel LMNA nonsense mutation causes two distinct phenotypes of cardiomyopathy with high risk of sudden cardiac death in a large five-generation family

Aims

Characterization of the cardiac phenotype associated with the novel LMNA nonsense mutation c.544C>T, p.Q182*, which we have identified in a large five-generation family.

Methods and results

A family tree was constructed. Clinical data [arrhythmia, syncope, sudden cardiac death (SCD), New York Heart Association (NYHA) class] were collected from living and deceased family members. DNA of 23 living family members was analysed for mutations in LMNA. Additionally, dilated cardiomyopathy multi-gene-panel testing and whole exome sequencing were performed in some family members to identify potential phenotype-modifiers. In this five-generation family (n = 65), 17 SCDs occurred at 49.3 ± 10.0 years. Furthermore, we identified eight additional mutation-carriers, seven symptomatic (44 ± 13 years), and one asymptomatic (44 years). First signs of disease [sinus bradycardia with atrioventricular (AV)-block I°] occurred at 36.5 ± 8.1 years. Paroxysmal atrial fibrillation (AF) (onset at 41.8 ± 5.7 years) rapidly progressed to permanent AF (46.2 ± 9.8 years). Subsequently, AV-conduction worsened, syncope, pacemaker-dependence, and non-sustained ventricular tachycardia (43.3 ± 8.2 years) followed. Ventricular arrhythmia caused SCD in patients without implantable cardioverter-defibrillator (ICD). Patients protected by ICD developed rapidly progressive heart failure (45.2 ± 10.6 years). A different phenotype was seen in a sub-family in three patients with early onset of rapidly decompensating heart failure and only minor prior arrhythmia-related symptoms. One patient received high-urgency heart transplantation (HTX) at 32 years, while two died prior to HTX. One of them developed lethal peripartum-associated heart failure. Possible disease-modifiers were identified in this 'heart failure sub-family'.

Conclusion

The novel LMNA nonsense mutation c.544C>T causes a severe arrhythmogenic phenotype manifesting with high incidence of SCD in most patients; and in one sub-family, a distinct phenotype with fast progressing heart failure, indicating the need for early consideration of ICD-implantation and listing for heart-transplantation.

Electrocardiographic findings in peripartum cardiomyopathy

Background

There is limited data on electrocardiographic (ECG) abnormalities and their prognostic significance in women with peripartum cardiomyopathy (PPCM). We sought to characterize ECG findings in PPCM and explore the association of ECG findings with myocardial recovery and clinical outcomes.

Hypothesis

We hypothesized that ECG indicators of myocardial remodeling would portend worse systolic function and outcomes.

Methods

Standard 12‐lead ECGs were obtained at enrollment in the Investigations of Pregnancy‐Associated Cardiomyopathy study and analyzed for 88 women. Left ventricular ejection fraction (LVEF) was measured by echocardiography at baseline, 6 months, and 12 months. Women were followed for clinical events (death, mechanical circulatory support, and/or cardiac transplantation) until 1 year.

Results

Half of women had an “abnormal” ECG, defined as atrial abnormality, ventricular hypertrophy, ST‐segment deviation, and/or bundle branch block. Women with left atrial abnormality (LAA) had lower LVEF at 6 months (44% vs 52%, P = 0.02) and 12 months (46% vs 54%, P = 0.03). LAA also predicted decreased event‐free survival at 1 year (76% vs 97%, P = 0.008). Neither left ventricular hypertrophy by ECG nor T‐wave abnormalities predicted outcomes. A normal ECG was associated with recovery in LVEF to ≥50% (84% vs 49%, P = 0.001) and event‐free survival at 1 year (100% vs 85%, P = 0.01).

Conclusions

ECG abnormalities are common in women with PPCM, but a normal ECG does not rule out the presence of PPCM. LAA predicted lower likelihood of myocardial recovery and event‐free survival, and a normal ECG predicted favorable event‐free survival.

Peripartum cardiomyopathy

Peripartum cardiomyopathy (PPCM) is a rare, often dilated, cardiomyopathy with systolic dysfunction that presents in late pregnancy or, more commonly, the early postpartum period. Although the condition is prevalent worldwide, women with black ancestry seem to be at greatest risk, and the condition has a particularly high incidence in Nigeria and Haiti. Other risk factors include pre-eclampsia, advanced maternal age, and multiple gestation pregnancy. Although the complete pathophysiology of peripartum cardiomyopathy remains unclear, research over the past decade suggests the importance of vasculo-hormonal pathways in women with underlying susceptibility. At least some women with the condition harbor an underlying sarcomere gene mutation. More than half of affected women recover systolic function, although some are left with a chronic cardiomyopathy, and a minority requires mechanical support or cardiac transplantation (or both). Other potential complications include thromboembolism and arrhythmia. Currently, management entails standard treatments for heart failure with reduced ejection fraction, with attention to minimizing potential adverse effects on the fetus in women who are still pregnant. Bromocriptine is one potential disease specific treatment under investigation. In this review, we summarize the current literature on peripartum cardiomyopathy, as well as gaps in the understanding of this condition and future research directions.