Melanie Cole (Host):  Welcome to the podcast series from the specialists at Penn Medicine. I’m Melanie Cole and we’re speaking today with Penn Medicine Cardiologist Dr. Monika Sanghavi about myocardial infarction in nonobstructed coronary arteries or MINOCA, a syndrome that appears in up to 14% of patients having acute myocardial infarction. Dr. Sanghavi, we know from the MINERVA study and others that little is known about the clinical profile or the functional and psychosocial status of patients with MINOCA. Do we know who the typical patient is? Do we know who is at risk? 

Monika Sanghavi, MD (Guest):  Thank you so much for having me. It’s a pleasure to be here. So, if we think about MINOCA, we have to compare it to your typical coronary artery disease patient. Because the only way that MINOCA is diagnosed is when you are in the CATH lab. So, the typical MI patient and a MINOCA patient present the same way, they have chest pain, EKG changes, biomarkers suggestive of an MI but the difference is when they are taken to the CATH lab, MINOCA patients do not have obstructed coronary arteries and that’s the diagnosis of MINOCA. When we look at the epidemiology of MINOCA, we can see that these patients, they are usually younger. They are usually female. And often, ethnic minorities.

Host: Could you elaborate on any cause that we know of? 

Dr. Sanghavi:  So, when you have a diagnosis of MINOCA, it’s absolutely important for a physician to look into this a little bit further. And the reason being, is that for many years MINOCA patients were sent home thinking that they don’t have obstructed coronary arteries, they’re fine. However, what we’ve seen is these patients actually are at higher risk for persistent chest pain, they are at higher risk for recurrent hospitalizations for chest pain. They are more likely to have a recurrent MI. And actually even more likely to die than someone who did not have the myocardial infarction in the first place. And so if we think about this, it’s really important to get to the underlying cause for these patients so that we can understand how to treat them.  Studies have shown that there’s a wide variety of causes of MINOCA:, spanning from coronary vasospasm, which is basically when the coronary arteries spasms enough that it causes obstruction of flow to the myocardium. There is SCAD, spontaneous coronary artery dissection, which is much more common in young women; microvascular disease, which is a problem with or a dysfunction of the small blood vessels of the heart. There are many smaller blood vessels that provide and regulate blood flow to the heart that we don’t see on angiogram. And when these are dysfunctional, they are also thought to be able to cause a myocardial infarction. Other things include plaque erosion as opposed to plaque rupture and plaque erosion is thought to be more common in women. And so, there are so many possible causes. There are also some people who have shown that sometimes it isn’t even a myocardial infarction at all and it’s actually myocarditis or Takotsubo, which is a stress induced cardiomyopathy. And that’s why it’s so important for your physician to really look into the underlying cause and try to understand what caused the damage to the myocardial infarction.

Host:  Well I’m glad you mentioned spontaneous coronary artery dissection or SCAD. It’s a condition that seems to affect a similar population as MINOCA. Is there a link between the two and as a cardiologist, is this event a different entity compared to one due to atherosclerosis?

Dr. Sanghavi:  Oh most definitely. So, SCAD is spontaneous coronary artery dissection and it’s one of the most common causes of heart attacks in women under the age of 50. So, it actually makes up about 35% of all heart attacks in women under the age of 50. And so if someone has a MINOCA event and especially if they are a young woman; it becomes really important to look for SCAD. It takes a high level of suspicion to really be able to see it sometimes and it takes some training of the eye to be able to see it. If you suspect SCAD,you see tortuous coronary arteries if there is a recent pregnancy, because those women are even more likely to have SCAD. SCAD was thought to be a very rare disease.. It now makes up about one to four percent of all acute coronary syndrome cases and as I mentioned, about 35% of all MIs in women under the age of 50, and about 45% of pregnancy related MIs. SCAD is very different than your typical atherosclerotic coronary artery disease. The people who are affected by SCAD look completely different than your typical MI patients. One, they usually don’t have a lot of the risk factors that you have with coronary artery disease. They are not usually diabetic. They don’t necessarily have high cholesterol. They are not necessarily smokers. They are actually very healthy, active young women who are having these events. And the problem with this is that because they look so different than what we typically think of when we think of a patient having a myocardial infarction; that they are often overlooked. So oftentimes, these women are sent home from the ER with chest pain because they don’t look like a typical person with chest pain. So it’s important for these women to be advocates for themselves. In terms of the underlying etiology of SCAD; I think we are kind of still beginning to understand it. The pathology is that there is basically a blood pocket or a hematoma in the lining of the blood vessel.that causes obstruction to the lumen, preventing blood flow. Some people think that the inciting factor is a rip in the blood vessel lining itself. Others think that it’s actually the blood pocket that causes the tear or the dissection flap. But they’ve even seen patients who had this blood pocket in the blood vessel but don’t have the tear. So, that’s why it’s unclear whether the actual underlying pathology is that hematoma or that blood pocket or if it’s the underlying dissection. One other thing that I want to point out is that FMD or fibromuscular dysplasia and underlying vasculopathy is very common in these patients and so, the recommendation is that all women with a history of SCAD be screened for underlying arteriopathies. And that includes basically a head to pelvis scan to make sure that there’s no aneurysms or evidence of fibromuscular dysplasia.

Host:  Dr. Sanghavi,  I’d like to talk about imaging now. Do you think it’s important that providers have this in their minds, at the CATH lab or even before they enter it, and tell us a little bit about what you’re doing as far as coronary angiography as first line imaging and some of the risks that come with that when you are looking for MINOCA or SCAD.

