Anticoagulation Therapy for Pregnant Women With Mechanical Prosthetic Heart Valves

Combination anticoagulation strategy in pregnancy with mechanical valves: The KYBELE study

BACKGROUND

Optimal first-trimester anticoagulation is still challenging in pregnant women with mechanical heart valves (MHVs) requiring high-dose warfarin. This multicenter prospective study aims to determine the optimal anticoagulation regimens for pregnant patients with MHVs.

METHODS

All women were allocated to one of three treatment options during first trimester including lone low-molecular-weight heparin (LMWH), combination of LMWH + 2.5 mg warfarin, and LMWH+4 mg warfarin. Primary maternal outcome included a combination of death, thromboembolism, severe bleeding, and need for treatment of mechanical valve thrombosis (MVT). Any fetal loss was determined as primary fetal outcome.

RESULTS

The study included 78 pregnancies in 65 women with MHVs. Primary maternal outcome rate was 44%, 12.5%, 3.5%, respectively. The rates of primary maternal outcome (44 vs 3.5%, P < .001), obstructive MVT (16 vs 0%, P = .04), MVT requiring treatment (28 vs 0%, P = .003), and cerebral embolism (24 vs 3.4%, P = .041) were found to be significantly higher in lone LMWH group compared to LMWH + 4 mg warfarin group. Moreover, the rates of primary maternal outcome (12.5 vs 44%, P = .015) and treatment for MHV thrombus (4.2 vs 28%, P = .049) were significantly lower in LMWH + 2.5 mg warfarin group compared to lone LMWH group. The incidences of fetal loss were 8 (32%) in the lone LMWH group, 8 (33.3%) in LMWH + 2.5 mg warfarin group, and 11 (37.9%) in LMWH + 4 mg warfarin group (P = .890 for 3-group).Warfarin related-embryopathy was not observed in any case.

CONCLUSIONS

The combined anticoagulation strategy of LMWH plus low-dose warfarin during the first trimester of pregnancy may result in less maternal complications with comparable fetal outcomes in patients with MHVs.

CONDENSED ABSTRACT

Low-molecular-weight heparin (LMWH) is thought to be safer for the fetus, however it is suspected to be less protective for the mother. To solve this dilemma, the authors suggested a novel anticoagulation strategy in pregnant women with prosthetic valves. Seventy-eight pregnancies of 65 women (median age 32 [27-35] years) were included in the study. A combination of LMWH and a reduced dose warfarin were associated with low rates of thrombus-related complications in pregnant patients with mechanical heart 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.

Mechanical thrombectomy for acute ischemic stroke with large vessel occlusion in pregnancy with mechanical heart valves： A case report

BACKGROUND

The management of anticoagulation for mechanical heart valves (MHVs) during pregnancy posed a special challenge. Mechanical thrombectomy (MT) was the standard treatment for acute ischemic stroke (AIS) in anterior circulation with large vessel occlusion. However, the efficacy and safety of MT in the treatment of acute ischemic stroke in pregnancy were unknown.

CASE PRESENTATION

A 29-year-old woman with MHVs in her first pregnancy at 7 weeks' gestation underwent MT because of a large occlusive thrombus in the end of the internal carotid artery despite therapeutic anticoagulation with low-molecular-weight heparin. This pregnant woman recovered well after MT with a modified rank score (mRS) of 0 at 90 days.

CONCLUSION

At present, there was no standard protocol of anticoagulation therapy for pregnant women with MHVs. Acute ischemic stroke with large vessel occlusion in pregnancy was rare, but could bring devastating consequences for both mother and infant. Our case report demonstrated that MT could be safe and effective in pregnancy.

Outcomes in Pregnant Women with Valvular Heart Disease from Portuguese-Speaking African Countries Treated in Portugal through an International Agreement of Health Cooperation

Aims

We performed a clinical audit of maternal and fetal outcomes in pregnant women with valvular heart disease (VHD) from Portuguese-speaking African countries who were transferred for their care, during a twenty-year period, through a memorandum of agreement of international cooperation.

Methods and results

A retrospective analysis of 81 pregnancies in 45 patients with VHD (median age 24, interquartile range 22-29 years) from 2000 to 2020 was performed. The main outcome measures were maternal cardiovascular and fetal outcomes. History of rheumatic heart disease was present in 60 (74.1%) pregnancies. Most were in New York Heart Association (NYHA) functional class I or II; at the first evaluation, 35 (43.2%) were on cardiac medication and 49 (60.5%) were anticoagulated. Forty-eight pregnancies had at least one valvular prosthesis, including 38 mechanical heart valves. During pregnancy, deterioration in NYHA functional class occurred in 35 (42.0%), and eight (9.9%) patients required initiation or intensified cardiac medication. Mechanical valve thrombosis complicated four (4.9%) pregnancies, all cases on heparin, and resulted in one maternal death. Haemorrhagic complications happened in 7 (8.6%) anticoagulated patients, in the immediate postpartum or puerperal period. The 81 pregnancies resulted in 56 (69.1%) live births, while miscarriage and fetal malformations occurred in 19 (23.5%) and 12 (14.8%) pregnancies, respectively. In multivariate analysis, vitamin K antagonist therapy was the only independent predictor of an unsuccessful pregnancy (p = 0.048).

