Valvular heart disease and pregnancy part II: management of prosthetic valves

Anticoagulant Therapy in Pregnant Women with Mechanical Heart Valves: Italian Federation of Centers for Diagnosis and Surveillance of the Antithrombotic Therapies (FCSA) Position Paper

The management of anticoagulant therapy in pregnant women with mechanical heart valves (MHVs) is difficult and often challenging even for clinicians experienced in the field. These pregnancies, indeed, are burdened with higher rates of complications for both the mother and the fetus, compared to those in women without MHVs. The maternal need for an optimal anticoagulation as provided by vitamin K antagonists is counterbalanced by their teratogen effect on the embryo and fetus. On the other hand, several concerns have been raised about the efficacy of heparins in pregnant women with MHVs, considering the high risk of thrombotic complications in these patients. Therefore, numerous clinical issues about the management of pregnant women with MHVs remain unanswered, such as the selection of the best anticoagulant agent, the optimal anticoagulation levels to be achieved and maintained, and the evaluation of long-term effects for both the mother and the fetus. Based on a comprehensive review of the current literature, the Italian Federation of the Centers for the Diagnosis and the Surveillance of the Antithrombotic Therapies (FCSA) proposes experience-based suggestions and expert opinions. Particularly, this consensus document aims at providing practical guidance for clinicians dealing with pregnant women with MHVs, to optimize maternal and fetal outcomes while guaranteeing adequate anticoagulation. Finally, FCSA highlights the need for the creation of multidisciplinary teams experienced in the management of pregnant women with MHVs during pregnancy, delivery, and postpartum, in order to better deal with such complex clinical issues and provide a comprehensive counseling to these patients.

The multidisciplinary management of a mechanical mitral valve thrombosis in pregnancy: a case report and review of the literature

Background

The management of anticoagulation for mechanical heart valves during pregnancy poses a unique challenge. Mechanical valve thrombosis is a devastating complication for which surgery is often the treatment of choice. However, cardiac surgery for prosthetic valve dysfunction in pregnant patients confers a high risk of maternofetal morbidity and mortality.

Case summary

A 39-year-old woman in her first pregnancy at 30 weeks gestation presented to hospital with a mechanical mitral valve thrombosis despite therapeutic anticoagulation with low-molecular-weight heparin. She underwent an emergent caesarean section followed immediately by a bioprosthetic mitral valve replacement. This occurred after careful planning and organization on the part of a large multidisciplinary team.

Discussion

A proactive, rather than reactive, approach to the surgical management of a mechanical valve thrombosis in pregnancy will maximize the chances of successful maternal and fetal outcomes.

The Safety and Efficacy of Low-Molecular-Weight Heparin in Pregnant Women With Rheumatic Heart Disease and Valves Replacement

Background: In patients with rheumatic heart disease (RHD) and prosthetic valve replacement, the risk of thromboembolic complications is the highest during and immediately after pregnancy. Therapeutic anticoagulation during this period is crucial to minimize the risk of thromboembolic complications. The use of low-molecular-weight heparin (LMWH) remains an off-label indication. The type of anticoagulants used, dosing regimens, target anti-Xa levels, and frequency of anti-Xa monitoring are highly variable in the pregnant population and have been derived from pilots, observational studies, and empirical evidence. Herein, in a real-world setting, we sought to examine the efficacy and safety of variable anticoagulation options with a focus on LMWH in the management of RHD-related valvular disease in pregnant women.

Methods: This study is a retrospective study conducted at a large university-affiliated tertiary care center (King Saud University Medical City) between January 2011 and February 2020. All pregnant women with RHD who had heart valve replacements were reviewed. Patient data were extracted for demographic information, baseline characteristics, anticoagulation type, and primary outcomes. Primary endpoints were thromboembolic events, hemorrhagic complications, and fetal outcomes.

Results: A total of 744 pregnancies in 149 women were identified. The mean age ± SD of the women was 43.8 ± 12 years. A total of 86 women (58%) were on the LMWH regimen, 35 women (23%) were on LMWH and warfarin regimen, and 28 women (19%) were on unfractionated heparin (UFH) and warfarin regimen. Overall, thromboembolic events developed in five (0.7%) pregnancies. Of those, two were in the LMWH group, two were in the LMWH and warfarin group, and one was in the UFH and warfarin group. In addition, significant hemorrhagic complications occurred in five pregnancies. Of these, two occurred in the LMWH group, two in the LMWH and warfarin group, and one in the UFH and warfarin group. No adverse maternal and fetal outcomes were noted.

