Causes and treatment strategies of unilateral leaflet escape of bileaflet mechanical prosthetic heart valves after surgery: a case series

BACKGROUND

During the eleven years from 2010 to 2021, preliminary statistics have shown that Fuwai Hospital completed 23,571 mechanical valve replacements for various types of valves, and 1139 mechanical valve replacements were performed in Guangyuan First People's Hospital. Only two patients developed valve leaflet escape, so valve leaflet escape is a rare postoperative complication.

CASE PRESENTATION

In 2010 and 2021, two patients were selected after they had unilateral leaflet escape after having mechanical valve replacements in Fuwai Hospital of Chinese Academy of Medical Sciences and Guangyuan First People's Hospital. Both patients underwent reoperations with the classic operation and the new bileaflet mechanical prosthetic heart valve was sutured. The treatment of detached single lobe and distal vessel was comprehensively determined, and the condition was treated according to the patient's symptoms, CT results, ultrasound results and other test results, as well as whether this detached lobe caused any abnormal hemodynamics of the distal vessel. The patient with mechanical aortic valve escape completed the 10-year follow-up, and patient with mechanical mitral valve escape completed the 3-month follow-up. there was no thrombosis or hematoma at the embolic site; the patient had no lower limb symptoms.

CONCLUSIONS

The reason for the leaflet escape may be related to the valve design and the leaflet material. If the detached leaflets are damaged and if the distal blood vessels are affected, simultaneous surgical treatment is required. Those patients whose vessels were not damaged by the valve lobe should be carefully monitored.

Mechanical Heart Valves, Pregnancy, and Bleeding: A Systematic Review and Meta-Analysis

Anticoagulant therapy is essential in pregnant women with mechanical heart valves to prevent valve thrombosis. The risk of bleeding complications in these patients has not gained much attention. This systematic review and meta-analysis investigate the prevalence of bleeding peri-partum and post-partum in women with mechanical heart valves and also investigate whether bleeding risk differed across anticoagulant regimens or according to delivery mode. The present study was conducted according to The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement. Studies reporting bleeding prevalence in pregnant women with mechanical heart valves receiving anticoagulant therapy were identified through PubMed and Embase on December 08, 2021. Data on bleeding complications, delivery mode, and anticoagulation therapy were extracted. A total of 37 studies were included, reporting 423 bleeding complications in 2,508 pregnancies. A meta-analysis calculated a pooled prevalence of 0.13 (95% confidence interval [CI]: 0.09-0.18) bleeding episodes per pregnancy across anticoagulant regimens. The combination of unfractionated heparin (UFH) and vitamin K antagonist (VKA) and single VKA therapy showed the lowest risk of bleeding (8 and 12%). Unexpectedly, the highest risk of bleeding was found in women receiving a combination of low-molecular-weight-heparin (LMWH) and VKA (33%) or mono-therapy with LMWH (22%). However, this could be dose related. No difference in bleeding was found between caesarean section versus vaginal delivery (p = 0.08). In conclusion, bleeding episodes are common during pregnancy in women with mechanical heart valves receiving anticoagulant therapy. A combination of UFH and VKA or VKA monotherapy showed the lowest risk of bleeding.

Surgical Management of Complex Aortic Valve Disease in Young Adults: Repair, Replacement, and Future Alternatives

The ideal aortic valve substitute in young adults remains unknown. Prosthetic valves are associated with a suboptimal survival and carry a significant risk of valve-related complications in young patients, mainly reinterventions with tissue valves and, thromboembolic events and major bleeding with mechanical prostheses. The Ross procedure is the only substitute that restores a survival curve similar to that of a matched general population, and permits a normal life without functional limitations. Though the risk of reintervention is the Achilles' heel of this procedure, it is very low in patients with aortic stenosis and can be mitigated in patients with aortic regurgitation by tailored surgical techniques. Finally, the Ozaki procedure and the transcatheter aortic valve implantation are seen by many as future alternatives but lack evidence and long-term follow-up in this specific patient population.

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.

