We'll move on to our next speaker. We'll introduce, this is Dr. Michelle Volz. She's a board certified physician in internal medicine, cardiology, and interventional cardiology, the Northside Hospital Cardiovascular Institute, and she will be speaking on the management of pregnant women in cath lab and how to mitigate fetal risk. Dr. Volz, thank you so much. Thank you, Dr. Park, and thank you also, Dr. Portman, for that excellent introduction. Some of the things that you briefly touched on, I'm going to go a little bit more in depth into. These are my disclosures. None of these will be relevant to the things we're talking about tonight. So pregnant women in the cath lab. So she's coming to the cath lab. What do we do? There are a number of conditions in pregnancy that may require coronary angiography, myocardial infarction, cardiogenic shock, particularly requiring device placement, pulmonary embolus, which happens to be one of my areas of interest, and mechanical valvular disease requiring valvetin A or fluoro. There are a number of others that are less common, but these are really the big ones. And I'm not going to go over the next slide because I think we're going to talk about it a little bit more, but if you'll look over here at the illustration, you'll see that there are multiple causes of acute MI in pregnancy, including, but not limited to coronary disease, which is getting more and more common as our pregnant population ages with time, coronary embolism, vasospasm, and of course, SCAD. Why don't pregnant women make it to the cath lab? Although acute MI is rare in young women, pregnancy actually increases the risk of acute MI three to four-fold over age-matched controls, and anterior STEMIs are actually the most common type. One study of 859 patients with acute MI during pregnancy and during the postpartum period, of those only 45% underwent cardiac catheterization. And there are multiple reasons for this, including a lack of timely and appropriate diagnosis, a reluctance to intervene once the diagnosis is made, and of course, as always, bias probably plays a role in the diagnosis of treatment in this vulnerable population. PCI remains the standard of care for the management of STEMI and non-STEMI in pregnant women, and I can't say that enough. So first, let's talk about the medications that we use in the cath lab. So I was in the lab the other day, and one of the vascular surgeons happened to have been called about a pregnant woman with a PE. She was eight weeks along, and I was walking by the control room when I heard screaming. And so I'm nosy, and so I stuck my head in the control room, and I said, hey, you guys okay in here? Oh, yes, this woman's pregnant, and she has a pulmonary embolism, and she's having a mechanical thromboembolectomy. I said, well, did she get sedation? Oh, no, we can't give her any sedation because she's pregnant. I said, oh, geez. So of course, I put my cardio obstetrics hat on and went into the room. So sedation, Versed, Fentanyl, Dilaudid, whatever you use in your lab, they are safe for use in pregnancy. The only time you have to use caution is if delivery is imminent, and that's because they can have a sedative effect on baby as well. And even then, babies can be resuscitated. We can assist them with their breathing if they're born sleepy. So please, please, please sedate this woman like the poor nine-week pregnant patient who was having a 26 front sheath placed in her groin. Antiplatelet therapy. Aspirin is safe in pregnancy and should be used when indicated. Glycoprotein 2b3a inhibitors. They have not been well studied, but they should be used if they're strongly indicated. So if you are doing a STEMI, and you have a side branch closure, you have no reflow, and you feel like you need a glycoprotein inhibitor, you should not hesitate to use one in a pregnant woman. P2Y12 inhibitors. We have limited data. There's no clear evidence of fetal harm, but they're not well studied. But obviously, our post-STEMI patients who are pregnant are treated with DAPT. Looking at anticoagulants, heparin is usually our choice because it's acceptable in pregnant and postpartum women, also because it can be turned on and turned off quickly. It can be started within six to 12 hours of a vaginal delivery and 12 to 24 hours after a C-section. But frankly, just a couple of months ago, we did a C-section on a young lady who was on ECMO for COVID infection, and we took her baby in the CCU on an ECMO circuit at 28 weeks, and she got heparin, and we dealt with the bleeding. DOACs. We generally don't use these in pregnancy, but particularly not in women who are breastfeeding. And direct thrombin inhibitors. Argatroban actually has class B safety in pregnancy. There's little human data for bivalorudin, but we don't believe that there's any significant harm to the fetus. What about if the patient goes bad? What do you do for support? So with regard to vasopressors, phenylephrine is actually your presser of choice in pregnancy. It's a pure alpha agonist, but despite the alpha activity, it doesn't have much effect on fetal blood flow at low and moderate doses. And so this is actually a very good presser for use in pregnancy. Epinephrine is not great for use in pregnancy. It's got a significant reduction in uteroplacental blood flow, even more so than norepinephrine. And it's really only acceptable for short-term use, like anaphylaxis or codes. You should pick another presser if you're going to need something in the longer term. Norepinephrine is an excellent alternative. It does, however, reduce uteroplacental blood flow. So if we went in order, vasopressin has the least, or excuse me, phenylephrine has the least reduction, followed by norepinephrine, followed by epinephrine, which has the greatest reduction. Vasopressin, we have very little data on uterine flow, and so we generally don't recommend it at this point. So what about radiation? If we look at radiation-based procedures during pregnancy, how much radiation does a fetus get, first of all, from some of the more common procedures that we do? Diagnostic x-ray, very little. PE protocol CT, 0.01 to 0.66 milligray, so not a lot. Prospective gating of a coronary CTA gives you 1 milligray. Retrospective gating, usually about 3 milligray. Coronary angiography, 0.074 milligray, not very much. Coronary and peripheral interventions, generally about 0.0023 to 0.012 milligray per