Risks and pregnancy outcome in women with prosthetic mechanical heart valve replacement

Pregnancy managed by unfractionated heparin after mechanical aortic valve replacement

Pregnancy after mechanical valve replacement involves high risk. Maternal valve thrombosis and hemorrhagic complications are associated with lethal outcomes; therefore, strict anticoagulant therapy is needed. Our patient was 26-year-old primiparous woman. She had undergone aortic valve replacement with a mechanical valve at 4 years of age and had used warfarin 3 mg per day since then. Because of her desire for a baby, she stopped warfarin and conceived spontaneously. She was referred to our hospital. After being informed of her choices, unfractionated heparin (UFH) administration was started. She experienced mild heart failure with sacroiliitis, bacteremia, and hematuria during pregnancy. She delivered her newborn at 37 weeks. Blood loss at delivery was 220 g. Administration of UFH was restarted 4 h after delivery and 3 mg of warfarin was administered from postpartum day (PPD) 6. Hemostatic suturing was required for vaginal bleeding on PPD7. A therapeutic dose of warfarin was achieved on PPD9. Although warfarin use is recommended as anticoagulant therapy for pregnant woman with mechanical valves, the safety and efficacy of UFH have not yet been clarified because of its limited use. More cases are needed to clarify this.

Maternal and Fetal Outcomes of Anticoagulation in Pregnant Women With Mechanical Heart Valves

Background

Anticoagulation for mechanical heart valves during pregnancy is essential to prevent thromboembolic events. Each regimen has drawbacks with regard to maternal or fetal risk.

Objectives

This meta-analysis sought to estimate and compare the risk of adverse maternal and fetal outcomes in pregnant women with mechanical heart valves who received different methods of anticoagulation.

Methods

Studies were identified using a Medline search including all publications up to June 5, 2016. Study inclusion required reporting of maternal death, thromboembolism, and valve failure, and/or fetal spontaneous abortion, death, and congenital defects in pregnant women treated with any of the following: 1) a vitamin K antagonist (VKA) throughout pregnancy; 2) low-molecular-weight heparin (LMWH) throughout pregnancy; 3) LMWH for the first trimester, followed by a VKA (LMWH and VKA); or 4) unfractionated heparin for the first trimester, followed by a VKA (UFH and VKA).

Results

A total of 800 pregnancies from 18 publications were included. Composite maternal risk was lowest with VKA (5%), compared with LMWH (16%; ratio of averaged risk [RAR]: 3.2; 95% confidence interval [CI]: 1.5 to 7.5), LMWH and VKA (16%; RAR: 3.1; 95% CI: 1.2 to 7.5), or UFH and VKA (16%; RAR: 3.1; 95% CI: 1.5 to 7.1). Composite fetal risk was lowest with LMWH (13%; RAR: 0.3; 95% CI: 0.1 to 0.8), compared with VKA (39%), LMWH and VKA (23%), or UFH and VKA (34%). No significant difference in fetal risk was observed between women taking ≤5 mg daily warfarin and those with an LMWH regimen (RAR: 0.9; 95% CI: 0.3 to 2.4).

Conclusions

VKA treatment was associated with the lowest risk of adverse maternal outcomes, whereas the use of LMWH throughout pregnancy was associated with the lowest risk of adverse fetal outcomes. Fetal risk was similar between women taking ≤5 mg warfarin daily and women treated with LMWH.

Outcomes of prosthetic valve replacement in women of child-bearing age

PURPOSE

The outcomes of pregnancy are more favorable for women with bioprostheses than for those with mechanical prostheses. However, bioprostheses are associated with a high reoperation rate in young women and it remains unclear whether these young women can give birth without any complications. We analyzed the outcomes of prosthetic valve replacement and investigated the effectiveness and problems associated with bioprostheses in women of child-bearing age in Japan.

METHODS

The subjects of this study were six consecutive young adult women aged under 40 years, who underwent prosthetic valve replacement between January 2007 and April 2016.

RESULTS

Bioprostheses were selected for four of these six women in consideration of their child-bearing age. Mechanical valves were selected for the other two women who underwent the Konno procedure and double valve replacement (AVR, MVR) in view of their high risk for reoperation. The cardiac operations, although without mortality or morbidity, were complex and some involved multi-time procedures. Three of the women with bioprostheses had uneventful term pregnancies.