Bleeding and thrombotic risk in pregnant women with Fontan physiology

BACKGROUND/OBJECTIVES

Pregnancy may potentiate the inherent hypercoagulability of the Fontan circulation, thereby amplifying adverse events. This study sought to evaluate thrombosis and bleeding risk in pregnant women with a Fontan.

METHODS

We performed a retrospective observational cohort study across 13 international centres and recorded data on thrombotic and bleeding events, antithrombotic therapies and pre-pregnancy thrombotic risk factors.

RESULTS

We analysed 84 women with Fontan physiology undergoing 108 pregnancies, average gestation 33±5 weeks. The most common antithrombotic therapy in pregnancy was aspirin (ASA, 47 pregnancies (43.5%)). Heparin (unfractionated (UFH) or low molecular weight (LMWH)) was prescribed in 32 pregnancies (30%) and vitamin K antagonist (VKA) in 10 pregnancies (9%). Three pregnancies were complicated by thrombotic events (2.8%). Thirty-eight pregnancies (35%) were complicated by bleeding, of which 5 (13%) were severe. Most bleeds were obstetric, occurring antepartum (45%) and postpartum (42%). The use of therapeutic heparin (OR 15.6, 95% CI 1.88 to 129, p=0.006), VKA (OR 11.7, 95% CI 1.06 to 130, p=0.032) or any combination of anticoagulation medication (OR 13.0, 95% CI 1.13 to 150, p=0.032) were significantly associated with bleeding events, while ASA (OR 5.41, 95% CI 0.73 to 40.4, p=0.067) and prophylactic heparin were not (OR 4.68, 95% CI 0.488 to 44.9, p=0.096).

CONCLUSIONS

Current antithrombotic strategies appear effective at attenuating thrombotic risk in pregnant women with a Fontan. However, this comes with high (>30%) bleeding risk, of which 13% are life threatening. Achieving haemostatic balance is challenging in pregnant women with a Fontan, necessitating individualised risk-adjusted counselling and therapeutic approaches that are monitored during the course of pregnancy.

Anti-Xa Monitoring of Low-Molecular-Weight Heparin during Pregnancy: A Systematic Review

Low-molecular-weight heparin (LMWH) is commonly used for preventing or treating venous thromboembolic disease (VTE) during pregnancy. The physiological changes in maternal metabolism have led to discussions on optimal LMWH dosing strategy and possible need for monitoring. The aim of this systematic review is to summarize and discuss whether LMWH dose adjustment according to anti-Xa provides superior effectiveness and safety compared with weight adjusted or fixed dosed LMWH in pregnant women. A systematic literature search was performed in PubMed, Embase, and Scopus on September 26, 2020. The study is reported according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Effectiveness was defined as episodes of thrombosis and safety as bleeding episodes. In total, 33 studies were included: 4 randomized controlled studies and 29 cohort studies. Prophylactic dosing strategies employing weight dosed, fixed dosed, or anti-Xa adjusted LMWH dosing performed equal in effectiveness and safety. In pregnant women with VTE or high thromboembolic risk, therapeutic weight-adjusted LMWH and weight plus anti-Xa-adjusted LMWH provided equal results in terms of effectiveness and safety. Pregnant women with mechanical heart valves (MHVs) received therapeutic anti-Xa-adjusted LMWH with four out of seven studies presenting mean peak anti-Xa within target ranges. Still, pregnant women with MHV experienced both thrombosis and bleeding with anti-Xa in target. Based on the results of this systematic review, current evidence does not support the need for anti-Xa monitoring when using LMWH as thromboprophylaxis or treatment during pregnancy. Nonetheless, the need for anti-Xa monitoring in pregnant women with MHV may need further scrutiny.

Continued use of Warfarin in lower dose has safe maternal and neonatal outcomes in pregnant women with Prosthetic Heart Valves

Background and Objective:

There has been concerns regarding the safety of Warfarin in pregnant females due to its teratogenic potential. At the same time warfarin provides best anticoagulation in patients with prosthetic valves. Various dosage regimes have been tried to strike a balance between safety of mother and the avoidance of congenital anomalies in the newborn. This study was conducted to observe the effect of Warfarin in pregnant mothers taking different doses of warfarin, and their neonatal outcome, in our outdoor patients.