Conclusion: This study presents the largest retrospective study of variable anticoagulation options in pregnant women with RHD and prosthetic valve replacement. LMWH is both safe and effective in preventing major thromboembolic complications compared to other forms of anticoagulation used during pregnancy.

Care of the patient after valve intervention

This review aims to outline the current evidence base and guidance for care of patients post-valve intervention. Careful follow-up, optimisation of medical therapy, antithrombotics, reduction of cardiovascular risk factors and patient education can help improve patient outcomes and quality of life. Those with mechanical valves should receive lifelong anticoagulation with a vitamin K antagonist but in certain circumstances may benefit from additional antiplatelet therapy. Patients with surgical bioprosthetic valves, valve repairs and transcatheter aortic valve implantation also benefit from antithrombotic therapy. Additionally, guideline-directed medical therapy for coexistent heart failure should be optimised. Cardiovascular risk factors such as hyperlipidaemia, hypertension and diabetes should be treated in the same way as those without valve intervention. Patients should also be encouraged to exercise regularly, eat healthily and maintain a healthy weight. Currently, there is not enough evidence to support routine cardiac rehabilitation in individuals post-valve surgery or intervention but this may be considered on a case-by-case basis. Women of childbearing age should be counselled regarding future pregnancy and the optimal management of their valve disease in this context. Patients should be educated regarding meticulous oral health, be encouraged to see their dentist regularly and antibiotics should be considered for high-risk dental procedures. Evidence shows that patients post-valve intervention or surgery are best treated in a dedicated valve clinic where they can undergo clinical review and surveillance echocardiography, be provided with heart valve education and have access to the multidisciplinary valve team if needed.

Alternatives to Low Molecular Weight Heparin for Anticoagulation in Pregnant Women with Mechanical Heart Valves in Middle-Income Countries: A Cohort Study

Objective

To compare cardiac complications and pregnancy outcomes in women with mechanical heart valves (MHVs) on two different anticoagulation regimens in a middle-income country.

Methods

We conducted a retrospective cohort study comparing outcomes in pregnant women with MHVs that received vitamin K antagonists (VKAs) throughout pregnancy versus sequential anticoagulation (heparins in the first trimester and peripartum period and VKAs for the remainder of pregnancy), at a tertiary centre in South India, from January 2011 to August 2020.

Results

We identified 138 pregnancies in 121 women, of whom 32 received VKAs while 106 were on sequential anticoagulation. There were no differences between groups with regard to maternal deaths [0 vs. 6 (5.7%), p = 0.34], thromboembolic events [2 (6.3%) vs. 15 (14.2%), p = 0.36], haemorrhagic complications [4 (12.5%) vs. 12 (11.3%), p = 0.85], cardiac events [1 (3.1% vs. 17 (16%), p = 0.07], spontaneous miscarriages [5 (15.6%) vs. 13 (12.3%), p = 0.62], stillbirths [0 vs. 5 (5.4%), p = 0.581] or neonatal deaths [2 (8.7%) vs. 1 (1.1%), p = 0.11]. Both cases of warfarin embryopathy received >5 mg warfarin in the first trimester. Thromboembolic events were associated with subtherapeutic doses of heparin in the first and third trimesters and the early postpartum period. Fetal growth restriction and preterm birth complicated 34 (29.3%) and 26 (22.4%) pregnancies respectively.

Conclusion

Pregnancy complications associated with MHVs in middle-income countries may be reduced by multidisciplinary surveillance, avoiding first-trimester warfarin if daily doses >5 mg and ensuring therapeutic levels of heparin during bridging in the first and third trimesters and peripartum period. Administration of low-dose aspirin should be considered as this may prevent placentally-mediated complications of pregnancy.

Highlights

Pregnancy complications associated with MHVs in LMICs may be reduced by multidisciplinary surveillance, avoiding first-trimester warfarin if the daily dose is >5 mg, ensuring therapeutic levels of heparin in the first trimester and peripartum period.Placentally-mediated complications of pregnancy can be prevented by administering low-dose aspirin.Vitamin K antagonists or sequential regimen can be used as suitable alternatives to LMWH for anticoagulation in pregnant women with MHVs.

