Pearls – mechanical valve thrombosis

1. The hypercoagulable state of pregnancy presents a risk for women with mechanical heart valves with contemporary data estimating the rate of valve thrombosis during pregnancy at around 5%.
2. Thrombolytic therapy is a (relatively) safe alternative to surgery and should be considered first line for treatment of prosthetic valve thrombosis in all patients, especially in pregnant women.
3. Pre-conception counselling and meticulous anticoagulation management for patients with mechanical heart valves are key aspects of their care.
4. The evaluation for prosthetic valve thrombosis in pregnant persons requires a review of anti-coagulation history and careful choice of diagnostic testing to confirm the diagnosis and minimize risks to the parent and the baby.
5. Multi-disciplinary care with close collaboration between cardiology and obstetrics is critical when caring for pregnant persons with cardiac disease.

Show Notes – mechanical valve thrombosis

How can we counsel and inform women with heart disease who are contemplating pregnancy?

• Use the Modified World Health Organization classification of maternal cardiovascular risk to counsel patients on their maternal cardiac event rate and recommended follow-up visits and location of delivery (local or expert care) if pregnancy is pursued.
• To learn about normal pregnancy cardiovascular physiology and pregnancy risk stratification in persons with cardiovascular disease, enjoy CardioNerds Episode #111. Cardio-Obstetrics: Normal Pregnancy Physiology with Dr. Garima Sharma.

Adapted from the 2018 ESC Guidelines for the management of cardiovascular diseases during pregnancy

What is the differential diagnosis for a new murmur in a pregnant person who has undergone heart valve replacement?

1. Normal physiology – elevated flow from hyperdynamic state and/or expansion of blood volume in pregnancy.
   1. Pathologic – increased left ventricular outflow tract flow from turbulence of flow due to pannus ingrowth, new paravalvular leak, or obstructive mechanical disk motion from vegetation or thrombus.

What are diagnostic modalities for the evaluation of suspected prosthetic valve thrombosis?

• The 2020 ACC/AHA guidelines gave a class I recommendation for evaluation of suspected mechanical prosthetic valve thrombosis using transthoracic echocardiogram, transesophageal echocardiogram (TEE), fluoroscopy, and/or multidetector computer tomography.
• The goals multi-modality imaging are to assess valve function, leaflet motion, and presence and extent of thrombus while weighing the risks, benefits, and limitations of each modality.
• The hemodynamic effects with sedation required for TEE and radiation involved with each modality should be carefully assessed when choosing what modalities to pursue, particularly with regards to both parent and baby health.

What are the treatment options for prosthetic valve thrombosis in pregnant patients?

• The 2020 ACC/AHA guidelines gave a class I recommendation for treatment options using slow-infusion, low-dose fibrinolytic therapy or undergoing emergency surgery.
• Cardiac surgeries during pregnancy are associated with high rates of maternal and fetal adverse outcomes; therefore, a slow-infusion, low-dose fibrinolytic therapy is an attractive alternative option in hemodynamically stable patients.

What are the anticoagulation and antiplatelet strategies for pregnant patients with mechanical heart valves?

• All patients should be on aspirin 81mg daily unless they have active bleeding contraindications.
• No anticoagulation strategy has been proven to be superior for both the parent and the fetus.
• If low molecular weight heparin is used, strict monitoring of anti-Xa levels is recommended to optimize anticoagulation and prevent complications.
• Warfarin can be used throughout pregnancy if the therapeutic doses is ≤5 mg/day to reduce the risk of fetal toxicity. Warfarin teratogenicity is highest during the first trimester. However, after the 36th week patients require admission for transition to heparin to minimize risk of fetal intracranial hemorrhage and maternal bleeding during delivery.
• To learn more about anticoagulation during pregnancy, enjoy CardioNerds Episode #163. Cardio-Obstetrics: Pregnancy and Anticoagulation with Dr. Katie Berlacher.

References

1. Van HI, Roos-Hesselink JW, Ruys TPE, Merz WM, Goland S, Gabriel H, et al. Pregnancy in women with a mechanical heart valve. Circulation 2015;132:132–142.
2. Özkan M, Gündüz S, Gürsoy OM, Karakoyun S, Astarcioʇlu MA, Kalçik M, et al. Ultraslow thrombolytic therapy: a novel strategy in the management of PROsthetic MEchanical valve Thrombosis and the prEdictors of outcomE: the ultra-slow PROMETEE trial. Am Heart J 2015;170:409–418.e1. 5.
3. Otto CM, Nishimura RA, Bonow RO, Carabello BA, Erwin JP, Gentile F, et al. 2020 ACC/AHA guideline for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association Joint Committee on clinical practice guidelines. Circulation 2021;143:e35–e71.
4. Vahanian A, Beyersdorf F, Praz F, Milojevic M, Baldus S, Bauersachs J, et al. 2021 ESC/ EACTS guidelines for the management of valvular heart disease: developed by the task force for the management of valvular heart disease of the European Society of Cardiology (ESC) and the European Association for Cardio-Thoracic Surgery (EACTS). Eur Heart J. 2022;43:561–632.
5. Özkan M, Gündüz S, Biteker M, Astarcioglu MA, Çevik C, Kaynak E, et al. Comparison of different TEE-guided thrombolytic regimens for prosthetic valve thrombosis: the TROIA trial. JACC Cardiovasc Imaging 2013;6:206–216.
6. Özkan M, Çakal B, Karakoyun S, Gürsoy OM, Çevik C, Kalçik M, et al. Thrombolytic therapy for the treatment of prosthetic heart valve thrombosis in pregnancy with lowdose, slow infusion of tissue-type plasminogen activator. Circulation 2013;128:532–540.
7. Regitz-Zagrosek V, Roos-Hesselink JW, Bauersachs J, Blomström-Lundqvist C, Cífková R, De BM, et al. 2018 ESC guidelines for the management of cardiovascular diseases during pregnancy. Eur Heart J 2018;39:3165–3241.
8. D’Souza R, Ostro J, Shah PS, Silversides CK, Malinowski A, Murphy KE, et al. Anticoagulation for pregnant women with mechanical heart valves: a systematic review and meta-analysis. Eur Heart J 2017;38:1509–1516.