Methods:

This is a cross sectional observational study conducted at the Faisalabad Institute of Cardiology. The pregnant mothers taking warfarin for prosthetic valve replacement who presented to our specialized clinic between November 2016 to April 2017 were included in the study. These included a total of 75 females between the age of 20-35 years. To compare the dose related effect of warfarin, two groups of the patients were formed. One group comprised of patients taking warfarin ≤5mg while the other group consisted of those who were taking >5mg of warfarin daily. These patients were followed till their delivery. The information was collected about the maternal and fetal outcomes. The maternal outcomes including mode of delivery/miscarriage, peripartum bleeding and any valve related thromboembolic complications. The fetal outcomes included birth weight, maturity, embryopathy and congenital anomaly in the baby.

Results:

Patient’s mean age was 29.25±3.75 years. The mitral valve replacement was present in 60% patients (n=45) while 25.3% patients (n=19) had aortic valve replacement and 14.7% patients (n=11) had double valve replacement. In this group 30 patients (40%) had taken <5 mg warfarin and 45 patients (60%) had received >5 mg warfarin medicine. Miscarriages, cesarean sections, low birth weight and prematurity were more common in patients receiving warfarin >5 mg with p-values 0.005, 0.046, 0.01 and 0.033 respectively. No case of fetal embryopathy was found in both groups.

Conclusion:

No case of embryopathy was found in each group which signifies that warfarin in lower doses is safe anticoagulant in patients with prosthetic valve replacements.

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.

Management of Anticoagulation in Pregnant Women With Mechanical Heart Valves

Importance

Mechanical heart valves (MHVs) pose significant thrombogenic risks to pregnant women and their fetuses, yet the choice of anticoagulation in this clinical setting remains unclear. Various therapeutic strategies carry distinct risk profiles that must be considered when making the decision about optimal anticoagulation.

Objective

We sought to review existing data and offer recommendations for the anticoagulation of pregnant women with MHVs, as well as management of anticoagulation in the peripartum period.

Evidence Acquisition

We performed a literature review of studies examining outcomes in pregnant women receiving systemic anticoagulation for mechanical valves, and also reviewed data on the safety profiles of various anticoagulant strategies in the setting of pregnancy.

Results

Warfarin has been shown to increase rates of embryopathy and fetal demise, although it has traditionally been the favored anticoagulant in this setting. Low-molecular-weight heparin, when dosed appropriately with close therapeutic monitoring, has been shown to be safe for both mother and fetus.

Conclusions

We favor the use of low-molecular-weight heparin with appropriate dosing and monitoring for the anticoagulation of pregnant women with MHVs. Data suggest that this approach minimizes the thrombotic risk associated with the valve while also providing safe and effective anticoagulation that can be easily managed in the peripartum period.

Switch from oral anticoagulants to parenteral heparin in SARS-CoV-2 hospitalized patients

The development of COVID-19 syndrome in anticoagulated patients, and especially their admission to intensive-care units with acute severe respiratory syndrome (SARS-CoV-2), expose them to specific problems related to their therapy, in addition to those associated with the acute viral infection. Patients on VKA hospitalized with SARS-CoV-2 show high instability of PT INR due to the variability of vitamin K metabolism, diet, fasting, co-medications, liver impairment, and heart failure. Patients on DOAC are exposed to under/over treatment caused by significant pharmacological interferences. In consideration of the pharmacological characteristics of oral anticoagulant drugs, the multiple pharmacological interactions due to the treatment of acute disease and the possible necessity of mechanical ventilation with hospitalization in intensive-care units, we suggest replacing oral anticoagulant therapies (VKA and DOAC) with parenteral heparin to avoid the risk of over/under treatment.

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.