Canadian Cardiovascular Society: Clinical Practice Update on Cardiovascular Management of the Pregnant Patient

The number of women of childbearing age with cardiovascular disease (CVD) is growing due to increased survival of children with congenital heart disease (CHD). More women are also becoming pregnant at an older age, which is associated with increased co-morbidities including hypertension, diabetes and acquired CVD. Over the last decade the field of cardio-obstetrics has significantly advanced with the development of multidisciplinary cardio-obstetric programs (COPs) to address the increasing burden of CVD in pregnancy. With the introduction of formal COPs, pregnancy outcomes in women with heart disease have improved. COPs provide preconception counseling, antenatal and postpartum cardiac surveillance, labor and delivery planning. Pre-pregnancy counseling by a COP should be offered to women with suspected CVD who are of child bearing age. In those women who present while pregnant, counseling should be performed by a COP as early as possible in pregnancy. The purpose of counseling is to reduce the risk of pregnancy to the mother and fetus whenever possible. This is done through accurate maternal and fetal risk stratification, optimizing cardiac lesions, reviewing safety of medications in pregnancy, and making a detailed plan for the pregnancy, labor and delivery. This Clinical Practice Update highlights the COP approach to pre-pregnancy counseling, risk stratification, and management of commonly encountered cardiac conditions through pregnancy. We highlight "red flags" that should trigger a more timely assessment by a COP. We also describe the approach to some of the cardiac emergencies that the care provider may encounter in a pregnant woman.

Valvular Heart Disease in Pregnancy

Valvular heart disease (VHD) is generally well tolerated during pregnancy; however, the dramatic changes in hemodynamics that occur during pregnancy can lead to clinical decompensation in high-risk women. Women with VHD considering pregnancy should undergo preconception counseling with a high-risk obstetrician and cardiologist to review the maternal, fetal, and obstetric risks of pregnancy and delivery. Vaginal delivery is recommended for most women with VHD. Given the complexity of managing VHD during pregnancy, women should be managed by a multidisciplinary Pregnancy Heart Team during pregnancy, consisting of a high-risk obstetrician, cardiologist, and cardiac anesthesiologist.

Vaginal delivery in a patient with severe aortic stenosis under epidural analgesia, a case report

BACKGROUND

A history of previous cardiac disease increases the maternal mortality risk by as much as 100%. There is no consensus on the absolute contraindications to vaginal delivery in valvular heart disease, but central regional anesthesia is traditionally considered contraindicated in patients with severe aortic stenosis.

CASE PRESENTATION

A 29-year-old primigravid woman with severe aortic stenosis was admitted to the obstetrics department for programmed labor induction. With epidural anesthesia and mini-invasive hemodynamic monitoring labor and operative vaginal delivery were well tolerated, and hemodynamic stability was always maintained.

CONCLUSIONS

Epidural analgesia and oxytocin induction are possible for the labor management of parturients with severe aortic stenosis given that continuous non-invasive followed by invasive hemodynamic monitoring can be provided and given the absence of any obstetric or cardiologic contraindications and the strong will of the patient.

Mechanical heart valves and pregnancy: Issues surrounding anticoagulation. Experience from two obstetric cardiac centres

Background

Pregnant women with mechanical heart valves are at significant risk of obstetric/cardiac complications. This study compares the anticoagulation management in two obstetric cardiac centres.

Methods

Retrospective case-note review from Chelsea and Westminster/Royal Brompton Hospitals (CR) and Erasmus Medical Centre (EMC). Main outcome measure was mechanical heart valve thrombosis.

Results

Nineteen pregnancies from CR and 25 pregnancies from EMC were included. Most women were on low-molecular-weight heparin (LMWH) throughout pregnancy at CR, whereas at EMC most had LMWH in the first trimester and vitamin K antagonists in subsequent trimesters. Peak anti-factor Xa were performed monthly at CR, levels 0.39-1.51 IU/mL (mean 0.82 IU/mL). Anticoagulation management peri-partum was inconsistent. Delivery was mainly by caesarean section at CR (74%) and vaginal delivery at EMC (64%). No maternal deaths and only one mechanical heart valve thrombosis at CR. Two mechanical heart valve thromboses and one maternal death at EMC.

Conclusion

Peri-partum anticoagulation strategies, anticoagulation monitoring and mode of delivery inconsistencies reported.