Conclusion

In a high-income country, successful pregnancy was possible with low rate of maternal events in women with VHD transferred from five low-middle income countries in Africa. The use of anticoagulation with a vitamin K antagonist was associated with an unsuccessful pregnancy.

Anticoagulation for mechanical heart valves during pregnancy: A case report and a literature review

RATIONALE

Most previous treatment guidelines for pregnant women with mechanical heart valves recommend that low molecular weight heparin (LMWH) should be applied once every 12 hours and only as required to reach peak anti-Xa levels of approximately 1.0 to 1.2 IU/mL, but it is commonly associated with subtherapeutic trough levels, consequently with an inadequate level of anticoagulation. Our case report here together with a literature review suggests that dose-adjusted (Target trough anti-Xa levels of 0.6 to 0.7 IU/mL and with peak anti-Xa levels of around 1.0 to 1.2 IU/mL or < 1.5 IU/mL) LMWH should be given thrice daily throughout pregnancy. In addition, the findings of this rare case indicate that a combination of LMWH and warfarin is effective in the treatment of small thromboses in pregnancy.

PATIENT CONCERNS

In the 1st trimester of pregnancy, a 28-year old pregnant female with a mechanical valve had a significant increase in the aortic valve flow rate and suspected mechanical valve thrombosis.

DIAGNOSES

The peak velocity of the pregnant female aortic mechanical valve increased, and mechanical valve thrombosis was suspected.

INTERVENTIONS

We adjusted the enoxaparin sodium dose every 12 hours to 1 injection every 8 hours, with a total daily dose of 160 mL. Based on the original application of LMWH, warfarin (3 mg/day) was recommended.

OUTCOMES

The pregnant woman delivered a live baby by cesarean section, and the peak flow velocity of the mechanical valve in the aortic position was reduced to nearly equivalent to the patient's pre-pregnancy status. The mother and the baby were in good health at the time of discharge.

LESSONS

LMWH is administered twice daily, and anti-Xa trough levels are mostly in a subtherapeutic state, which may lead to insufficient anticoagulation and thrombosis. Dose-adjusted LMWH thrice daily throughout pregnancy is the recommended treatment for pregnant women with mechanical heart valves. The combination of LMWH and warfarin exhibited good efficacy for the treatment of small thromboses.

Society for Maternal-Fetal Medicine Consult Series #61: Anticoagulation in pregnant patients with cardiac disease

Pregnancy in individuals with a mechanical heart valve has been classified as very high risk because of a substantially increased risk of maternal mortality or severe morbidity. Lifelong therapeutic anticoagulation is a principal component of the medical management of mechanical heart valves to prevent valve thrombosis. Anticoagulation regimens indicated outside of pregnancy for patients with mechanical valves should be continued during pregnancy with the possibility of modifications based on the type of valve, the trimester of pregnancy, individual risk tolerance, and circumstances around the time of delivery. The purpose of this document is to provide recommendations regarding the management of anticoagulation for common cardiac conditions complicating pregnancy, including mechanical heart valves, atrial fibrillation, systolic heart failure, and congenital heart disease.

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.

2020 ACC/AHA Guideline for the Management of Patients With Valvular Heart Disease: Executive Summary: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This executive summary of the valvular heart disease guideline provides recommendations for clinicians to diagnose and manage valvular heart disease as well as supporting documentation to encourage their use.

METHODS

A comprehensive literature search was conducted from January 1, 2010, to March 1, 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, Cochrane, Agency for Healthcare Research and Quality Reports, and other selected database relevant to this guideline. Structure: Many recommendations from the earlier valvular heart disease guidelines have been updated with new evidence and provides newer options for diagnosis and treatment of valvular heart disease. This summary includes only the recommendations from the full guideline which focus on diagnostic work-up, the timing and choice of surgical and catheter interventions, and recommendations for medical therapy. The reader is referred to the full guideline for graphical flow charts, text, and tables with additional details about the rationale for and implementation of each recommendation, and the evidence tables detailing the data considered in developing these guidelines.

Thrombosis of mechanical mitral valve prosthesis during pregnancy: An ongoing "saga" in need of comprehensive solutions

Emergency treatment for thrombosed mechanical valve prothesis during pregnancy is not uncommon in low- and middle-income countries. The presence of a mechanical valve continues to be an important cause of maternal morbidity and mortality. There is a pressing need for increasing awareness and feasible solutions for this huge problem. We here describe four patients who needed emergency treatment for thrombosis of mechanical valve prothesis during pregnancy and review the evolving comprehensive strategies for dealing with this issue.

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.

Valvular Heart Disease in Pregnancy

The number of reproductive age women with valvular heart disease is rising and accounts for one third of all heart disease among pregnant women. Severe, symptomatic left-sided cardiac lesions, particularly mitral and aortic stenosis, and mechanical heart valves, are associated with adverse maternal and fetal outcomes. Decreasing maternal and fetal risk requires shared decision-making among patients and the heart team, consisting of obstetricians, maternal-fetal medicine subspecialists, and cardiologists.