Description of anti-Xa monitoring practices during low molecular weight heparin use

Certain patient populations (pregnancy, cancer, renal impairment, and obesity) may be at higher risk of adverse events during low molecular weight heparin (LMWH) therapy and may benefit from anti-Xa monitoring. Yet, evidence supporting a standardized approach to anti-Xa monitoring correlated to clinical outcomes is lacking. Patients with at least one documented anti-Xa level and receiving LMWH within a 6-month period were identified. In a 6-month period, 224 adult LMWH patients with 359 anti-Xa levels were identified. Anti-Xa monitoring was most commonly performed in patients with active cancer receiving venous thromboembolism (VTE) treatment doses (57.4%) or obese patients receiving VTE prophylaxis (48.1%). Anti-Xa monitoring during renal impairment and pregnancy were infrequent (0.9% and 1.8%, respectively). Most (71.9%) anti-Xa levels were therapeutic, but only 45% were drawn correctly in relation to LMWH administration time. Compared to those with therapeutic anti-Xa levels, patients with out-of-range levels were four times as likely to receive a LMWH therapy change (odds ratio, 4.16; 95% confidence interval, 2.53-6.84). However, when levels were supratherapeutic or subtherapeutic, the LMWH doses remained unchanged in one-third to one-half of patients, respectively. Anti-Xa monitoring was most commonly performed in patients with cancer or obesity and was more common with VTE prophylaxis dosing. The majority of levels were therapeutic, indicating that anti-Xa monitoring may be unnecessary even in high-risk patient populations. Many out-of-range anti-Xa levels did not prompt a change in LMWH therapy. Further research is still needed to determine if anti-Xa- guided LMWH dosing improves clinical outcomes.

Successful Long-term Anticoagulation with Enoxaparin in a Patient with a Mechanical Heart Valve

Thromboembolism related to a mechanical heart valve (MHV) is a major complication after surgical valve replacement. Warfarin remains as guideline-endorsed thromboprophylaxis in patients with MHVs. Alternative anticoagulation therapy for patients who do not tolerate or who fail warfarin is not adequately covered in the current guidelines. We report a case of successful long-term anticoagulation with enoxaparin in a patient with a mechanical aortic valve who had a contraindication to warfarin. The patient developed a left thigh hematoma requiring surgical evacuation 1 month after initiation of weight-based dosing of enoxaparin. His dose was then titrated based on peak anti-factor Xa levels (goal 0.6-1.0 IU/ml). He remained free of signs and symptoms of thromboembolic events, valve dysfunction, bleeding complications, or major adverse effects from long-term enoxaparin use for the next 13 years. Our case provides promising evidence of the potential role of enoxaparin in patients with MHVs in whom warfarin thromboprophylaxis is not possible. Meticulous monitoring of anti-factor Xa levels and dosage adjustments are crucial to treatment success.

Postpartum anticoagulation in women with mechanical heart valves

Background

Women with mechanical heart valves (MHV) requiring anticoagulation (AC) are at high risk for hemorrhagic complications. Despite guidelines to manage antenatal and peripartum AC, there are few evidence-based recommendations to guide the initiation of postpartum AC. We reviewed our institutional experience of pregnant women with MHV to lay the groundwork for recommendations of immediate postpartum AC therapy.

Study design

This descriptive retrospective cohort used ICD-9 and -10 codes to identify pregnant women with MHV on AC at the Yale-New Haven Hospital from 2007 to 2018. All identified patients were confirmed by chart review. Delivery hospitalization and the immediate postpartum AC management were reviewed. Maternal complications recorded were postpartum hemorrhage, transfusion, wound hematoma, intra-abdominal bleeding, stroke, valve thrombosis, and death. Further, immediate neonatal outcomes were detailed.

Results

Forty-two pregnant women with nonnative heart valves were identified during the study period. From those pregnant women, nine had an MHV and were anticoagulated throughout gestation. Of 19 total pregnancies, 14 met the inclusion criteria. The median gestational age of the delivered pregnancies was early term (37w2d). Nine deliveries were via cesarean (64%). The median time to restart AC after birth was 6 hours. After six deliveries (43%), AC was initiated ≤6 hours postpartum. Hemorrhagic complications occurred in six cases (43%), including wound and intra-abdominal hematomas. Four cases (29%) required blood transfusion. No maternal strokes, thrombotic events, or deaths were recorded. Five (38.5%) neonates required admission to the neonatal intensive care unit.

