Peripartum cardiomyopathy in the era of cardiac magnetic resonance imaging: first results and perspectives

Peripartum Cardiomyopathy: Current Understanding of Pathophysiology, Diagnostic Workup, Management, and Outcomes

Peripartum cardiomyopathy (PPCM) is a relatively rare, potentially life-threatening, idiopathic form of cardiomyopathy that affects previously healthy young women during late pregnancy or in the early postpartum period and is characterized by left ventricular (LV) systolic dysfunction in the absence of any other identifiable cardiac causes. Morbidity and mortality with PPCM are remarkably high and it continues to be one of the leading causes of maternal death. Although remarkable advances have been made in our understanding of PPCM in the last few decades, unanswered questions remain regarding its pathophysiology, diagnostic workup, and management options. In this article, we will complete an updated, comprehensive review of PPCM, including the epidemiology and risk factors, proposed etiology, presentation and complications, management, prognostic indicators and outcomes. In addition, we will identify current challenges and gaps in knowledge.

Anesthetic Management in Peripartum Cardiomyopathy: A Contemporary Review

Peripartum cardiomyopathy (PPCM) is an uncommon disorder of the cardiovascular system and is linked to high rates of morbidity and mortality. It is an idiopathic condition characterized by left ventricular systolic dysfunction with an ejection fraction of approximately 45% near the end of pregnancy or immediately after delivery. Anesthesia management in these women is challenging due to low physiological reserve and potential negative effects on the fetus. To ensure that mother and child are supported safely through delivery, careful anesthesia control is required. Here, in this review article, we discuss the anesthetic implications in preoperative, operative, and postoperative phases in women with perioperative cardiomyopathy undergoing vaginal delivery or cesarean section.

Echocardiographic assessment and critical care management of peri-partum women with unexpected left ventricular failure

Introduction

Cardiac disease remains the largest single cause of maternal death. Whilst uncommon, left ventricular failure during pregnancy and delivery can be devastating to both mother and child. Echocardiography can play a significant role in rapidly establishing a diagnosis, guiding initial therapy and then monitoring response.

Clinical vignettes

The history, presentation and management of three cases of peri-partum left ventricular failure is examined: stress cardiomyopathy in a 34 year old with twins, left ventricular dysfunction secondary to pre-eclampsia in a 22 year old with a singleton pregnancy and a true peri-partum cardiomyopathy in a 42 year old with IVF twins. The defining risk factors, presenting characteristics and echocardiographical findings for each pathology are highlighted.

Conclusion

Echocardiography is playing an increasingly important role in the immediate assessment and management of left ventricular failure. This is especially true in the peri-partum woman, where establishing the correct therapy is both challenging and crucial due to the significant cardiovascular changes that occur around the time of delivery. To this end we believe that echocardiography should be rapidly available to guide the management of these patients by a multidisciplinary team made up of obstetricians, cardiologists, anaesthetists and intensive care physicians.

The Role of Multimodality Cardiovascular Imaging in Peripartum Cardiomyopathy

The burden of pregnancy-related heart disease has dramatically increased over the last decades due to the increasing age at first pregnancy and higher prevalence of cardiovascular risk factors such as diabetes, hypertension, and obesity. Pregnancy is associated with physiological changes in the cardiovascular system, including hemodynamic, metabolic, and hormonal adaptations to meet the increased metabolic demands of the mother and fetus. It has been postulated that pregnancy may act as a cardiovascular stress test to identify women at high risk for heart disease, where the inability to adequately adapt to the physiologic stress of pregnancy may reveal the presence of genetic susceptibility to cardiovascular disease or accelerate the phenotypic expression of both inherited and acquired heart diseases, such as peripartum cardiomyopathy (PPCM). PPCM is a rare and incompletely understood clinical condition. Despite recent advances in the understanding of its pathogenesis, PPCM is not attributable to a well-defined pathological mechanism, and therefore, its diagnosis still relies on the exclusion of overlapping dilated phenotypes. Cardiac imaging plays a key role in any peripartum woman with signs and symptoms of heart failure in establishing the diagnosis, ruling out life-threatening complications, guiding therapy and conveying prognostic information. Echocardiography represents the first-line imaging technique, given its robust diagnostic yield and its favorable cost-effectiveness. Cardiovascular magnetic resonance is a biologically safe high-throughput modality that allows accurate morpho-functional assessment of the cardiovascular system in addition to the unique asset of myocardial tissue characterization as a pivotal piece of information in the pathophysiological puzzle of PPCM. In this review, we will highlight current evidence on the role of multimodality imaging in the differential diagnosis, prognostic assessment, and understanding of the pathophysiological basis of PPCM.