CONCLUSIONS

These young women with bioprostheses were able to give birth safely; however, as multiple operations are often required, and bioprostheses may not be ideal for young women. Prosthetic valve selection for young women of child-bearing age requires adequate pregnancy counseling and long-term planning.

Pregnancy Outcome in Women with Mechanical Prosthetic Heart Valves Treated with Unfractionated Heparin (UFH) or Enoxaparin

OBJECTIVE

This study was carried out to determine the maternal (including thromboembolic and hemorrhagic complications) and fetal outcomes (including miscarriage, stillbirth, baby death, and live birth) in women with mechanical heart valves managed with therapeutic doses of unfractionated heparin (UFH) versus enoxaparin during pregnancy.

METHODS

This is a prospective comparative, nonrandomized study. Pregnant women with mechanical heart valves presenting to high-risk pregnancy unit of Benha University Hospital, Egypt were treated with UFH 15,000 U/12 h versus enoxaparin (Clexane) 1 mg/kg SC/12 h during pregnancy and the results were analyzed.

RESULTS

40 pregnant women were included in the study. In 20 pregnant women, anticoagulation was with UFH, and 20 pregnant women received enoxaparin. One (3 %) thrombotic complication occurred with enoxaparin treatment. Noncompliance or subtherapeutic levels contributed to this outcome in this case. Antenatal hemorrhage occurred in 4 (10 %) and postpartum hemorrhagic complications in 5 (12.5 %) pregnancies. Of the 32 pregnant women who continued after 20 weeks' gestation, 100 % (17/17) of the women taking predominantly UFH had a surviving infant compared with 93 % (14/15) of the women taking primarily enoxaparin (p = 0.25). One intrauterine fetal death occurred in the enoxaparin group. There was no significant difference in the live birth rates between the two groups (p = 0.31).

CONCLUSIONS

Compliance with therapeutic dose of UFH during pregnancy in women with mechanical heart valves is associated with a low risk of valve thrombosis and good fetal outcomes, but meticulous monitoring is essential.

Impact of Ross Operation on Outcome in Young Female Adult Patients Wanting to Have Children

BACKGROUND

The most appropriate valve substitute at aortic valve replacement (AVR) for young female adult patients wanting to have children is unclear.

METHODS AND RESULTS

Between 1992 and 2013, 12 consecutive female patients aged >18 (median, 22.5 years; range, 18-34 years) underwent Ross operation (Ross group). Between 1984 and 2013, 9 consecutive female patients aged >18 (median, 30 years; range, 22-39 years) underwent AVR with bioprosthesis (bioprosthesis group). There was 1 late mortality in the bioprosthesis group, due to prosthetic valve endocarditis (PVE). Freedom from reoperation for aortic valve at 15 years was 90.0% in the Ross group, and 57.1% in the bioprosthesis group (log-rank, P=0.098). One in the Ross group underwent reoperation for aortic regurgitation (AR), whereas 4 in the bioprosthesis group did so for aortic stenosis (AS) in 2, combined AS and AR in 1, and PVE in 1. Five patients in the Ross group and 3 in the bioprosthesis group had 7 and 4 uneventful pregnancies, respectively. AR progressed during the perinatal period in a total of 7 of 11 pregnancies. No AS was seen at discharge, after 5 years, or during pregnancy in the Ross group.

CONCLUSIONS

The long-term outcome of Ross operation for female patients wanting to have children is excellent. Although subclinical pulmonary autograft valve regurgitation during pregnancy was often observed, pulmonary autograft stenosis did not occur, therefore it would be an ideal option for patients wanting to have children.

[Pulse contour analysis calibrated by Trans-pulmonar thermodilution (Picco Plus(®)) for the perioperative management of a caesarean section in a patient with severe cardiomyopathy]

BACKGROUND

The delivery of cardiac patients is a challenge for the anaesthesiologist, to whom the welfare of both the mother and the foetus is a main issue. In case of caesarean section, advanced monitoring allows to optimize haemodynamic condition and to improve morbidity and mortality.

OBJECTIVE

To describe the use of pulse contour analysis calibrated by Trans-pulmonar thermodilution (Picco Plus(®)) for the perioperative management of a caesarean section in a patient with severe cardiomyopathy.