Conclusion

MHV in pregnancy was rare but was associated with significant maternal morbidity, particularly postpartum hemorrhagic complications. We noted significant variability in the timing of restarting postpartum AC and in the selected agents. Pooled institutional data and an interdisciplinary approach are recommended to minimize competing risks and sequelae of valve thrombosis and obstetrical hemorrhage and, thereby, to optimize maternal outcomes and develop evidence-based guidelines for postpartum AC management.

Pregnancy in Women with Cardiovascular Diseases

Patients with cardiovascular disease represent a significant cohort at risk for complications during pregnancy. The normal physiologic changes of pregnancy could further compromise the hemodynamics of various cardiovascular conditions, resulting in clinical deterioration and even death. The fetus of a gravida with cardiovascular disease also has an increased risk of morbidity, including an increased risk of inherited cardiac genetic disorders, fetal growth restriction, and premature delivery. These complications also increase the risk for antenatal and perinatal mortality. Ideally, the management of a patient with cardiac disease who is considering pregnancy should start with pre-conception counseling that outlines the maternal and fetal complications associated with her particular cardiac disorder. The pregnancy is best managed by a dedicated team of specialists in maternal-fetal medicine, cardiology, cardiovascular surgery, anesthesiology, and neonatology, preferably in a tertiary care center.

Anticoagulation for pregnant women with mechanical heart valves: a systematic review and meta-analysis

Aims

To review maternal and foetal outcomes in women with mechanical heart valves (MHVs) treated with vitamin-K antagonists (VKAs), first-trimester heparin followed by VKAs (sequential treatment), low molecular weight heparin (LMWH) and unfractionated heparin (UFH) during pregnancy, in order to inform practice.

Methods and results

Medline, Embase and Central were searched from inception until February 2016. Two reviewers independently screened 1786 titles, reviewed 110 full-texts and extracted data and assessed risk-of-bias from 46 articles. Pooled incidence (95% confidence intervals) was calculated for maternal and foetal outcomes. Included studies had a moderate or high risk-of-bias. With VKAs, sequential treatment and LMWH, maternal mortality occurred in 0.9% (0.4–1.4), 2.0% (0.8–3.1) and 2.9% (0.2–5.7), thromboembolic complications in 2.7% (1.4–4.0), 5.8% (3.8–7.7) and 8.7% (3.9–13.4), livebirths in 64.5% (48.8–80.2), 79.9% (74.3–85.6) and 92.0% (86.1–98.0) and anticoagulant-related foetal/neonatal adverse events (embryopathy or foetopathy) in 2.0% (0.3–3.7), 1.4% (0.3–2.5) and 0%, respectively. When UFH is used throughout pregnancy, 11.2% (2.8–19.6) suffered thromboembolic complications. Foetal loss and adverse events occurred with first-trimester warfarin doses ≤ 5 mg/day, although there were more livebirths [83.6% (75.8–91.4) vs. 43.9% (32.8–55.0)] and fewer foetal anomalies [2.3% (0.7–4.0) vs. 12.4% (3.3–21.6)] with lower doses than with warfarin > 5 mg/day.

Conclusions

VKAs are associated with fewest maternal complications but also with fewest livebirths. Sequential treatment does not eliminate anticoagulant-related foetal/neonatal adverse events. LMWH is associated with the highest number of livebirths. The safety of UFH throughout pregnancy and first-trimester warfarin  ≤ 5 mg/day remains unconfirmed.

Anticoagulation therapy in pregnant women with mechanical heart valve

Background

This study aims to investigate the effects of various anticoagulant regimens on prosthetic valve-related complications and pregnancy outcomes including feto-maternal mortality and morbidity, and to identify the most optimal anticoagulation therapy regimen.

Methods

Anticoagulant therapy regimens for pregnant women who underwent mechanical heart valve replacement between January 1990 and December 2015 was analyzed retrospectively. Seventy-two pregnancies among 57 patients after mechanical heart valve replacement were reviewed, and four different regimens were identified and evaluated during different trimesters of pregnancy.