Dr. Sanghavi:  Right, so, it’s imperative, that any patient with suspected SCAD or MINOCA get an angiogram. Because if you are having a MINOCA event or you are having an MI, you can’t distinguish atherosclerotic coronary artery disease from a MINOCA event unless you do an angiogram. The same is true for a patient with SCAD. It’s essential to do an angiogram because other imaging modalities such as CT coronary angiogram; they are not as good in terms of diagnosing SCAD. And so, it’s really essential that these women undergo angiogram to establish the diagnosis. It’s really important to have a high index of suspicion because these aren’t your typical coronary artery disease lesions they can be missed, overlooked if you don’t know what to look for. The other thing to think about, is that sometimes these women are at increased risk for catheter induced injury to blood vessels. And so, I think physicians, interventional cardiologists try to take a lot of care to try to prevent any kind of iatrogenic damage from the catheters.

Host:  Let’s talk about treatment for a minute. So, is treatment of MINOCA dependent upon the underlying cause, which you may or may not know? Please tell the listeners what you take into mind regarding duration of hospital stay and what you determine as far as treatment options available.

 Dr. Sanghavi:  So, when we think of a MINOCA event, for a long time, we just treated this as an MI.  But we know now that this is not always the case. If you are able to determine the cause of the MINOCA event, then you would treat the underlying cause. But if you don’t know what the underlying cause is, the treatment is actually controversial. There are very limited studies to look at the treatment options. This is in contrast to SCAD. If you determine that the SCAD  is the cause of the MINOCA event, the treatment is also controversial because we don’t have any randomized control trials to look at. But in general, we usually treat with beta blockers and then aspirin and Plavix, so dual anti-platelet therapy. Although the duration of DAT, or dual anti-platelet therapy is controversial. We’re not sure how long people should be on it and so there is a wide variation in practices across the country in how long people treat with DAT therapy. Statins are another area of controversy. Some people start it but the current guidelines or recommendations say you should only start statin therapy if there’s another indication. So, let’s say the patient does have high cholesterol or they do have significant plaque build up in the blood vessels of their heart; then you would treat with statins. But don’t use the SCAD event as an indication for the statin treatment. 

Host:  As we’re talking about treatment, what are some other supportive therapies? What do you want other providers to know about this picture?

Dr. Sanghavi:  So, I want to first address length of stay. So, for a MINOCA event, we usually just keep patients in the hospital maybe for a day or two days depending on the underlying cause. If the underlying cause is thought to be SCAD, the recommendation is usually to keep the patients in longer because there’s concern that that hematoma or that blood pocket can expand and cause further obstruction that would require intervention. Because in SCAD usually we don’t stent unless we absolutely have to. In terms of additional treatment options, a very, very important one is cardiac rehabilitation. So, I’m a strong believer in cardiac rehab and I do recommend that to all of my MI patients including my SCAD patients. But SCAD patients have to be careful because we believe that extremes of exercise or emotion can be triggers for SCAD. There are a good percentage of women who present after significant exertion with their first SCAD event. And so, there’s not only an underlying fear, but there is true risk that if they significantly exerted themselves again, that could they have a recurrent event. The recommendation, this is more of an expert opinion, is that women with a history of SCAD should try to avoid anything extreme. Extreme exercise, extreme weather when they are exercising,  really hot weather or really cold weather and there’s a board’s scale of exertion, perceived exertion. So, trying to stay in really the middle portion of that scale extreme exertion can be a trigger for SCAD; extreme stress can also be a trigger for SCAD. So, when we’re looking at women and we’re counseling them in clinic after their SCAD event; I always take into account what their triggering event was. Was it after pregnancy? Was it after a significant stressful event? Was it during extreme exercise? And then I counsel accordingly in order to help try to prevent a future event. Although I still recommend cardiac rehab for all these patients but with these parameters in mind.

Host:  As we wrap up, Dr. Sanghavi, tell other providers what you would like them to know about what you’re doing at Penn Medicine and when they should refer patients.

Dr. Sanghavi:  At Penn, we are part of the iSCAD registry to help accumulate data from patients with a history of SCAD,  it’s still considered a relatively rare disease and so the more patients we have collectively, the more information we have collectively, the more information we can glean and the better results we can glean from cumulative data.  I would say that any physician who has any suspicion for a prior SCAD event or MINOCA event where they just want a little bit of help trying to tease out what the cause is; definitely call us or you can refer to us. This is something we see often in our clinic and with MINOCA patients, time is important because some of the imaging studies such as cardiac MRI that we would want to get after a MINOCA event are kind of time sensitive in the sense that it requires us to get the MRI quicker in order to be able to make the underlying diagnosis. The farther out we are from the event, the more likely that we might never know what the underlying cause for the MINOCA event is. But we are happy to see any patient that has a history of it and if physicians have any questions about the diagnosis.

Host:  Thank you so much Dr. Sanghavi. What a very fascinating topic. Thank you again for joining us. And that concludes this episode from the experts at Penn Medicine. To refer your patient to a specialist at Penn Medicine you can please visit our website at www.pennmedicine.org/refer or you can call 877-937-PENN for more information and to get connected with one of our providers. Please remember to subscribe, rate and review this podcast and all the other Penn Medicine podcasts. I’m Melanie Cole.