Molecular mechanisms of peripartum cardiomyopathy: A vascular/hormonal hypothesis

Disease features and management of cardiomyopathies in women

Over the last years, there has been a growing interest in the clinical manifestations and outcomes of cardiomyopathies in women. Peripartum cardiomyopathy is the only women-specific cardiomyopathy. In cardiomyopathies with X-linked transmission, women are not simply healthy carriers of the disorder, but can show a wide spectrum of clinical manifestations ranging from mild to severe manifestations because of heterogeneous patterns of X-chromosome inactivation. In mitochondrial disorders with a matrilinear transmission, cardiomyopathy is part of a systemic disorder affecting both men and women. Even some inherited cardiomyopathies with autosomal transmission display phenotypic and prognostic differences between men and women. Notably, female hormones seem to exert a protective role in hypertrophic cardiomyopathy (HCM) and variant transthyretin amyloidosis until the menopausal period. Women with cardiomyopathies holding high-risk features should be referred to a third-level center and evaluated on an individual basis. Cardiomyopathies can have a detrimental impact on pregnancy and childbirth because of the associated hemodynamic derangements. Genetic counselling and a tailored cardiological evaluation are essential to evaluate the likelihood of transmitting the disease to the children and the possibility of a prenatal or early post-natal diagnosis, as well as to estimate the risk associated with pregnancy and delivery, and the optimal management strategies.

Guyton perspective in managing peripartum cardiomyopathy patient with pulmonary edema: a case report

BACKGROUND

Peripartum cardiomyopathy (PPCM) is a potentially life-threatening pregnancy-related condition characterized by left ventricular dysfunction and heart failure, typically occurring in the peripartum period. Individuals with a history of preeclampsia and hypertension are particularly prone to developing PPCM. Recent research suggests that the condition may be triggered by vascular dysfunction influenced by maternal hormones in the late stages of gestation. The onset of left heart failure results in decreased cardiac output, leading to insufficient perfusion, which in turn, contributes to pulmonary edema and exacerbates tissue hypoxia. This cardiovascular response activates the neurohumoral system, causing peripheral vasoconstriction and elevating both mean capillary filling pressure (MCFP) and central venous pressure (CVP). Early administration of furosemide reduces volume overload due to negative cumulative fluid balance gaining and vasodilation, which increases the velocity of intravascular refilling and causes interstitial edema to resolve. This will decrease interstitial fluid pressure, resulting in decreased mechanical compression to systemic capillary and systemic vein pressure, thus decreasing MCFP and CVP subsequently. Reduced CVP also contributes to increased venous return by decreasing the gradient pressure between MCFP and CVP, resulting in increased cardiac output (CO) and improved tissue oxygenation.

CASE

A 33-year-old Asian woman, para 3 at full term pregnancy, admitted to the intensive care unit (ICU) after c-section and tubectomy due to shortness of breath and palpitation. Based on history taking, physical examination and echocardiography the patient fulfilled the criteria of PPCM which was also complicated by pulmonary edema. Despite impending respiratory failure, the patient rejected intubation and continuous positive airway pressure (CPAP), and was given oxygen supplementation through nasal cannula. Furosemide was given rapidly continued by maintenance dose and CVP was monitored. Antihypertensive drug, anticoagulants, and bromocriptine were also administered. After achieving negative cumulative fluid balance the patient's symptoms resolved and was discharged one week later.

CONCLUSION

There is a correlation between negative cumulative fluid balance and reduced central venous pressure after early furosemide therapy. Suspicion for PPCM should not be lowered in the presence of preeclampsia, it could delay appropriate treatment and increase the mortality.

Clinical predictors of right ventricular dysfunction and association with adverse outcomes in peripartum cardiomyopathy

AIMS

We sought to identify factors associated with right ventricular (RV) dysfunction and elevated pulmonary artery systolic pressure (PASP) and association with adverse outcomes in peripartum cardiomyopathy (PPCM).

METHODS AND RESULTS

We conducted a multi-centre cohort study to identify subjects with PPCM with the following criteria: left ventricular ejection fraction (LVEF) < 40%, development of heart failure within the last month of pregnancy or 5 months of delivery, and no other identifiable cause of heart failure with reduced ejection fraction. Outcomes included a composite of (i) major adverse events (need for extracorporeal membrane oxygenation, ventricular assist device, orthotopic heart transplantation, or death) or (ii) recurrent heart failure hospitalization. RV function was obtained from echocardiogram reports. In total, 229 women (1993-2017) met criteria for PPCM. Mean age was 32.4 ± 6.8 years, 28% were of African descent, 50 (22%) had RV dysfunction, and 38 (17%) had PASP ≥ 30 mmHg. After a median follow-up of 3.4 years (interquartile range 1.0-8.8), 58 (25%) experienced the composite outcome of adverse events. African descent, family history of cardiomyopathy, LVEF, and PASP were significant predictors of RV dysfunction. Using Cox proportional hazards models, we found that women with RV dysfunction were three times more likely to experience the adverse composite outcome: hazard ratio 3.21 (95% confidence interval: 1.11-9.28), P = 0.03, in a multivariable model adjusting for age, race, body mass index, preeclampsia, hypertension, diabetes, kidney disease, and LVEF. Women with PASP ≥ 30 mmHg had a lower probability of survival free from adverse events (log-rank P = 0.04).

CONCLUSIONS

African descent and family history of cardiomyopathy were significant predictors of RV dysfunction. RV dysfunction and elevated PASP were significantly associated with a composite of major adverse cardiac events. This at-risk group may prompt closer monitoring or early referral for advanced therapies.

Cardiogenic shock in pregnancy

Cardiac disease complicates 1%-4% of pregnancies globally, with a predominance in low and middle-income countries (LMICs). Increasing maternal age, rates of obesity, cardiovascular comorbidities, pre-eclampsia and gestational diabetes all contribute to acquired cardiovascular disease in pregnancy. Additionally, improved survival in congenital heart disease (CHD) has led to increasing numbers of women with CHD undergoing pregnancy. Implementation of individualised care plans formulated through pre-conception counselling and based on national and international guidance have contributed to improved clinical outcomes. However, there remains a significant proportion of women of reproductive age with no apparent comorbidities or risk factors that develop heart disease during pregnancy, with no indication for pre-conception counselling. The most extreme manifestation of cardiac disease is cardiogenic shock (CS), where the primary cardiac pathology results in inadequate cardiac output and hypoperfusion, and is associated with significant mortality and morbidity. Key to management is early recognition, intervention to treat any potentially reversible underlying pathology and supportive measures, up to and including mechanical circulatory support (MCS). In this narrative review we discuss recent developments in the classification of CS, and how these may be adapted to improve outcomes of pregnant women with, or at risk of developing, this potentially lethal condition.