Results

Forty of 72 pregnancies resulted in healthy newborns; 35 (48.6%) healthy neonates, four (5.6%) premature births, and one (1.4%) low birth weight. Eighteen (25%) therapeutic and 12 (16.7%) spontaneous abortions, as well as two (2.8%) stillbirths occurred. Seven valve thromboses developed during pregnancy or the postpartum period. Bleeding occurred in six patients (10.5%) and peripheral embolism also occurred in six patients (10.5%). No maternal mortalities were recorded.

Conclusion

Although there is no consensus on the most optimal anticoagulant regimen during pregnancy, substituting warfarin with dose-adjusted unfractionated heparin or low-molecularweight heparin seems suitable to prevent teratogenicity and a high abortion rate in the first trimester. Low-molecular-weight heparin is practical to use and can be monitored reliably, resulting in successful pregnancy outcomes. However, warfarin throughout pregnancy ≤5 mg per day may be an alternative choice, if the risk of embryopathy is accepted by the pregnant woman.

Anticoagulation for the Pregnant Patient with a Mechanical Heart Valve, No Perfect Therapy: Review of Guidelines for Anticoagulation in the Pregnant Patient

Heart valve replacement with a mechanical valve requires lifelong anticoagulation. Guidelines currently recommend using a vitamin K antagonist (VKA) such as warfarin. Given the teratogenic effects of VKAs, it is often favorable to switch to heparin-derived therapies in pregnant patients since they do not cross the placenta. However, these therapies are known to be less effective anticoagulants subjecting the pregnant patient to a higher chance of a thrombotic event. Guidelines currently recommend pregnant women requiring more than 5 mg a day of warfarin be switched to alternative therapy during the first trimester. This case report highlights a patient who was switched to alternative therapy during her first pregnancy and suffered a devastating cerebrovascular accident (CVA). Further complicating her situation was during a subsequent pregnancy; this patient continued warfarin use during the first trimester and experienced multiple transient ischemic attacks (TIAs). This case highlights the increased risk of thrombotic events in pregnant patients with mechanical valves. It also highlights the difficulty of providing appropriate anticoagulation for the pregnant patient who has experienced thrombotic events on multiple anticoagulants.

Outcomes of threatened abortions after anticoagulation treatment to prevent recurrent pregnancy loss

We aimed to determine the outcome of threatened abortion in women treated with low-molecular weight heparin (LMWH) for recurrent pregnancy loss (RPL). Data of women with RPL who experienced threatened abortion while taking LMWH between 2007 and 2016 were retrospectively reviewed. All patients received the LMWH, enoxaparin (40 mg). Thrombophilia was present in 38 (33.3%) women, including 11 (9.6%) with antiphospholipid syndrome (APLS). The overall live birth rate was 58.8% (67/114). Live birth rates were 87.2% (41/47 patients) and 38.8% (26/67 patients) among those who discontinued versus those who continued LMWH treatment, respectively (P < 0.0001). Among APLS patients, live births resulted in eight of the nine women who continued LMWH. In multivariate analysis, discontinuation of LMWH was the only significant predictor of live birth outcome (P < 0.0001). Thrombophilia, presence of subchorionic haematoma, and severity of bleeding were not found to be associated with live birth outcomes. For women with threatened abortions, continuation of LMWH indicated to prevent RPL was negatively associated with live birth rates. Therefore, we support its discontinuation in this setting. Among women with APLS, LMWH continuation resulted in a relatively high live birth rate; we advocate against its withdrawal in this subset of patients.

Management of Pregnancy in Patients With Complex Congenital Heart Disease: A Scientific Statement for Healthcare Professionals From the American Heart Association

Today, most female children born with congenital heart disease will reach childbearing age. For many women with complex congenital heart disease, carrying a pregnancy carries a moderate to high risk for both the mother and her fetus. Many such women, however, do not have access to adult congenital heart disease tertiary centers with experienced reproductive programs. Therefore, it is important that all practitioners who will be managing these women have current information not only on preconception counseling and diagnostic evaluation to determine maternal and fetal risk but also on how to manage them once they are pregnant and when to refer them to a regional center with expertise in pregnancy management.