Contemporary considerations for the use of cardiovascular magnetic resonance imaging during pregnancy

Cardiovascular imaging during pregnancy is frequently used to help direct diagnosis and management for women with known or suspected cardiac disease. Although echocardiography is the most commonly used imaging modality in pregnancy, cardiovascular magnetic resonance imaging is an important and increasingly used tool, which can provide complementary, and oftentimes incremental, information regarding cardiovascular anatomy, ventricular function, and vascular flows. Advantages of cardiovascular magnetic resonance imaging over echocardiography and other imaging techniques include superior reproducibility, excellent cross-sectional evaluation of cardiac structures, high spatial resolution, and lack of ionizing radiation (a limitation of computed tomography and conventional catheter-based angiography). Cardiovascular magnetic resonance imaging in the absence of gadolinium-based contrast agents poses no known risk to the mother or fetus and its applications in pregnancy are expanding. Clinicians should be familiar with the role of cardiovascular magnetic resonance imaging in pregnancy to optimize and enhance care for mothers with heart disease.

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.

Current knowledge and recent development on management of peripartum cardiomyopathy

Heart failure with left ventricular dysfunction occurring during pregnancy or during the post-partum period in patients without history of cardiovascular disease defines peripartum cardiomyopathy (PPCM). PPCM carries a high morbidity and mortality rate as well as the possibility of recovery ad integrum. Its incidence shows ethnic variations, with a greater prevalence of the disease among women with African descent. Pathogenesis of PPCM remains poorly understood. Both "oxidative stress-prolactin axis" and "anti-angiogenic-signaling excess" hypotheses are currently being investigated. Novel diagnostic strategies and biomarkers are currently being evaluated. Besides conventional treatment of heart failure, targeted therapies such as pharmacological prolactin blockade are under evaluation. The aim of this short review is to highlight current management as targeted therapy has far been disappointing.

[Peripartum cardiomyopathy]

The peripartum cardiomyopathy is a rare form of dilated cardiomyopathy resulting from alteration of angiogenesis toward the end of pregnancy. The diagnosis is based on the association of clinical heart failure and systolic dysfunction assessed by echocardiography or magnetic resonance imaging. Diagnoses to rule out are myocardial infarction, amniotic liquid embolism, myocarditis, inherited cardiomyopathy, and history of treatment by anthracycline. Risk factors are advance maternal age (>30), multiparity, twin pregnancy, African origin, obesity, preeclampsia, gestational hypertension, and prolonged tocolytic therapy. Treatment of acute phase is identical to usual treatment of acute systolic heart failure. After delivery, VKA treatment should be discussed in case of systolic function <25% because of higher risk of thrombus. A specific treatment by bromocriptine can be initiated on a case-by-case basis. Complete recovery of systolic function is observed in 50% of cases. The mortality risk is low. Subsequent pregnancy should be discouraged, especially if systolic function did not recover.

Peripartum cardiomyopathy

Peripartum cardiomyopathy (PPCM) is a rare form of unexplained cardiac failure of unknown origin, unique to the pregnant woman with highly variable outcome associated with high morbidity and mortality. PPCM is fraught with controversies in its definition, epidemiology, pathophysiology, diagnosis and management. PPCM is frequently under diagnosed, inadequately treated and without a laid down follow-up regimen, thus, the aim of this review. Publications on PPCM were accessed using Medline, Google scholar and Pubmed databases. Relevant materials on PPCM, selected references from internet services, journals, textbooks, and lecture notes on PPCM were also accessed and critically reviewed. PPCM is multifactorial in origin. It is a diagnosis of exclusion and should be based on classic echocardiographic criteria. The outcome of PPCM is also highly variable with high morbidity and mortality rates. Future pregnancies are not recommended in women with persistent ventricular dysfunction because the heart cannot tolerate increased cardiovascular workload associated with the pregnancy. Although, multiparity is associated with PPCM, there is an increased risk of fetal prematurity and fetal loss. PPCM is a rare form of dilated cardiomyopathy of unknown origin, unique to pregnant women. The pathophysiology is poorly understood. Echocardiography is central to diagnosis of PPCM and effective treatment monitoring in patients of PPCM. The outcome is highly variable and related to reversal of ventricular dysfunction.

