///2015 Abstract Details
2015 Abstract Details2019-08-02T16:54:43-06:00

• Management of Parturient with Prosthetic Aortic Valve: Prosthesis Patient Mismatch vs. Graft Stenosis

Abstract Number: T-46
Abstract Type: Case Report/Case Series

Mahesh Vaidyanathan MD, MBA1 ; Pankaj Jain MD2

Aortic Stenosis (AS) in pregnancy represents a life threatening medical condition as it may result in maternal death and/or poor fetal outcomes. Traditionally, patients of childbearing age were treated with metallic prosthetic valves because they offered better hemodynamics and a longer lifespan than bio-prosthetic valves. Unfortunately, anticoagulants required for metallic valves are teratogenic.

Newer bio-prosthetic valves have better hemodynamics, a longer lifespan, and do not require anticoagulants. Overtime, the patient will require valve replacement but it does provide for a safer pregnancy. Importantly, the flow through prosthetic valves can appear stenotic during pregnancy though it is functioning well. This phenomenon is known as Prosthesis Patient Mismatch (PPM).

We present a 23 YO G2P1001 F with IUP at 39wks with prenatal dx of post valve replacement severe AS. Initial TEE at 33 wks showed AVA 0.8 with LVH. Porcine aortic valve replacement was done 7 years prior due to S. Bovi endocarditis. Obstetric plan was assisted vaginal delivery via induction of labor at 39 wks. TEE was repeated at 38 wks and showed EF 67% with AVA of 0.7 and systolic peak and mean gradients of 80 and 48 mmhg, respectively without LVH. At admission, physical exam revealed no symptoms related to severe AS. We determined the elevated gradients were likely due to PPM, given that the patient's body surface area (BSA) and cardiac output (CO) had increased due to pregnancy. The patient was well compensated. We gave a fluid bolus to ensure preload, placed an epidural, a 10cc bolus of 0.1% Ropivicaine with 2mcg/ml Fentanyl was administered, and the infusion was started at the rate of 10 ml/hr. Adequate labor analgesia was established. Labor progressed appropriately with stable blood pressures. Vaginal delivery with the assistance of forceps was achieved.

The risk of pregnancy is low in women with no or minimal AS and uncompromised ventricular function.[1] However, in patients with severe AS, medical treatment and indications for intervention are comparable with those for pregnancies with native valve AS. Patients, who are asymptomatic, even with severe AS, with normal LV size and function should be treated as low risk.[1] Additionally, when ECHO evaluations appear to show severe AS in asymptomatic patients, PPM should be considered. High velocity or gradient alone is not proof of intrinsic prosthetic obstruction and may be secondary to PPM or high flow state.[2] PPM occurs when the effective orifice area(EOA) of a normally functioning prosthesis is too small in relation to the patient’s BSA or CO requirements. [2] Our patient’s BSA increased and pregnancy is a high CO state. Both of these factors affected the initial ECHO values. Our diagnosis of intra-partum PPM was corroborated by repeat ECHO 2 month’s post-partum. BSA and CO decreased, resulting in peak and mean gradients consistent with mild AS.

1. European Heart Journal 2011;32:3147–3197

2. Heart 2012;98:69-78

SOAP 2015