Serum Proteomic Analysis of Peripartum Cardiomyopathy Reveals Distinctive Dysregulation of Inflammatory and Cholesterol Metabolism Pathways

BACKGROUND

The pathophysiology of peripartum cardiomyopathy (PPCM) and its distinctive biological features remain incompletely understood. High-throughput serum proteomic profiling, a powerful tool to gain insights into the pathophysiology of diseases at a systems biology level, has never been used to investigate PPCM relative to nonischemic cardiomyopathy.

OBJECTIVES

The aim of this study was to characterize the pathophysiology of PPCM through serum proteomic analysis.

METHODS

Aptamer-based proteomic analysis (SomaScan 7K) was performed on serum samples from women with PPCM (n = 67), women with nonischemic nonperipartum cardiomyopathy (NPCM) (n = 31), and age-matched healthy peripartum and nonperipartum women (n = 10 each). Serum samples were obtained from the IPAC (Investigation of Pregnancy-Associated Cardiomyopathy) and IMAC2 (Intervention in Myocarditis and Acute Cardiomyopathy) studies.

RESULTS

Principal component analysis revealed unique clustering of each patient group (P for difference <0.001). Biological pathway analyses of differentially measured proteins in PPCM relative to NPCM, before and after normalization to pertinent healthy controls, highlighted specific dysregulation of inflammatory pathways in PPCM, including the upregulation of the cholesterol metabolism-related anti-inflammatory pathway liver-X receptor/retinoid-X receptor (LXR/RXR) (P < 0.01, Z-score 1.9-2.1). Cardiac recovery by 12 months in PPCM was associated with the downregulation of pro-inflammatory pathways and the upregulation of LXR/RXR, and an additional RXR-dependent pathway involved in the regulation of inflammation and metabolism, peroxisome proliferator-activated receptor α/RXRα signaling.

CONCLUSIONS

Serum proteomic profiling of PPCM relative to NPCM and healthy controls indicated that PPCM is a distinct disease entity characterized by the unique dysregulation of inflammation-related pathways and cholesterol metabolism-related anti-inflammatory pathways. These findings provide insight into the pathophysiology of PPCM and point to novel potential therapeutic targets.

Long-Term Outcomes of Women With Peripartum Cardiomyopathy Having Subsequent Pregnancies

BACKGROUND

Long-term maternal outcomes of subsequent pregnancies (SSPs) in patients with peripartum cardiomyopathy (PPCM) have not been analyzed.

OBJECTIVES

The goal of this study was to evaluate the long-term survival of SSPs in women with PPCM.

METHODS

We conducted a retrospective review of 137 PPCMs in the registry. The clinical and echocardiographic findings were compared between the recovery group (RG) and nonrecovery group (NRG), defined as left ventricular ejection fraction ≥50% and <50% after an index of pregnancy, respectively.

RESULTS

Forty-five patients with SSPs were included with a mean age of 27.0 ± 6.1 years, 80% were of African American descent, and 75.6% from a low socioeconomic background. Thirty (66.7%) women were in the RG. Overall, SSPs were associated with a decrease in mean left ventricular ejection fraction from 45.1% ± 13.7% to 41.2% ± 14.5% (P = 0.009). At 5 years, adverse outcomes were significantly higher in the NRG compared with the RG (53.3% vs 20%; P = 0.04), driven by relapse PPCM (53.3% vs 20.0%; P = 0.03). Five-year all-cause mortality was 13.33% in the NRG compared with 3.33% in the RG (P = 0.25). At a median follow-up of 8 years, adverse outcomes and all-cause mortality rates were similar in the NRG and RG (53.3% vs 33.3% [P = 0.20] and 20% vs 20%, respectively).

CONCLUSIONS

Subsequent pregnancies in women with PPCM are associated with adverse events. The normalization of left ventricular function does not guarantee a favorable outcome in the SSPs.

Arrhythmias and Heart Failure in Pregnancy: A Dialogue on Multidisciplinary Collaboration

The prevalence of CVD in pregnant people is estimated to be around 1 to 4%, and it is imperative that clinicians that care for obstetric patients can promptly and accurately diagnose and manage common cardiovascular conditions as well as understand when to promptly refer to a high-risk obstetrics team for a multidisciplinary approach for managing more complex patients. In pregnant patients with CVD, arrhythmias and heart failure (HF) are the most common complications that arise. The difficulty in the management of these patients arises from variable degrees of severity of both arrhythmia and heart failure presentation. For example, arrhythmia-based complications in pregnancy can range from isolated premature ventricular contractions to life-threatening arrhythmias such as sustained ventricular tachycardia. HF also has variable manifestations in pregnant patients ranging from mild left ventricular impairment to patients with advanced heart failure with acute decompensated HF. In high-risk patients, a collaboration between the general obstetrics, maternal-fetal medicine, and cardiovascular teams (which may include cardio-obstetrics, electrophysiology, adult congenital, or advanced HF)—physicians, nurses and allied professionals—can provide the multidisciplinary approach necessary to properly risk-stratify these women and provide appropriate management to improve outcomes.

NT-proBNP and predictors of event free survival and left ventricular systolic function recovery in peripartum cardiomyopathy

OBJECTIVE

To determine predictors of adverse outcomes in peripartum cardiomyopathy (PPCM).