CASE REPORT

We describe the case of a 28-year-old woman with a congenital heart disease who was submitted to a caesarean section under general anaesthesia for maternal pathology and foetal breech presentation. Intra- and post-operative management was optimized by advanced haemodynamic monitorization obtained by pulse contour wave analysis and thermodilution calibration (Picco Plus(®) monitor). The information about preload, myocardial contractility and postcharge was useful in guiding the fluid therapy and the use of vasoactive drugs.

CONCLUSION

This case report illustrates the importance of advanced haemodynamic monitoring with an acceptably invasive device in obstetric patients with high cardiac risk. The increasing experience in advanced haemodynamic management will probably permit to decrease morbidity and mortality of obstetric patients in the future.

Monitoring of Anti-Xa in Pregnant Patients With Mechanical Prosthetic Valves Receiving Low-Molecular-Weight Heparin

Objectives:

We hypothesized that the guideline-recommended peak anti-Xa levels for pregnant women with mechanical prosthetic heart valves (MPHVs) receiving adjusted dose low-molecular-weight heparin (LMWH) are associated with subtherapeutic trough levels and consequently with an inadequate level of anticoagulation.

Background:

Low-molecular-weight heparin is often used for anticoagulation in pregnant women including those with MPHV. American College of Cardiology/American Heart Association guidelines recommend monitoring of plasma anti-Xa factor peak levels and adjustment of the dose to achieve peak levels of 0.7 to 1.2 U/mL. In spite of these recommendations, cases of valve thrombosis during pregnancy continue to occur.

Methods and Results:

We studied 30 pregnant patients receiving anticoagulation for various indications with adjusted dose LMWH given subcutaneously twice a day which had both trough and peak anti-Xa levels throughout pregnancy for a total of 187 paired determinations. The recommended peak anti-Xa levels (0.7-1.2 U/mL) were obtained in 123 (66%) of the measurements but in 80% of them, the trough levels were found to be subtherapeutic (<0.6 U/mL). Subtherapeutic trough levels were found in 8 (73%) of the 11 measurements with peak levels of 0.7 to 0.79 U/mL, 17 (74%) of the 23 of 0.8 to 0.89 U/mL, 21 (72%) of the 29 of 0.9 to 0.99 U/mL, and 28 (44%) of the 63 of 1.0 to 1.2 U/mL. There were 42 measurements with peak anti-Xa levels >1.2 U/mL and even in these cases, 13 (31%) of the trough levels were found to be subtherapeutic.

Conclusions:

Anticoagulation with adjusted dose LMWH aimed to achieve guideline-recommended peak levels of anti-Xa for patients with MPHVs is commonly associated with subtherapeutic trough levels. Routine measurement of trough anti-Xa levels is therefore advisable in women with MPHV treated with LMWH during pregnancy to assure adequate level of anticoagulation.

Pulse contour analysis calibrated by Trans-pulmonar thermodilution (Picco Plus(®)) for the perioperative management of a caesarean section in a patient with severe cardiomyopathy

BACKGROUND

The delivery of cardiac patients is a challenge for the anaesthesiologist, to whom the welfare of both the mother and the foetus is a main issue. In case of caesarean section, advanced monitoring allows to optimize haemodynamic condition and to improve morbidity and mortality.

OBJECTIVE

To describe the use of pulse contour analysis calibrated by Trans-pulmonar thermodilution (Picco Plus(®)) for the perioperative management of a caesarean section in a patient with severe cardiomyopathy.

CASE REPORT

We describe the case of a 28-year-old woman with a congenital heart disease who was submitted to a caesarean section under general anaesthesia for maternal pathology and foetal breech presentation. Intra- and post-operative management was optimized by advanced haemodynamic monitorization obtained by pulse contour wave analysis and thermodilution calibration (Picco Plus(®) monitor). The information about preload, myocardial contractility and postcharge was useful in guiding the fluid therapy and the use of vasoactive drugs.

CONCLUSION

This case report illustrates the importance of advanced haemodynamic monitoring with an acceptably invasive device in obstetric patients with high cardiac risk. The increasing experience in advanced haemodynamic management will probably permit to decrease morbidity and mortality of obstetric patients in the future.

VTE, thrombophilia, antithrombotic therapy, and pregnancy: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines

BACKGROUND

The use of anticoagulant therapy during pregnancy is challenging because of the potential for both fetal and maternal complications. This guideline focuses on the management of VTE and thrombophilia as well as the use of antithrombotic agents during pregnancy.