minute, and that depends on angles, collimation, magnification, et cetera. Myocardial perfusion imaging, 5.3 milligray. Please don't do nuclear stress tests on pregnant women ever under any circumstances. I would prefer any other test to a NUC. VQ scans, 0.1 to 0.8 milligray. So notice that that's 10 times greater than a CT angio, and so we actually recommend the PE protocol CT if you have a high suspicion. If you have a high suspicion of coronary disease, if somebody comes in with typical angina and you're torn about what to do, the cath lab is actually your answer. So radiation in the fetus, how much radiation can a fetus get? So the recommended, the Nuclear Regulatory Commission recommends fewer than 5 milligray. If you're under 50 milligray, the fetal risk is negligible with a conceptus loss of 0.17%, and even that, those data are a little bit difficult to tease out because miscarriage rates at baseline are relatively high early in pregnancy. If they're under 100 milligray, there is no justification for termination. I have seen patients who have been told that they needed to terminate their pregnancy after they've had a couple of CT scans or maybe even a nuclear stress test, a VQ scan. That is incorrect. 100 to 150, you consider the individual circumstances, and remember that this exposure early in pregnancy is much more impactful than it is later in pregnancy. If you're talking about a fully formed fetus mid-second trimester on, then the impact of radiation is much less. If they're greater than 150 milligray, there's possible fetal damage, and you should consider termination greater than 200 early in the pregnancy, then termination is generally recommended. So what about radiation-based procedures? You've got a pregnant patient. She needs a cath. She needs a CTA. She needs a mechanical thromboembolectomy. What do you do? First, you want to get a good informed consent, and I always give moms those numbers that I just gave you because moms are terrified of radiation, and I've had to sort of prod them along to get them to consent to some of these procedures because they say, oh no, my baby, the radiation exposure, et cetera, and so I give them those hard numbers. I say, listen, this is the exposure that you expect. This is generally within the safely considered limit. We will be okay because as all of us in Cardio Obstetrics have come to learn, mom will put her baby before herself every single time. Remember to focus on mom. You've got to have a living vessel to have a living baby. If the patient is viable, keep a C-section tray and a baby warmer close at hand. If the patient is between 20 weeks and whatever your institution considers viable, keep a C-section tray in hand because if that patient codes, resuscitative hysterotomy has got to be on your list of things to do to make things better. External shielding. We are wrapping these poor moms up in heavy shielding. It is of limited value. It probably reduces the fetal radiation dose by about 3% although it has psychological advantages both to the mom and to the providers. And so we continue to do it, but it really probably doesn't help very much. It may increase maternal discomfort or on the flip side, it may decrease maternal discomfort if she feels better about being shielded. Internal shielding, however, is very beneficial. So tight collimations, using low dose fluoro, using fluorosave rather than Sine, although if you look at interventional procedures, about 70% of the radiation for most interventional procedures does not come from Sine angiography. It comes from fluoro. You want to avoid high magnification and you want to avoid steep angles. So we favor AP projections if possible. Avoid direct radiation to the abdomen and position the patient just slightly on the left side, as Dr. Bortnik said, to minimize IBC compression. So I usually put a small wedge or a rolled blanket under the right side of the patient to tilt them very gently to the left. With regard to PCI, depending on the skill set, consider femoral versus radio access. So if you've got a good radio operator, the radiation is going to be less because you are not traversing the abdomen and going past the fetus. However, if you have somebody who's not a great radio operator and it's going to take them 10 minutes of catheter flipping to stumble upon a coronary, then they may be better off with a femoral procedure or not working on your pregnant patient at all. Also, you want to rely on IBIS to reduce radiation. If you're going to use OCT, you can combine OCT with your preliminary pictures and your final pictures and try to avoid using radiation throughout the procedure. Per the American College of OBGYN, pregnant women should never be denied an indicated procedure because of pregnancy. Pregnancy alone is not a contraindication to radiation-based procedures. And I wish that I could make a sign that says that and hang it up in the emergency room and in every cardiology clinic across America. So what if the doctor's the pregnant one? Then what do we do? So a Sky survey in 2011 was completed. It had 380 respondents and they found that 65% of respondents were allowed to work in the cath lab during their pregnancies, while 35% were prohibited from working in the cath lab while pregnant. Aside from the obviously paternalistic viewpoint that you see here of telling a grown woman with her own fetus what she can and can't do, the current data do not suggest a significantly increased risk to the fetus when pregnant women work in the cardiac catheterization laboratory with appropriate shielding. And thus, there is no justification for preventing pregnant women from performing procedures in the cath lab. And so when the doctor is the pregnant one, if she would like to, she is more than welcome to continue working in the cath lab with minimal risk to her fetus. I cathed from the moment I knew I was pregnant until I got put on bed rest at 35 weeks. And my kid has a lot of issues, but I think they're mostly genetic and related to being 12 and not related to the cath lab at all. But I know there is a lot of fear among female fellows and female physicians. And so I would like to dispel that myth. And so that's all I have for today. And I know we're going to do questions, I think, at the end. So thank you very much for joining us.

pregnant women

cath lab management

fetal risk mitigation

coronary angiography

PCI in pregnant women