METHODS AND RESULTS

We conducted a multi-center cohort study across four centers to identify subjects with PPCM with the following criteria: LVEF <40%, development of heart failure within the last month of pregnancy or within 5 months of delivery and no other identifiable cause of heart failure with reduced ejection fraction. Outcomes included 1) survival free from major adverse events (need for extra-corporeal membrane oxygenation, ventricular assist device, orthotopic heart transplantation or death) and 2) LVEF recovery ≥ 50%. Using a univariate logistic regression analysis, we identified significant clinical predictors of these outcomes, which were then used to create multivariable models. NT-proBNP at the time of diagnosis was examined both as a continuous variable (log transformed) in logistic regression and as a dichotomous variable (values above and below the median) using the log-rank test. In all, 237 women (1993 to 2017) with 736.4 person-years of follow-up, met criteria for PPCM. Participants had a mean age of 32.4 ± 6.7 years, mean BMI 30.6 ± 7.8 kg/m2; 63% were White. After median follow-up of 3.6 years (IQR 1.1-7.8), 113 (67%) had LVEF recovery, and 222 (94%) had survival free from adverse events. Significant predictors included gestational age, gravidity, systolic blood pressure, smoking, heart rate, initial LVEF, and diuretic use. In a subset of 110 patients with measured NTproBNP levels, we found a higher event free survival for women with NTproBNP <2585 pg/ml (median) as compared to women with NTproBNP ≥2585 pg/ml (log-rank test p-value 0.018).

CONCLUSION

Gestational age, gravidity, current or past tobacco use, systolic blood pressure, heart rate, initial LVEF and diuretic requirement at the time of diagnosis were associated with survival free from adverse events and LVEF recovery. Initial NT-proBNP was significantly associated with event free survival.

Animal Models of Cardiovascular Complications of Pregnancy

Cardiovascular complications of pregnancy have risen substantially over the past decades, and now account for the majority of pregnancy-induced maternal deaths, as well as having substantial long-term consequences on maternal cardiovascular health. The causes and pathophysiology of these complications remain poorly understood, and therapeutic options are limited. Preclinical models represent a crucial tool for understanding human disease. We review here advances made in preclinical models of cardiovascular complications of pregnancy, including preeclampsia and peripartum cardiomyopathy, with a focus on pathological mechanisms elicited by the models and on relevance to human disease.

Risk factors and outcomes associated with Left Ventricular Thrombus in patients with Peripartum Cardiomyopathy: An insight from National Inpatient Sample Database

Background

: We sought to assess the prevalence and impact of left ventricular thrombus (LVT) in patients with peripartum cardiomyopathy (PPCM).

Methods

: We performed a retrospective cohort study of all admissions with PPCM as the primary diagnosis from the Nationwide Inpatient Sample database over a 11-year period. Univariate analysis of all risk factors and outcomes and multivariable logistic regression analysis of certain variables were performed and represented as odds ratio (OR) with 95% confidence interval (CI). A p value of < 0.05 was considered statistically significant. Statistical analysis was performed using epiDisplay in ‘R’ studio.

Results

: In the time frame spanning 2005 -2014, 43,986 admissions with PPCM were found which included 43,534 without LVT and 452 patients with LVT. Black race was associated with a higher incidence of LV thrombus, (p value <0.001). Comorbidities more prevalent in the LVT group were smoking, drug abuse, pregnancy induced hypertension, diabetes with complications, valvular heart disease, connective tissue disorders, coagulopathy, anemia and depression. Adverse outcomes such as congestive heart failure, arrhythmias and stroke were higher in LVT group. Conversely, Caucasian race, obesity, preeclampsia (p <0.005) were higher in those without LVT. Mean length of stay (9 vs 5 days, p <0.001), in hospital mortality (3.32% vs 1.41%, p = 0.001) and mean hospitalization charges ($85,390 vs $48,033) were higher in those with LVT. However, on multivariate logistic regression, although stroke was higher in the LVT group (adjusted OR 5.51, 95% CI, 2.2, 13.81, 5.05, p 0.002), in-hospital mortality was not significantly different between the two groups (adjusted OR 1.17, 95% CI,0.32, 4.23, p = 0.817).

Conclusion

: Our study showed that PPCM patients with LV thrombus had worse outcomes with respect to stroke, length of stay and in hospital mortality. Higher prevalence in patients with black race, complicated diabetes, peripheral vascular disease, valvular disease, coagulopathy, smoking, drug abuse, depression and psychoses calls for special attention to such high-risk groups for aggressive risk factor modification.

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.

Peripartum cardiomyopathy: a global effort to find the cause and cure for the rare and little understood disease

In this review, we present our current understanding of peripartum cardiomyopathy (PPCM) based on reports of the incidence, diagnosis and current treatment options. We summarise opinions on whether PPCM is triggered by vascular and/or hormonal causes and examine the influence of comorbidities such as preeclampsia. Two articles published in 2021 strongly support the hypothesis that PPCM may be a familial disease. Using large cohorts of PPCM patients, they summarised the available genomic DNA sequence data that are expressed in human cardiomyocytes. While PPCM is considered a disease predominately affecting the left ventricle, there are data to suggest that some cases also involve right ventricular failure. Finally, we conclude that there is sufficient evidence to warrant an RNAseq investigation and that this would be most informative if performed at the cardiomyocytes level rather than analysing genomic DNA from the peripheral circulation. Given the rarity of PPCM, the combined resources of international human heart tissue biobanks have assembled 30 ventricular tissue samples from PPCM patients, and we are actively seeking to enlarge this patient base by collaborating with human heart tissue banks and research laboratories who would like to join this endeavour.

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.

[Peripartum cardiomyopathy: A review of the literature]

Peripartum cardiomyopathy is a rare and unpredictable pregnancy-related pathology. Idiopathic cardiomyopathy is characterized by a heart failure secondary to left ventricular systolic dysfunction appearing towards the end of pregnancy or in the months following delivery with a non-specific clinic presentation. Through reviewing previous research, our critical literature review wishes to bring a concise and objective summarize for a better understanding of physiopathology, evocative symptoms and knowing of factors influencing prognosis in order to standardize peripartum management. The treatment remains mainly symptomatic but other promising treatments are still in development. In conclusion, early detection and treatment allow a better cardiac function recovery reducing cardiac transplantation.