METHODS

The methods of this guideline follow the Methodology for the Development of Antithrombotic Therapy and Prevention of Thrombosis Guidelines: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines in this supplement.

RESULTS

We recommend low-molecular-weight heparin for the prevention and treatment of VTE in pregnant women instead of unfractionated heparin (Grade 1B). For pregnant women with acute VTE, we suggest that anticoagulants be continued for at least 6 weeks postpartum (for a minimum duration of therapy of 3 months) compared with shorter durations of treatment (Grade 2C). For women who fulfill the laboratory criteria for antiphospholipid antibody (APLA) syndrome and meet the clinical APLA criteria based on a history of three or more pregnancy losses, we recommend antepartum administration of prophylactic or intermediate-dose unfractionated heparin or prophylactic low-molecular-weight heparin combined with low-dose aspirin (75-100 mg/d) over no treatment (Grade 1B). For women with inherited thrombophilia and a history of pregnancy complications, we suggest not to use antithrombotic prophylaxis (Grade 2C). For women with two or more miscarriages but without APLA or thrombophilia, we recommend against antithrombotic prophylaxis (Grade 1B).

CONCLUSIONS

Most recommendations in this guideline are based on observational studies and extrapolation from other populations. There is an urgent need for appropriately designed studies in this population.

Premeditated reoperation after mitral valve replacement with a Starr-Edwards ball valve for young women who desire to bear a child: report of two cases

There are many difficulties for young women with a Starr-Edwards ball valve who want to attempt pregnancy. There is no consensus regarding whether they should maintain anticoagulation therapy throughout pregnancy with the risk of a thromboembolism or to undergo a reoperation with bioprosthetic heart valves, followed by a third operation when the valve deteriorates. This report presents two cases of young women who underwent mitral valve replacement (MVR) with Starr-Edwards ball valves (model 6120: 1M) during their childhood. Although they did not have any cardiac symptoms, transthoracic echocardiography and cardiac catheterization data demonstrated that both the patients had asymptomatic mild relative mitral stenosis. They both wished to bear a child. After the patients and their family provided thorough informed consent, redo MVRs were preformed safely with biological prostheses. The presence of significant pannus formation along the strut and sewing ring of the excised valves could also have a positive impact on the decision to undergo reoperation.

Reducing stillbirths: prevention and management of medical disorders and infections during pregnancy

BACKGROUND

An estimated two-thirds of the world's 3.2 million stillbirths occur antenatally, prior to labour, and are often overlooked in policy and programs. Poorly recognised, untreated or inadequately treated maternal infections such as syphilis and malaria, and maternal conditions including hypertensive disorders, are known risk factors for stillbirth.

METHODS

We undertook a systematic review of the evidence for 16 antenatal interventions with the potential to prevent stillbirths. We searched a range of sources including PubMed and the Cochrane Library. For interventions with prior Cochrane reviews, we conducted additional meta-analyses including eligible newer randomised controlled trials following the Cochrane protocol. We focused on interventions deliverable at the community level in low-/middle-income countries, where the burden of stillbirths is greatest.

RESULTS

Few of the studies we included reported stillbirth as an outcome; most that did were underpowered to assess this outcome. While Cochrane reviews or meta-analyses were available for many interventions, few focused on stillbirth or perinatal mortality as outcomes, and evidence was frequently conflicting. Several interventions showed clear evidence of impact on stillbirths, including heparin therapy for certain maternal indications; syphilis screening and treatment; and insecticide-treated bed nets for prevention of malaria. Other interventions, such as management of obstetric intrahepatic cholestasis, maternal anti-helminthic treatment, and intermittent preventive treatment of malaria, showed promising impact on stillbirth rates but require confirmatory studies. Several interventions reduced known risk factors for stillbirth (e.g., anti-hypertensive drugs for chronic hypertension), yet failed to show statistically significant impact on stillbirth or perinatal mortality rates. Periodontal disease emerged as a clear risk factor for stillbirth but no interventions have reduced stillbirth rates.

CONCLUSION

Evidence for some newly recognised risk factors for stillbirth, including periodontal disease, suggests the need for large, appropriately designed randomised trials to test whether intervention can minimise these risks and prevent stillbirths. Existing evidence strongly supports infection control measures, including syphilis screening and treatment and malaria prophylaxis in endemic areas, for preventing antepartum stillbirths. These interventions should be incorporated into antenatal care programs based on attributable risks and burden of disease.