Cardiomyopathy classification: ongoing debate in the genomics era

Cardiomyopathies represent a group of diseases of the myocardium of the heart and include diseases both primarily of the cardiac muscle and systemic diseases leading to adverse effects on the heart muscle size, shape, and function. Traditionally cardiomyopathies were defined according to phenotypical appearance. Now, as our understanding of the pathophysiology of the different entities classified under each of the different phenotypes improves and our knowledge of the molecular and genetic basis for these entities progresses, the traditional classifications seem oversimplistic and do not reflect current understanding of this myriad of diseases and disease processes. Although our knowledge of the exact basis of many of the disease processes of cardiomyopathies is still in its infancy, it is important to have a classification system that has the ability to incorporate the coming tide of molecular and genetic information. This paper discusses how the traditional classification of cardiomyopathies based on morphology has evolved due to rapid advances in our understanding of the genetic and molecular basis for many of these clinical entities.

Diagnostic dilemmas in cardiology

A 29-year-old pregnant woman presented in accident and emergency with severe acute left ventricular failure requiring admission to the intensive care unit. A nasal swab was found to be positive for H1N1 making peripartum and viral cardiomyopathies, the most likely differential diagnoses. CT coronary angiography and subsequent invasive angiography revealed an anomalous coronary system thus making ischaemic cardiomyopathy also a possibility. Cardiac MRI played a vital role in identifying the underlying cause, which in this case was that of H1N1 influenza cardiomyopathy. Correct diagnosis in such patients is paramount as this impinges on patients' overall prognosis. In this case aggressive initial therapy including inotropic support and invasive ventilation followed by standard antifailure treatment with β-blockers and angiotensin-converting enzyme inhibitors led to restoration of the patient's left ventricular function and an associated marked improvement in symptoms.

Investigation of cardiomyopathy using cardiac magnetic resonance imaging part 2: Rare phenotypes

Cardiac magnetic resonance imaging (CMRI) has emerged as a useful tertiary imaging tool in the investigation of patients suspected of many different types of cardiomyopathies. CMRI images are now of a sufficiently robust quality to enable high spatial and temporal resolution image acquisition. This has led to CMRI becoming an effective non-invasive imaging tool for many cardiomyopathies. In this two-part review we outline the typical sequences used to image cardiomyopathy and present the imaging spectrum of cardiomyopathy. Part I focused on the current classification of cardiomyopathy, the basic CMRI sequences used in evaluating cardiomyopathy and the imaging spectrum of common phenotypes. Part II illustrates the imaging spectrum of the more rare phenotypes.

Cardiac MR imaging of nonischemic cardiomyopathies: imaging protocols and spectra of appearances

Recent technologic advances in cardiac magnetic resonance (MR) imaging have resulted in images with high spatial and temporal resolution and excellent myocardial tissue characterization. Cardiac MR is a valuable imaging technique for detection and assessment of the morphology and functional characteristics of the nonischemic cardiomyopathy. It has gained acceptance as a standalone imaging modality that can provide further information beyond the capabilities of traditional modalities such as echocardiography and angiography. Black-blood fast spin-echo MR images allow morphologic assessment of the heart with high spatial resolution, while T2-weighted MR images can depict acute myocardial edema. Contrast material-enhanced images can depict and be used to quantify myocardial edema, infiltration, and fibrosis. This review presents recommended cardiac MR protocols for and the spectrum of imaging appearances of the nonischemic cardiomyopathies.

Peripartum cardiomyopathy: review and practice guidelines

Peripartum cardiomyopathy, a type of dilated cardiomyopathy of unknown origin, occurs in previously healthy women in the final month of pregnancy and up to 5 months after delivery. Although the incidence is low-less than 0.1% of pregnancies -morbidity and mortality rates are high at 5% to 32%. The outcome of peripartum cardiomyopathy is also highly variable. For some women, the clinical and echocardiographic status improves and sometimes returns to normal, whereas for others, the disease progresses to severe cardiac failure and even sudden cardiac death. In acute care, treatment may involve the use of intravenous vasodilators, inotropic medications, an intra-aortic balloon pump, ventricular-assist devices, and/or extracorporeal membrane oxygenation. Survivors of peripartum cardiomyopathy often recover from left ventricular dysfunction; however, they may be at risk for recurrence of heart failure and death in subsequent pregnancies. Women with chronic left ventricular dysfunction should be managed according to guidelines of the American College of Cardiology Foundation and the American Heart Association.

Uncharted waters: rare and unclassified cardiomyopathies characterized on cardiac magnetic resonance imaging

Cardiac magnetic resonance imaging (CMR) has undergone considerable technology advances in recent years, so that it is now entering into mainstream cardiac imaging practice. In particular, CMR is proving to be a valuable imaging tool in the detection, morphological assessment and functional assessment of cardiomyopathies. Although our understanding of this broad group of heart disorders continues to expand, it is an evolving group of entities, with the rarer cardiomyopathies remaining poorly understood or even unclassified. In this review, we describe the clinical and pathophysiological aspects of several of the rare/unclassified cardiomyopathies and their appearance on CMR.