A Systematic Review of the Utility of Bromocriptine in Acute Peripartum Cardiomyopathy

In formerly healthy females, acute heart failure (HF) of an unknown cause that develops during the last weeks of gestation or in the first months after childbirth is known as peripartum cardiomyopathy (PPCM). This study aimed to establish the therapeutic value of combining bromocriptine with conventional HF treatment on left ventricular ejection fraction (LVEF), death, thromboembolic events, left ventricular (LV) dysfunction recurrence in subsequent pregnancies in PPCM women, and newborn children's outcomes. We conducted a systematic review to find clinical studies that described the utility of bromocriptine in addition to conventional HF treatment compared to conventional HF treatment only in the management of acute PPCM. Four databases comprising records from July 10, 2001, to July 10, 2021, were analyzed, including PubMed (MEDLINE), Google Scholar, Scopus, and the Cochrane Library. We discovered 4,717 potentially eligible records across all the databases. According to our eligibility criteria, we included six studies consisting of 263 patients in this review. Bromocriptine combined with conventional HF therapy led to an 11.37% increase in LVEF (mean difference: 11.37; 95% confidence interval [CI]: 9.55-13.19; p-value = 0.001) after six months compared to conventional HF treatment only. Notably, bromocriptine combined with conventional HF treatment reduced mortality associated with PPCM, and no thromboembolism events were recorded in the 263 patients. PPCM is a severe condition affecting women globally. In this study, the combination of bromocriptine with conventional HF treatment enhanced the LVEF of women with acute PPCM and their clinical outcomes.

Peripartum Cardiomyopathy

Peripartum cardiomyopathy (PPCM) is a form of heart failure that occurs toward the end of pregnancy or in the months following pregnancy and is marked by left ventricular systolic dysfunction. The cause of PPCM remains unknown and there is no diagnostic test specific to PPCM. Outcomes vary and include complete left ventricular recovery, persistent cardiac dysfunction, transplant, and death. Numerous advances have been made in understanding this disease, but many knowledge gaps remain. This article reviews recent data and recommendations for clinical practice in addition to highlighting the multiple knowledge gaps related to PPCM that warrant further investigation.

Genetic and Phenotypic Landscape of Peripartum Cardiomyopathy

BACKGROUND

Peripartum cardiomyopathy (PPCM) occurs in ≈1:2000 deliveries in the United States and worldwide. The genetic underpinnings of PPCM remain poorly defined. Approximately 10% of women with PPCM harbor truncating variants in TTN (TTNtvs). Whether mutations in other genes can predispose to PPCM is not known. It is also not known if the presence of TTNtvs predicts clinical presentation or outcomes. Nor is it known if the prevalence of TTNtvs differs in women with PPCM and preeclampsia, the strongest risk factor for PPCM.

METHODS

Women with PPCM were retrospectively identified from several US and international academic centers, and clinical information and DNA samples were acquired. Next-generation sequencing was performed on 67 genes, including TTN, and evaluated for burden of truncating and missense variants. The impact of TTNtvs on the severity of clinical presentation, and on clinical outcomes, was evaluated.

RESULTS

Four hundred sixty-nine women met inclusion criteria. Of the women with PPCM, 10.4% bore TTNtvs (odds ratio=9.4 compared with 1.2% in the reference population; Bonferroni-corrected P [P*]=1.2×10-46). We additionally identified overrepresentation of truncating variants in FLNC (odds ratio=24.8, P*=7.0×10-8), DSP (odds ratio=14.9, P*=1.0×10-8), and BAG3 (odds ratio=53.1, P*=0.02), genes not previously associated with PPCM. This profile is highly similar to that found in nonischemic dilated cardiomyopathy. Women with TTNtvs had lower left ventricular ejection fraction on presentation than did women without TTNtvs (23.5% versus 29%, P=2.5×10-4), but did not differ significantly in timing of presentation after delivery, in prevalence of preeclampsia, or in rates of clinical recovery.

CONCLUSIONS

This study provides the first extensive genetic and phenotypic landscape of PPCM and demonstrates that predisposition to heart failure is an important risk factor for PPCM. The work reveals a degree of genetic similarity between PPCM and dilated cardiomyopathy, suggesting that gene-specific therapeutic approaches being developed for dilated cardiomyopathy may also apply to PPCM, and that approaches to genetic testing in PPCM should mirror those taken in dilated cardiomyopathy. Last, the clarification of genotype/phenotype associations has important implications for genetic counseling.

Peripartum cardiomyopathy

Peripartum cardiomyopathy is now increasingly recognized as a cause of heart failure in the later months of pregnancy and early postpartum period. Clinical diagnosis may be challenging as it closely resembles several common medical and obstetric complications. Complex pathogenesis, unpredictable onset, staggered recovery, and unanticipated fetomaternal risks pose unique challenge to clinicians. Prevalence seems to vary with race, geographic location, and diagnostic criteria. The presence of multiple risk factors substantially elevates the risk of PPCM. Transthoracic echocardiographic examination can exclude the majority of the mimickers. Symptomatic presentation is initially limited to, varying grades of low cardiac output syndrome. Rarely, PPCM begins with decompensated heart failure and cardiovascular collapse. Guideline-directed medical therapy involves graded initiation and titration of heart failure medications while ensuring the fetal and neonatal safety. Anesthetic and obstetric management should be individualized to improve fetomaternal outcomes. However, emergent cesarean delivery may be required in women with decompensated heart failure and cardiovascular collapse. An early institution of mechanical circulatory support has shown to improve outcome. Bromocriptine and other experimental drugs designed to target pathogenic pathway have yielded mixed results. A further change in approach to management requires a comprehensive understanding of pathophysiology and fetomaternal safety profiles of heart failure medications.

Biomarkers and Their Relation to Cardiac Function Late After Peripartum Cardiomyopathy

BACKGROUND

Angiogenic imbalance involving the placental protein soluble Fms-like tyrosine kinase-1 (sFlt-1) and cleavage of the nursing-hormone prolactin by the enzyme cathepsin D (CD) both play a role in the pathogenesis of peripartum cardiomyopathy (PPCM). We hypothesized that angiogenic imbalance and increased activity of CD have a long-lasting impact in women with PPCM.

