Cath Lab Digest

Evolving clinical conundrums in modern cardiology require insights from many sources. In this spirit, I’d like to present another ‘conversation in cardiology’ about a real dilemma involving a woman, a stent, and dual anti-platelet therapy. My colleagues generously contributed their thoughtful opinions to assist the treating physician in his decision-making. The conversation addresses the pros and cons, and puts the issue into perspective for a best clinical decision. Let’s see what happened

[Disclaimer:  The opinions expressed below are those of the authors of the comments. These opinions are not intended to be used as authoritative sources, which may be obtained from standard reference literature regarding the problem.]

The Clinical Problem

A referring cardiologist called me today. His patient, a 40-year-old female, had a 2.75 mm/28 mm Promus stent placed in her mid-left anterior descending artery (LAD) 5 months ago. She presented to him today, stating that she is 5 weeks pregnant. What would you do about her dual anti-platelet therapy (DAPT)?

Anna Kalynych
Carleton, Georgia

From Chicago:
Aspirin is a class D agent for pregnancy. The baby may already have sustained teratogenic effects. After 32 weeks, the prostaglandin effect could lead to placenta blood flow abnormalities and failure to close the ductus. The FDA has a warning in the last trimester.

Clopidogrel (Plavix) is listed as class B in pregnancy. Hence, there is probably a low risk of teratogenicity. There is limited experience with its use, however. There may be increased bleeding relating to delivery or a c-section. Since it is not a prostaglandin inhibitor, those concerns are not operative. I would work closely with an obstetrician in this case. Given that the stent is 5 months old and the mother in the first trimester, for the last trimester, I would probably lean toward stopping the aspirin and going with 150mg clopidogrel. Until then, and for the next 7 months, the FDA warning provides a judgment call in regard to risk vs. benefit. Perhaps a low dose of aspirin could be given until that time. Too bad a bare metal stent was not placed — that would have been so much easier!

Lloyd W. Klein

From Duke University:
This is definitely a conundrum.  Aspirin (ASA) is relatively contraindicated in pregnancy.  At high doses in animal models it is teratogenic.  In humans, aspirin can cause abnormal closure of the ductus, and therefore should not be given in the last trimester.  It can cause problems with hemostasis at the time of delivery. The good news is that low-dose ASA has been explicitly tested in tens of thousands of pregnant women in formal clinical trials, so there actually is a body of data about ASA and pregnancy.

Much less is known about clopidogrel. The package insert lists it as a Class B pregnancy risk (I looked it up), which basically means that nobody knows, because it hasn’t been studied. There isn’t even enough known about clopidogrel to determine whether it is teratogenic. 

So here’s my thoughts — a discussion should occur with the mother and father to determine the psychosocial aspects related to this pregnancy — how many children she has borne, what their mindset is about this pregnancy, etc. She needs to be counseled about the risks (including mortality) to both her and her child. The stent that was implanted is long and small, not a great device to leave relatively unprotected. If it helps in our thinking about management, the date of delivery should be around the 1-year anniversary following the stent implantation. The hemodynamic stresses of pregnancy and delivery can be quite scary. I would think that a spontaneous vaginal delivery would be out. I’d be very worried about spontaneous coronary dissection in the last trimester or just after delivery. If she makes it through the pregnancy and wants to breast feed, she’ll need to consider that at least she’ll be put back on ASA after delivery and this is associated with child developmental issues. In summary, there are both cardiac and obstetrical risks to consider, including a relatively high potential for serious morbidity and mortality (both mother and baby).

Management options: This is collectively in the unacceptable risk category, so termination of the pregnancy should be recommended as the first choice. If termination of the pregnancy is not an option, then the situation becomes much more difficult. The usual DAPT question is “when to stop the clopidogrel.” But I would think about stopping the aspirin instead — perhaps even now — leaving her on clopidogrel only. She is 5 months out from stent implantation, so now is as good time as any to stop the ASA. I would keep the clopidogrel going up to 3-4 days before a scheduled c-section, and then restart ASA just after delivery.  And I would make sure that I have documented all discussions with her, and have my malpractice insurance paid up.
Jimmy Tcheng

From Boston: 
This is a great response, Jimmy...no surprise to anyone that your comments are so insightful.  Couple of questions/points: