///2017 Abstract Details
2017 Abstract Details2019-08-02T15:54:53-06:00

Thrombosed mechanical heart valves requiring emergent cesarean delivery and extracorporeal membranous oxygenation

Abstract Number: SUN-36
Abstract Type: Case Report/Case Series

Michael D Wu MD, PhD1 ; Atisa Britton MD2; Jessica Tashjian MD3; Pedram Aleshi MD4

Mechanical heart valves in pregnancy are associated with significant complications for the mother and fetus. Warfarin provides more reliable anticoagulation but is associated with high rates of fetal loss and embryopathy. LMWHs have a lower risk of fetal teratogenicity but are difficult to dose given changing pharmacokinetics throughout pregnancy. The risk of thrombosed mechanical heart valves should be considered in pregnant patients even on anticoagulation.

We present a 35 year old G3P2 at 28 weeks gestation with a history of rheumatic fever who previously had mechanical mitral and aortic valve replacement in 2008 that presented for worsening shortness of breath. She had been transitioned during her pregnancy from warfarin 5 mg PO daily to enoxaparin 60 mg SQ every 12 hours during her pregnancy for anticoagulation but admitted to being off anticoagulation for 1 week approximately six weeks prior to her presentation. Labs and imaging were consistent with acute congestive heart failure. TTE showed elevated mitral and aortic valve gradients, pulmonary hypertension, and global hypokinesis. She quickly decompensated requiring bi-level ventilation and vasopressors.

Because of her tenuous cardiopulmonary status, she was brought to the OR where the cardiothoracic surgery team placed femoral cannulas for urgent V-A ECMO if needed. After appropriate central and arterial access, she underwent a RSI with intubation using a Glidescope with pink frothy sputum noted. TEE evaluation was limited by valve artifact but did show EF 20-25% with severely restricted motion of the aortic valve leaflets. She underwent a cesarean delivery and then became more hypotensive despite vasopressor support and was subsequently placed on ECMO.

In order to visualize the valves better, a cardiac catheterization occurred on PPD 1 that confirmed a normal functioning mechanical mitral valve but fixed aortic valve leaflets. On PPD 2, she underwent an open AVR on CPB, mitral valve thrombectomy, and ECMO decannulation.

Discussion

This case highlights the challenges of mechanical heart valves in pregnancy and the requirement to have delivery of the fetus at an institution capable of ECMO given the risk of worsening cardiac function of the mother. It also draws attention to the need for a multidisciplinary approach to managing anticoagulation in patients with mechanical heart valves early in the pregnancy given the risks to both mother and fetus. The ACC/AHA guidelines suggest continuing low dose warfarin throughout pregnancy given the lower risk of thromboembolic complications as well as the difficulty dosing LMWH, however, this has to be weighed against the possibility of fetal loss.

References:

1. Alshawabkeh et al. J Am Coll Cardiol. 2016. Oct;68(16):1804-1813.

2. Halldorsdottir et al. Int J Obstet Anesth. 2016. May;26:75-8.

SOAP 2017