METHODS AND RESULTS

A nationwide Danish cohort of women with PPCM (PPCM group, n = 28), age matched women with previous preeclampsia (n = 28) and uncomplicated pregnancies (n = 28) participated in a follow-up study including biomarker analysis, exercise testing and cardiac magnetic resonance imaging. The median time to follow-up was 91 months (range 27-137 months) for the PPCM group. Levels of sFlt-1, placental growth factor, N-terminal pro-natriuretic brain peptide, and copeptin were all significantly higher in the PPCM group. More women in the PPCM group had detectable CD activity (68%) compared with the preeclampsia group (29%) and uncomplicated pregnancies group (36%) (P = .0002). Levels of angiogenic factors and biomarkers correlated inversely with maximal exercise capacity and cardiac functional parameters assessed with cardiac magnetic resonance imaging.

CONCLUSIONS

Women with PPCM had higher biomarker levels and CD activity up to 7 years after diagnosis. Higher biomarker levels correlated inversely with maximal exercise capacity and markers of cardiac dysfunction suggesting that persistent angiogenic imbalance and increased CD activity is associated with residual cardiac dysfunction.

A Case-Control Study of Peripartum Cardiomyopathy Using the Rochester Epidemiology Project

Background:

The incidence of peripartum cardiomyopathy (PPCM) is known through referral center databases that may be affected by referral, misclassification, and other biases. We sought to determine the community-based incidence and natural history of PPCM using the Rochester Epidemiology Project.

Methods and Results:

Incident cases of PPCM occurring between January 1, 1970, and December 31, 2014, were identified in Olmsted County, Minnesota. A total of 15 PPCM cases were confirmed yielding an incidence of 20.3 cases per 100,000 live births in Olmsted County, Minnesota. Clinical information, disease characteristics, and outcomes were extracted from medical records in a 27-county region of the Rochester Epidemiology Project including Olmsted County and matched in a 1:2 ratio with pregnant women without PPCM. A total of 48 women were identified with PPCM in the expanded 27-county region. There was 1 death and no transplants over a median of 7.3 years of follow-up. Six of the 23 women with subsequent pregnancies developed recurrent PPCM, all of whom recovered. Migraine and anxiety were identified as novel possible risk factors for PPCM.

Conclusions:

The population-based incidence of PPCM was 20.3 cases per 100,000 live births in Olmsted County, Minnesota. Cardiovascular outcomes were generally excellent in this community cohort.

Comparison of Clinical Characteristics and Outcomes of Peripartum Cardiomyopathy Between African American and Non-African American Women

Importance

Peripartum cardiomyopathy (PPCM) disproportionately affects women of African ancestry, but well-powered studies to explore differences in severity of disease and clinical outcomes are lacking.

Objective

To compare the clinical characteristics, presentation, and outcomes of PPCM between African American and non-African American women.

Design, Setting, and Participants

This retrospective cohort study using data from January 1, 1986, through December 31, 2016, performed at the University of Pennsylvania Health System, a tertiary referral center serving a population with a high proportion of African American individuals, included 220 women with PPCM.

Main Outcomes and Measures

Demographic and clinical characteristics and echocardiographic findings at presentation, as well as clinical outcomes including cardiac recovery, time to recovery, cardiac transplant, persistent dysfunction, and death, were compared between African American and non-African American women with PPCM.

Results

A total of 220 women were studied (mean [SD] age at diagnosis, 29.5 [6.6] years). African American women were diagnosed with PPCM at a younger age (27.6 vs 31.7 years, P < .001), were diagnosed with PPCM later in the postpartum period, and were more likely to present with a left ventricular ejection fraction less than 30% compared with non-African American women (48 [56.5%] vs 30 [39.5%], P = .03). African American women were also more likely to worsen after initial diagnosis (30 [35.3%] vs 14 [18.4%], P = .02), were twice as likely to fail to recover (52 [43.0%] vs 24 [24.2%], P = .004), and, when they did recover, recovery took at least twice as long (median, 265 vs 125.5 days; P = .02) despite apparent adequate treatment.

Conclusions and Relevance

In a large cohort of women with well-phenotyped PPCM, this study demonstrates a different profile of disease in African American vs non-African American women. Further work is needed to understand to what extent these differences stem from genetic or socioeconomic differences and how treatment of African American patients might be tailored to improve health outcomes.

Acute blood pressure elevation associated with biological therapies for cancer: a focus on VEGF signaling pathway inhibitors

INTRODUCTION

Treatment with biological agents interfering with mechanisms of angiogenesis, such as vascular endothelial growth factor (VEGF) signaling pathway (VSP) inhibitors, was associated with an enhanced risk of acute and severe blood pressure (BP) increase and development of hypertensive emergencies. Areas covered: The present article will review the scientific literature reporting hypertensive emergencies as a complication of biological treatment with VSP inhibitors. Hypertensive emergency is a life-threatening condition characterized by very high BP values (>180/110 mmHg) associated with acute organ damage. The exact mechanism of action is still incompletely clarified. Endothelial dysfunction following reduced bioavailability of nitric oxide has been hypothesized to play an important role in promoting hypertension and the occurrence of acute organ damage. Expert opinion: Prevention, prompt recognition and treatment of hypertensive emergencies associated with treatment with VSP-inhibitors are essential to reduce the risk of adverse events. Not infrequently, the occurrence of hypertensive emergency led to VSP treatment discontinuation, with potential negative consequences on patient overall survival. The present review aims at providing detailed knowledge for the clinician regarding this specific issue, which could be of high impact in usual clinical practice, given the increasing burden of indications to treatment with biological agents targeted to the VEGF pathway.

Peripartum cardiomyopathy: disease or syndrome?

Peripartum cardiomyopathy (PPCM) is a rare form of pregnancy-associated heart failure and is considered to be a diagnosis of exclusion. There are many hypotheses on the aetiology of PPCM; however, the exact pathophysiological mechanism remains unknown. It shows many resemblances to other conditions, such as familial dilated cardiomyopathy or myocarditis, and therefore it can be hard to make a definite diagnosis. We describe four cases of peripartum-onset heart failure in women who were suspected of having PPCM. We discuss the differential diagnosis, pathophysiological mechanisms and various diagnostic modalities.

Placenta accreta complicated with peripartum cardiomyopathy

A 33-year-old G2P1 was referred to our hospital due to placenta accreta. During perioperative preparations, the patient was diagnosed with having a peripartum cardiomyopathy. The patient underwent caesarean hysterectomy at 36 weeks with an associated 2 L blood loss. Haemodynamic maintenance and stabilisation during the operation were challenging, with the combinations of fluid therapy, blood transfusions as well as vasoactive, antifibrinolytic and haemostatic drug. Postoperatively, the patient was managed in the intensive care unit and was subsequently transferred to intermediate care after less than 24 hours' observation. She was stable enough to be moved to the obstetrics ward the next day.