Comparison of Different Anticoagulation Regimens Regarding Maternal and Fetal Outcomes in Pregnant Patients With Mechanical Prosthetic Heart Valves (from the Multicenter ANATOLIA-PREG Registry)

Mechanical prosthetic heart valves (MPHVs) are highly thrombogenic, and a pregnancy-induced procoagulant status increases the risk of MPHV thrombosis. Despite numerous case reports, 2 major registries and meta-analyses/systematic reviews, optimal anticoagulation therapy during pregnancy remains controversial. The goal of this study was to evaluate different anticoagulation regimens in pregnant patients with MPHVs. The outcomes of anticoagulation regimens were assessed retrospectively in pregnant women (110 women; 155 pregnancies) with MPHVs. The study population was divided into 5 groups according to anticoagulation regimens used; high-dose warfarin (>5 mg/d) throughout pregnancy (group 1), low-dose warfarin (≤5 mg/d) throughout pregnancy (group 2), low molecular weight heparin (LMWH) throughout pregnancy (group 3), first trimester LMWH, 2nd and 3rd trimester warfarin (group 4), first 2 trimester LMWH, and 3rd trimester warfarin (group 5). Of 155 pregnancies, 55 (35%) resulted in fetal loss; whereas 41 (27%) cases with abortion (miscarriage and therapeutic) and 14 (9%) stillbirths occurred. The comparison of the groups showed that the whole abortion rates including therapeutic abortion were significantly higher in Group 1, and lower in groups 3 and 5 (p <0.001). However, miscarriage rates were similar between the groups. A total of 53 pregnancies (34%) suffered from prosthetic valves thrombosis (PVT) during pregnancy or in the postpartum period. Group 2 had significantly lower rates of PVT than the other groups (p <0.001). In conclusion, the current data suggests that there is no optimal therapy, and that all managements have advantages and disadvantages. Low-dose warfarin (≤5 mg/day) regimen with therapeutic international normalized ratio levels may provide effective maternal protection throughout pregnancy with acceptable fetal outcomes.

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.

Morbidity in Pregnant Women with a Prosthetic Heart Valve

BACKGROUND

Women with a prosthetic heart valve are perceived to be at higher risk for adverse outcomes, but their absolute and relative risk of experiencing maternal morbidity and cardiac complications is largely unknown.

OBJECTIVE

The objective of the study was to determine the risk of maternal morbidity and cardiac complications in women with a prior heart valve replacement, compared with matched counterparts without known cardiac disease.

STUDY DESIGN

A retrospective population-based matched cohort study was completed in the province of Ontario, Canada, where there is universal health care. Included were all women of child-bearing age who had bioprosthetic or mechanical replacement of the mitral or aortic valve, April 1994 to March 2016 (valve replacement group). Those in the valve replacement group, and who had at least 1 birth, were 1:4 matched to a community comparison group without heart disease and who also had at least 1 birth. Matching was by maternal age at cohort entry, year of cohort entry, geographic area, income level, and age at first birth. Maternal outcomes included severe maternal morbidity, all-cause mortality, and cardiac morbidity as well as a prolonged hospital length of stay >7 days. Relative risks and 95% confidence intervals were further adjusted for age at birth and immigration status.

RESULTS

There were 90 live births among the 64 women in the valve replacement group and 404 live births among the 253 women in the matched community comparison group. There were no stillbirths. Severe maternal morbidity occurred in 13 pregnancies (14.4%) in the valve replacement group and 6 (1.5%) in the community comparison group (adjusted relative risk, 9.73, 95% confidence interval, 3.70-25.59); there were no maternal deaths. The corresponding rates of prolonged hospital length of stay were 37.8% and 18.8% (adjusted relative risk, 2.33, 95% confidence interval, 1.48-3.67).

CONCLUSION

Pregnant women who had aortic or mitral valve replacement were more likely to experience severe maternal morbidity, as well as prolonged hospital length of stay, than matched counterparts without heart disease. This information can enhance shared decision making about the timing of valve replacement and pregnancy planning in young and middle-aged women. To determine the absolute and relative risk of maternal morbidity and cardiac complications in women with prior heart valve replacement, a retrospective population-based matched cohort study was completed in the province of Ontario, Canada, where there is universal health care. Included were all women of child-bearing age who had bioprosthetic or mechanical replacement of the mitral or aortic valve, April 1994 to March 2016 (valve replacement group). Those in the valve replacement group, and who had at least one birth, were 1:4 matched to a community comparison group without heart disease and who also had at least 1 birth. There were 90 live births among the 64 women in the valve replacement group and 404 live births among the 253 women in the matched community comparison group. Severe maternal morbidity occurred in 13 pregnancies (14.4%) in the valve replacement group and 6 (1.5%) in the community comparison group (adjusted relative risk, 9.73); there were no maternal deaths. The corresponding rates of prolonged hospital length of stay were 37.8% and 18.8% (adjusted relative risk, 2.33). In summary, pregnant women who had an aortic or mitral valve replacement were more likely to experience severe maternal morbidity, as well as prolonged hospital length of stay, than matched counterparts without heart disease.

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.