Maternal and Fetal Outcomes in Pregnant Women with a Prosthetic Mechanical Heart Valve

BACKGROUND

Pregnancy is associated with several cardiocirculatory changes that can significantly impact underlying cardiac disease. These changes include an increase in cardiac output, sodium, and water retention leading to blood volume expansion, and reductions in systemic vascular resistance and systemic blood pressure. In addition, pregnancy results in a hypercoagulable state that increases the risk of thromboembolic complications.

OBJECTIVES

The aim of this study is to assess the maternal and fetal outcomes of pregnant women with mechanical prosthetic heart valves (PHVs).

METHODS

This is a prospective observational study that included 100 pregnant patients with cardiac mechanical valve prostheses on anticoagulant therapy. The main maternal outcomes included thromboembolic or hemorrhagic complications, prosthetic valve thrombosis, and acute decompensated heart failure. Fetal outcomes included miscarriage, fetal death, live birth, small-for-gestational age, and warfarin embryopathy. The relationship between the following were observed:

– Maternal and fetal complications and the site of the replaced valve (mitral, aortic, or double)

– Maternal and fetal complications and warfarin dosage (≤5 mg, >5 mg)

– Maternal and fetal complications and the type of anticoagulation administered during the first trimester

RESULTS

This study included 60 patients (60%) with mitral valve replacement (MVR), 22 patients (22%) with aortic valve replacement (AVR), and 18 patients (18%) with double valve replacement (DVR). A total of 65 patients (65%) received >5 mg of oral anticoagulant (warfarin), 33 patients (33%) received ≤5 mg of warfarin, and 2 patients (2%) received low-molecular-weight heparin (LMWH; enoxaparin sodium) throughout the pregnancy. A total of 17 patients (17%) received oral anticoagulant (warfarin) during the first trimester: 9 patients received a daily warfarin dose of >5 mg while the remaining 8 patients received a daily dose of ≤5 mg. Twenty-eight patients (28%) received subcutaneous (SC) heparin calcium and 53 patients (53%) received SC LMWH (enoxaparin sodium). Prosthetic valve thrombosis occurred more frequently in patients with MVR (P = 0.008). Postpartum hemorrhage was more common in patients with aortic valve prostheses than in patients with mitral valve prostheses (P = 0.005). The incidence of perinatal death was higher in patients with AVR (P = 0.014). The incidence of live birth was higher in patients with DVR (P = 0.012). The incidence of postpartum hemorrhage was higher in patients who received a daily dose of >5 mg of warfarin than in patients who received ≤5 mg of warfarin (P = 0.05). The incidence of spontaneous abortion was also higher in patients receiving >5 mg of warfarin (P ≤ 0.001), while the incidence of live births was higher in patients receiving ≤5 mg of warfarin (P = 0.008). There was a statistically significant difference between the anticoagulant received during the first trimester and cardiac outcomes. Specifically, patients on heparin developed more heart failure (P = 0.008), arrhythmias (P = 0.008), and endocarditis (P = 0.016). There was a statistically significant relationship between heparin shifts during the first trimester and spontaneous abortion (P = 0.003).

CONCLUSION

Warfarin use during the first trimester is safer for the mother but is associated with more fetal loss, especially in doses that exceed 5 mg. The incidence of maternal complications is greater in women who receive LMWH or unfractionated heparin during the first trimester, especially prosthetic valve thrombosis, although the fetal outcome is better because heparin does not cross the placenta.

Guidance for the treatment and prevention of obstetric-associated venous thromboembolism

Venous thromboembolism (VTE), which may manifest as pulmonary embolism (PE) or deep vein thrombosis (DVT), is a serious and potentially fatal condition. Treatment and prevention of obstetric-related VTE is complicated by the need to consider fetal, as well as maternal, wellbeing when making management decisions. Although absolute VTE rates in this population are low, obstetric-associated VTE is an important cause of maternal morbidity and mortality. This manuscript, initiated by the Anticoagulation Forum, provides practical clinical guidance on the prevention and treatment of obstetric-associated VTE based on existing guidelines and consensus expert opinion based on available literature where guidelines are lacking.