PDK4 Inhibits Cardiac Pyruvate Oxidation in Late Pregnancy

RATIONALE

Pregnancy profoundly alters maternal physiology. The heart hypertrophies during pregnancy, but its metabolic adaptations, are not well understood.

OBJECTIVE

To determine the mechanisms underlying cardiac substrate use during pregnancy.

METHODS AND RESULTS

We use here ¹³C glucose, ¹³C lactate, and ¹³C fatty acid tracing analyses to show that hearts in late pregnant mice increase fatty acid uptake and oxidation into the tricarboxylic acid cycle, while reducing glucose and lactate oxidation. Mitochondrial quantity, morphology, and function do not seem altered. Insulin signaling seems intact, and the abundance and localization of the major fatty acid and glucose transporters, CD36 (cluster of differentiation 36) and GLUT4 (glucose transporter type 4), are also unchanged. Rather, we find that the pregnancy hormone progesterone induces PDK4 (pyruvate dehydrogenase kinase 4) in cardiomyocytes and that elevated PDK4 levels in late pregnancy lead to inhibition of PDH (pyruvate dehydrogenase) and pyruvate flux into the tricarboxylic acid cycle. Blocking PDK4 reverses the metabolic changes seen in hearts in late pregnancy.

CONCLUSIONS

Taken together, these data indicate that the hormonal environment of late pregnancy promotes metabolic remodeling in the heart at the level of PDH, rather than at the level of insulin signaling.

Impact of Preeclampsia on Clinical and Functional Outcomes in Women With Peripartum Cardiomyopathy

BACKGROUND

Preeclampsia is a risk factor for the development of peripartum cardiomyopathy (PPCM), but it is unknown whether preeclampsia impacts clinical or left ventricular (LV) functional outcomes. This study sought to assess clinical and functional outcomes in women with PPCM complicated by preeclampsia.

METHODS AND RESULTS

This retrospective cohort study included women diagnosed with PPCM delivering at Barnes-Jewish Hospital between 2004 to 2014. The primary outcome was one-year event-free survival rate for the combined end point of death and hospital readmission. The secondary outcome was recovery of LV ejection fraction. Seventeen of 39 women (44%) with PPCM had preeclampsia. The groups had similar mean LV ejection fraction at diagnosis (29.6 with versus 27.3 without preeclampsia; P=0.5). Women with preeclampsia had smaller mean LV end-diastolic diameters (5.2 versus 6.0 cm; P=0.001), greater relative wall thickness (0.41 versus 0.35 mm Hg; P=0.009), and lower incidence of eccentric remodeling (12% versus 48%; P=0.03). Clinical follow-up was available for 32 women; 5 died of cardiovascular complications within 1 year of diagnosis (4/15 with versus 1/17 without preeclampsia; P=0.16). In time to event analysis, patients with preeclampsia had worse event-free survival during 1-year follow-up (P=0.047). Echocardiographic follow-up was available in 10 survivors with and 16 without preeclampsia. LV ejection fraction recovered in 80% of survivors with versus 25% without preeclampsia (P=0.014).

CONCLUSIONS

PPCM with concomitant preeclampsia is associated with increased morbidity and mortality and different patterns of LV remodeling and recovery of LV function when compared with patients with PPCM that is not complicated by preeclampsia.

Peripartum cardiomyopathy in Denmark: a retrospective, population-based study of incidence, management and outcome

AIM

Population-based European studies of peripartum cardiomyopathy (PPCM) are few. We aimed to estimate the nationwide incidence and outcome of PPCM in Denmark during 2005-2014.

METHODS AND RESULTS

The Danish National Birth Register and the Danish National Patient Register were linked and searched for cardiomyopathy and heart failure ICD-10 diagnoses in a period of nine months before to 12 months after a delivery from 1 January 2005 through 31 December 2014. Diagnoses were validated and additional data were extracted from patient charts. A total of 61 women met the inclusion criteria equalling 1 in 10 149 deliveries. The majority recovered left ventricular systolic function within one year, but 14.8% suffered a major adverse event with 3.3% mortality, 8.2% mechanical circulatory support requirement and/or heart transplantation and 4.9% persistent severe heart failure. Half of the women had a concomitant hypertensive disorder of pregnancy, and this subgroup had a milder course of the disease. Baseline left ventricular ejection fraction (LVEF) was the only significant predictor of LVEF 10-14 months after diagnosis, and cabergoline therapy to inhibit lactation predicted the dichotomous outcome of complete recovery (LVEF ≥55%).

CONCLUSION

The first validated, population-based European estimate of PPCM incidence is 1 in 10 149 deliveries, which places Denmark between American and Japanese estimates. Clinical outcome in the cohort was similar to those reported in recent cohorts. Women with concomitant hypertensive disorder of pregnancy had a milder course of PPCM. Baseline LVEF predicted LVEF 10-14 months after diagnosis and cabergoline predicted complete recovery.

Peripartum cardiomyopathy: a systematic literature review

INTRODUCTION

Peripartum cardiomyopathy (PPCM) is a rare but potentially fatal disease defined by heart failure towards the end of pregnancy or in the months following delivery. We aim to raise awareness of the condition and give the clinician an overview of current knowledge on the mechanisms of pathophysiology, diagnostics and clinical management.

MATERIAL AND METHODS

Systematic literature searches were performed in PubMed and Embase up to June 2016. Cohorts of more than 20 women with PPCM conducted after 2000 were selected to report contemporary outcomes and prognostic data. Guidelines and reviews that provided comprehensive overviews were included, too.

RESULTS

New research on the pathophysiological mechanisms of PPCM points towards a two-hit multifactorial cause involving genetic factors and an antiangiogenic hormonal environment of late gestation with high levels of prolactin and sFlt-1. The prevalence of concomitant preeclampsia is high (often 30-45%) and symptoms can be similar, posing diagnostic difficulties. Most women (71-98%) present postpartum. Echocardiography is essential for diagnosis, and cardiac magnetic resonance imaging may provide new insights to pathophysiology and prognosis. Management is multidisciplinary and involves advanced heart failure therapy. Treatment, timing and mode of delivery in pregnant women depend on disease severity. The risk of relapse in subsequent pregnancies is >20%, and women are often advised against a new pregnancy.

CONCLUSIONS

PPCM has a huge impact on cardiovascular health and reproductive life perspective. New insights into genetics, molecular pathophysiological mechanisms and clinical studies have resulted in potential disease-specific therapies, but many questions remain unanswered.

Cardiac nuclear receptors: architects of mitochondrial structure and function

The adult heart is uniquely designed and equipped to provide a continuous supply of energy in the form of ATP to support persistent contractile function. This high-capacity energy transduction system is the result of a remarkable surge in mitochondrial biogenesis and maturation during the fetal-to-adult transition in cardiac development. Substantial evidence indicates that nuclear receptor signaling is integral to dynamic changes in the cardiac mitochondrial phenotype in response to developmental cues, in response to diverse postnatal physiologic conditions, and in disease states such as heart failure. A subset of cardiac-enriched nuclear receptors serve to match mitochondrial fuel preferences and capacity for ATP production with changing energy demands of the heart. In this Review, we describe the role of specific nuclear receptors and their coregulators in the dynamic control of mitochondrial biogenesis and energy metabolism in the normal and diseased heart.

Human Prolactin Point Mutations and Their Projected Effect on Vasoinhibin Generation and Vasoinhibin-Related Diseases

BACKGROUND

A dysregulation of the generation of vasoinhibin hormones by proteolytic cleavage of prolactin (PRL) has been brought into context with diabetic retinopathy, retinopathy of prematurity, preeclampsia, pregnancy-induced hypertension, and peripartum cardiomyopathy. Factors governing vasoinhibin generation are incompletely characterized, and the composition of vasoinhibin isoforms in human tissues or compartments, such as the circulation, is unknown. The aim of this study was to determine the possible contribution of PRL point mutations to the generation of vasoinhibins as well as to project their role in vasoinhibin-related diseases.

METHODS

Prolactin sequences, point mutations, and substrate specificity information about the PRL cleaving enzymes cathepsin D, matrix metalloproteinases 8 and 13, and bone-morphogenetic protein 1 were retrieved from public databases. The consequences of point mutations in regard to their possible effect on vasoinhibin levels were projected on the basis of a score indicating the suitability of a particular sequence for enzymatic cleavage that result in vasoinhibin generation. The relative abundance and type of vasoinhibin isoforms were estimated by comparing the relative cleavage efficiency of vasoinhibin-generating enzymes.

RESULTS

Six point mutations leading to amino acid substitutions in vasoinhibin-generating cleavage sites were found and projected to either facilitate or inhibit vasoinhibin generation. Four mutations affecting vasoinhibin generation in cancer tissues were found. The most likely composition of the relative abundance of vasoinhibin isoforms is projected to be 15 > 17.2 > 16.8 > 17.7 > 18 kDa vasoinhibin.

CONCLUSION

Prolactin point mutations are likely to influence vasoinhibin levels by affecting the proteolysis efficiency of vasoinhibin-generating enzymes and should be monitored in patients with vasoinhibin-related diseases. Attempts to characterize vasoinhibin-related diseases should include the 15, 17.2, 16.8, 17.7, and 18 kDa vasoinhibin isoforms.

Angiogenic Imbalance and Residual Myocardial Injury in Recovered Peripartum Cardiomyopathy Patients

Background—

Recent studies suggest that angiogenic imbalance during pregnancy may lead to acute peripartum cardiomyopathy (PPCM). We propose that angiogenic imbalance and residual cardiac dysfunction may exist even after recovery from PPCM.

Methods and Results—

Twenty-nine women at least 12 months after presentation with PPCM, who exhibited recovery of left ventricular (LV) ejection fraction (≥50%), were included in the study (mean age 35±6 years, LV ejection fraction 61.0±3.9%). The number of circulating endothelial progenitor cells (EPCs) and plasma levels of proangiogenic vascular endothelial growth factor and of soluble vascular endothelial growth factor receptor Flt1 (sFlt1) were measured. All patients underwent comprehensive cardiac function assessment, including tissue Doppler imaging and 2-dimensional (2D) strain echocardiography. All measurements were compared with healthy controls. Patients with a history of PPCM have significantly higher sFlt1 concentrations (median [25th–75th percentile]; 149.57, [63.14–177.89] versus 20.29, [15.00–53.89] pg/mL, P <0.001) and significantly decreased vascular endothelial growth factor/sFlt1 ratio ( P =0.012) compared with controls, with a trend toward lower concentration of circulating CD34 + /KDR + levels. In addition, patients with PPCM had lower early velocities E′ septal (9.9±2.1 versus 11.0±1.5 cm/s, P =0.02), with a significantly lower systolic velocity S′ septal (7.6±1.2 versus 8.5±1.2 cm/s, P =0.003) by tissue Doppler imaging. Significantly lower LV global longitudinal (−19.1±3.3 versus −22.7±2.2%, P <0.001) and apical circumferential 2D strain (−16.6±4.9 versus −21.2±7.9, P =0.02) were present in patients with PPCM compared with controls.

Conclusions—

Higher concentration of sFlt1 with concomitant decreased circulating endothelial progenitor cell levels along with inappropriate attenuated vascular endothelial growth factor levels may imply an angiogenic imbalance that exists even after recovery and may thus predispose to PPCM. In addition, tissue Doppler imaging and 2D strain were able to identify residual myocardial injury in post-PPCM women with apparent recovery of LV systolic function. Both angiogenic imbalance and residual myocardial injury may play an important role in the recurrence of LV dysfunction during subsequent pregnancies.