Pregnancy outcomes in women with mechanical prosthetic heart valves

Pregnancy outcomes in women with mechanical heart valves (MHV) remain poor. The thrombogenicity of MHV, the hypercoagulable state of pregnancy and limitations of current anticoagulation strategies combine to give a very high risk state. Recent additions to the literature in the form of registry data as well as meta-analyses and systematic reviews have highlighted the risks of thrombotic and haemorrhagic events in mothers and increased fetal complication rates. There remains a lack of consensus about the optimal anticoagulation approach to mitigate the risks to mother and fetus and registry data confirm poor quality of care. Current guidelines recommend the sequential use of heparin and vitamin K antagonists, but low molecular weight heparin is often used throughout the pregnancy, with inadequate monitoring in many instances. There is an urgent need to standardise the management of such women, which should be undertaken in specialist centres, supported by research on optimal anticoagulation regimens and the impact on pregnancy outcomes.

Anticoagulation regimens during pregnancy in patients with mechanical heart valves: a protocol for a systematic review and network meta-analysis

INTRODUCTION

Pregnancy in patients with mechanical heart valves (MHVs) is associated with high maternal complications and fetal complications.Anticoagulation treatments serve to decrease their venous clotting risk. Although some anticoagulation regimens have been used for patients during pregnancy with MHVs, no one is definitively superior among different regimens in recent studies. For a better understanding of the clinical treatment which anticoagulation regimen is more effective and safer during the pregnancy in patients with MHVs, a Bayesian network meta-analysis is necessary.

METHODS AND ANALYSIS

This protocol has been reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols. Related studies until April 2019 will be searched in the following databases: PubMed, Embase,SinoMed and the using the OVID interface to search for evidence-based medicine reviews. A clinical trial registry (www.ClinicalTrials.gov) was also searched for unpublished trials. Both experimental studies (randomised clinical trials) and observational studies (cohort studies, case-control studies and case series studies) will be included in this study. Quality assessment will be conducted using Cochrane Collaboration's tool or Newcastle-Ottawa Scale based on their study designs. The primary outcomes of interest will be the frequencies of serious maternal and fetal events. The additional outcomes of interest will be adverse maternal events, mode of delivery and adverse fetal events. Pairwise and network meta-analysis will be conducted using R (V.3.4.4, R Foundation for Statistical Computing, Vienna, Austria) and Stata (V.14, StataCorp). The ranking probabilities will be estimated at each possible rank for each anticoagulation regimen using the surface under the cumulative ranking curve. Statistical inconsistency assessment, subgroup analysis, sensitivity analysis and publication bias assessment will be performed.

ETHICS AND DISSEMINATION

Either ethics approval or patient consent is not necessary, because this study will be based on literature. The results of this study will be published in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42019130659.

Mechanical Aortic Valve Thrombus in Pregnancy: A Case Report

Cardiac disease is one of the leading causes of maternal mortality in developed countries. The presence of a mechanical valve is a predictor of cardiac complications in obstetric patients, likely due to the challenges associated with pregnancy hypercoagulability and the imperative of meticulous management of anticoagulation throughout pregnancy, delivery, and the postpartum and to prevent the devastating event of a mechanical valve thrombosis. We report on the management of a pregnant woman with a mechanical aortic valve found to have a thrombus at 37 weeks gestation. It was decided to perform cesarean delivery to allow for a reoperative mechanical aortic valve replacement 24 hours thereafter.

State of the Art Management of Mechanical Heart Valves During Pregnancy

PURPOSE OF THE REVIEW

To review the management of women with mechanical heart valves during pregnancy, from preconception counseling through delivery with a summary of the latest guidelines.

RECENT FINDINGS

The hypercoagulability of pregnancy combined with the imperfect choices of anticoagulant agents contribute to a high risk of complications in pregnant women with mechanical heart valves. Valve thrombosis remains a major concern, much of which occurs during the first trimester transition to heparin-based products. The safest method of anticoagulation, with the best balance of maternal and fetal risk, is use of low-dose vitamin K antagonists, but only if therapeutic anticoagulation can be achieved with warfarin doses of ≤ 5 mg/day. Management of mechanical heart valves in pregnancy remains fraught with difficult decisions involving balancing of maternal and fetal risks as well as a high risk of maternal and fetal complications. Preconception counseling and planning is imperative. A risk-benefit discussion with the patient will help guide the choice of anticoagulation and outline the plan for safe delivery options. A multidisciplinary approach to management is advisable with close follow-up and care in a tertiary center.