Early postpartum mitral valve thrombosis requiring extra corporeal membrane oxygenation before successful valve replacement

Pregnancy is associated with an increased risk of thrombosis in women with mechanical prosthetic heart valves. We present the case of a 29-year-old woman who developed early postpartum mitral valve thrombus after an elective cesarean delivery. The patient had a mechanical mitral valve and was treated with warfarin in the second trimester, which was replaced with high-dose dalteparin during late pregnancy. Elective cesarean delivery was performed under general anesthesia at 37weeks of gestation. The patient was admitted to the intensive care unit for postoperative care and within 30min she developed dyspnea and hypoxia requiring mechanical ventilation. She deteriorated rapidly and developed pulmonary edema, worsening hypoxia and severe acidosis. Urgent extra corporeal membrane oxygenation was initiated. Transesophageal echocardiography revealed a mitral valve thrombus. The patient underwent a successful mitral valve replacement after three days on extra corporeal membrane oxygenation. This case highlights the importance of multidisciplinary care and frequent monitoring of anticoagulation during care of pregnant women with prosthetic heart valves.

Pregnancy and Delivery in Women With Congenital Heart Disease

Because of the growing population of patients with congenital heart disease (CHD), most maternal cardiac disease is now congenital in origin. For women with complex CHD, pregnancy poses an increased risk for both the mother, with complications of arrhythmias and heart failure being the most common, and the baby, with a higher chance of miscarriage, intrauterine growth retardation, and the need for early delivery. Pre-pregnancy counseling must be performed by cardiologists who have expertise in both CHD and pregnancy, with a detailed clinical assessment of the patient and the current hemodynamic situation, including echocardiography and an exercise test. In each case the approach must be individualized with consideration of the risks in each case. In some cases, such as Eisenmenger syndrome, pregnancy is contraindicated. Optimum outcomes in these complex patients are achieved when a multidisciplinary approach is used, involving maternal-fetal medicine specialists, cardiologists with expertise in CHD and obstetric anesthesia.

Successful fibrinolytic treatment of prosthetic heart valve thrombosis using streptokinase

OBJECTIVES

This study aims to evaluate the clinical outcome of fibrinolytic treatment of prosthetic valve thrombosis (PVT) with 'streptokinase' as a first line treatment for these cases.

METHODS

The study group was 20 consecutive patients (10 females) diagnosed with PVT. The protocol for streptokinase administration was either accelerated (intravenous infusion of 0.5 million IU over 30 minutes followed by 0.15 million IU/h) or conventional (intravenous infusion of 0.25 million IU over 30 minutes followed by 0.15 million IU/h). Success of fibrinolytic therapy was defined as complete restoration of valve function in the presence or absence of complications.

RESULTS

Eighteen patients (90%) had mitral PVT and two (10%) had aortic PVT. Thrombolytic therapy with streptokinase was successful in all but one case, with a total mortality of four cases (20%). In PVT episodes, before streptokinase therapy, the prosthetic valve areas (in all cases, mitral and aortic positions) were 0.82 ± 0.21, 0.83 ± 0.21, and 0.73 ± 0.18 cm²; and the peak and mean transvalvular gradients were 38.7 ± 16.7 and 25.4 ± 8.7, 34.1 ± 8.8 and 23.2 ± 5.4, and 80.0 ± 14.1 and 45.0 ± 7.1 mmHg, respectively. After streptokinase therapy, the prosthetic valve area and peak and mean transvalvular gradients improved significantly (for all cases, mitral and aortic positions: valve area 2.17 ± 0.58, 2.21 ± 0.61, and 1.85 ± 0.07 cm², peak gradient 18.7 ± 11.0, 16.4 ± 7.7, and 39.0 ± 18.4, and mean gradient 9.6 ± 7.1, 8.2 ± 5.3, and 22.0 ± 11.3 mmHg, respectively; paired t-test, P<0.001 for pre- versus post-streptokinase infusion for all variables).

CONCLUSION

Fibrinolytic therapy using streptokinase was an effective therapeutic strategy for the management of PVT and is a reasonable alternative to surgery.