Vascular Toxicities of Cancer Therapies: The Old and the New--An Evolving Avenue

Since the late 1990s, there has been a steady decline in cancer-related mortality, in part related to the introduction of so-called targeted therapies. Intended to interfere with a specific molecular pathway, these therapies have, paradoxically, led to a number of effects off their intended cancer tissue or molecular targets. The latest examples are tyrosine kinase inhibitors targeting the Philadelphia Chromosome mutation product, which have been associated with progressive atherosclerosis and acute vascular events. In addition, agents designed to interfere with the vascular growth factor signaling pathway have vascular side effects ranging from hypertension to arterial events and cardiomyocyte toxicity. Interestingly, the risk of cardiotoxicity with drugs such as trastuzumab is predicted by preexisting cardiovascular risk factors and disease, posing the question of a vascular component to the pathophysiology. The effect on the coronary circulation has been the leading explanation for the cardiotoxicity of 5-fluorouracil and may be the underlying the mechanism of presentation of apical ballooning syndrome with various chemotherapeutic agents. Classical chemotherapeutic agents such as cisplatin, often used in combination with bleomycin and vinca alkaloids, can lead to vascular events including acute coronary thrombosis and may be associated with an increased long-term cardiovascular risk. This review is intended to provide an update on the evolving spectrum of vascular toxicities with cancer therapeutics, particularly as they pertain to clinical practice, and to the conceptualization of cardiovascular diseases, as well. Vascular toxicity with cancer therapy: the old and the new, an evolving avenue.

Relaxin-2 and Soluble Flt1 Levels in Peripartum Cardiomyopathy: Results of the Multicenter IPAC Study

OBJECTIVES

This study explored the association of vascular hormones with myocardial recovery and clinical outcomes in peripartum cardiomyopathy (PPCM).

BACKGROUND

PPCM is an uncommon disorder with unknown etiology. Angiogenic imbalance may contribute to its pathophysiology.

METHODS

In 98 women with newly diagnosed PPCM enrolled in the Investigation in Pregnancy Associated Cardiomyopathy study, serum was obtained at baseline for analysis of relaxin-2, prolactin, soluble fms-like tyrosine kinase 1 (sFlt1), and vascular endothelial growth factor (VEGF). Left ventricular ejection fraction (LVEF) was assessed by echocardiography at baseline and 2, 6, and 12 months.

RESULTS

Mean age was 30 ± 6 years, with a baseline of LVEF 0.35 ± 0.09. Relaxin-2, prolactin, and sFlt1 were elevated in women presenting early post-partum, but decreased rapidly and were correlated inversely with time from delivery to presentation. In tertile analysis, higher relaxin-2 was associated with smaller left ventricular systolic diameter (p = 0.006) and higher LVEF at 2 months (p = 0.01). This was particularly evident in women presenting soon after delivery (p = 0.02). No relationship was evident for myocardial recovery and prolactin, sFlt1 or VEGF levels. sFlt1 levels were higher in women with higher New York Heart Association functional class (p = 0.01) and adverse clinical events (p = 0.004).

CONCLUSIONS

In women with newly diagnosed PPCM, higher relaxin-2 levels soon after delivery were associated with myocardial recovery at 2 months. In contrast, higher sFlt1 levels correlated with more severe symptoms and major adverse clinical events. Vascular mediators may contribute to the development of PPCM and influence subsequent myocardial recovery. (Investigation in Pregnancy Associate Cardiomyopathy [IPAC]; NCT01085955).

Characteristics and In-Hospital Outcomes of Peripartum Cardiomyopathy Diagnosed During Delivery in the United States From the Nationwide Inpatient Sample (NIS) Database

BACKGROUND

Peripartum cardiomyopathy (PPCM) is associated with advanced maternal age, African-American race, hypertensive disorders of pregnancy, and multiple-gestation pregnancies. Less is known regarding racial differences in risk factors and predictors of adverse in-hospital outcomes.

METHODS AND RESULTS

A total of 1,337 women with PPCM were identified with the use of the Nationwide Inpatient Sample (2004-2011). Clinical profiles and maternal outcomes in delivering mothers with and without PPCM were compared and stratified by race. In multivariate analysis, established risk factors for PPCM were confirmed. Anemia (odds ratio [OR] 2.0, 95% confidence interval [CI] 1.6-2.5; P < .0001), asthma (OR 2.2, 95% CI 1.5-3.2; P = .0002), smoking (OR 33.6, 95% CI 9.3-159.4; P < .0001), and thyroid disease (OR 5.9; 95% CI 1.5-21.3; P = .01) were associated with PPCM. Risk factors significant in whites, African Americans, and Hispanics were hypertension during pregnancy and anemia. Patients with PPCM had higher rates of in-hospital adverse outcomes (P < .0001), but no differences in race or comorbidities predicted adverse events.

CONCLUSIONS

Hypertensive disorders during pregnancy and anemia were associated with PPCM in whites, African Americans, and Hispanics, providing further evidence that vascular stress may play a role in the pathogenesis of PPCM. Thyroid disorders may represent a novel risk factor for PPCM.

Shared Genetic Predisposition in Peripartum and Dilated Cardiomyopathies

Background Peripartum cardiomyopathy shares some clinical features with idiopathic dilated cardiomyopathy, a disorder caused by mutations in more than 40 genes, including TTN, which encodes the sarcomere protein titin. Methods In 172 women with peripartum cardiomyopathy, we sequenced 43 genes with variants that have been associated with dilated cardiomyopathy. We compared the prevalence of different variant types (nonsense, frameshift, and splicing) in these women with the prevalence of such variants in persons with dilated cardiomyopathy and with population controls. Results We identified 26 distinct, rare truncating variants in eight genes among women with peripartum cardiomyopathy. The prevalence of truncating variants (26 in 172 [15%]) was significantly higher than that in a reference population of 60,706 persons (4.7%, P=1.3×10(-7)) but was similar to that in a cohort of patients with dilated cardiomyopathy (55 of 332 patients [17%], P=0.81). Two thirds of identified truncating variants were in TTN, as seen in 10% of the patients and in 1.4% of the reference population (P=2.7×10(-10)); almost all TTN variants were located in the titin A-band. Seven of the TTN truncating variants were previously reported in patients with idiopathic dilated cardiomyopathy. In a clinically well-characterized cohort of 83 women with peripartum cardiomyopathy, the presence of TTN truncating variants was significantly correlated with a lower ejection fraction at 1-year follow-up (P=0.005). Conclusions The distribution of truncating variants in a large series of women with peripartum cardiomyopathy was remarkably similar to that found in patients with idiopathic dilated cardiomyopathy. TTN truncating variants were the most prevalent genetic predisposition in each disorder.