Cardiac Arrest: Can We Improve Outcomes for These Patients?
David Seder, MD
People who arrive at a hospital in cardiac arrest (their heart has stopped) have poor chances of full recovery. The PEARL Study looked at ways to improve those outcomes. Currently some of these patients undergo heart catheterization, while others do not, depending on the physician’s judgment. But what if everyone had a heart catheterization? Would it improve outcomes?
A note about the study: Most medical research studies require an individual’s informed consent in writing before they can be enrolled, but patients arriving in cardiac arrest cannot speak for themselves. They may not have a family member there who can speak for them. Therefore, this study required public outreach to make the community aware of it and provide a way for people to opt out. The PEARL study is closed, a new study (ACCESS) is now open.
Download podcast (.mp3)
Dr. David Seder is here to explain the study and what it means for your health.
Dr. David Seder (Guest): Hi, Melanie. Thanks for the chance to talk to you about this today. Cardiac arrest is when the heart stops. As soon as the heart stops, no blood flow is pumped out to the rest of the body. Only a few moments after that people, lose consciousness. Then, the clock starts ticking in terms of your ability to resuscitate a person and bring them back to life. Some people think that you only have a few minutes but, in fact, we’ve been successful at resuscitating people who’ve been dead for much longer than that. After the patient is resuscitated with CPR or shocks or medications, begins the process of trying to stabilize them and nurse them through neurological recovery and fix anything that may be wrong with their heart. That’s what this study is about.
Melanie: So, tell us what it involves. If someone comes in full arrest and CPR, whatever, you’ve brought them back--which is amazing in itself--then what happens what does this study involve?
Dr. Seder: Well, about half the time when people have a cardiac arrest event in the community, the cause is a heart attack. Specifically, it’s a blockage in one of the heart arteries or the coronary arteries. That blockage prevents blood flow to the heart. The heart then goes into an abnormal heart rhythm that doesn’t circulate blood and everything stops. So, after the patient is resuscitated, meaning we get their heart jump started again, a lot of times we have to treat the heart attack. That’s what this study is about. So, right now, when people come in after being resuscitated from a cardiac arrest event, they’re typically in a coma and because they’re in a coma, oftentimes doctors don’t think to try to stop the heart attack before they wake up. They want to see if they’re going to wake up first from their coma and if there’s irreversible brain damage before they think about fixing the heart. In this study, we are testing the hypothesis that fixing the heart and stopping the heart attack very early on, immediately when they come in to the hospital, may help more people survive and may actually help their brains recover.
Melanie: And how would you do that?
Dr. Seder: The way the study works is, at present, when a person is resuscitated from a cardiac rest, we take them to the intensive care unit, we cool their body temperature down and then we wait for about 24-48 hours to wake up. We warm them back up again and, at that point, we consider whether or not to do a cardiac catheterization and shoot pictures of the arteries of the heart and fix anything that may be plugged up. In this study, half of the patients will be randomized or randomly selected to undergo cardiac catheterization immediately in which the heart arteries are imaged and any blockages are opened right then and there as soon as they present to the hospital. That would be a change from how we typically do things now. There are some preliminary data that may suggest that we save lives and lead to better brain recovery.
Melanie: What about the other half of the group? This is an amazing bit of resuscitation science and really can make a difference in what happens after cardiac arrest but what about the other half that do not go into that part of the study?
Dr. Seder: Well, this is how research is conducted. The problem is, if we gave everyone the new treatment, then we would have no way to compare that group of patients to other patients and we wouldn’t know if the early treatment worked. Whenever you have a study like this where you don’t know whether the intervention that you’re suggesting is helpful or not, you have to choose the intervention for half the patients and the current standard treatment for the other half. So, in this study, half of the patients will undergo urgent coronary angiography and revascularization. The other half will undergo delayed coronary angiography and revascularization. So, there’s no way to know when a patient is enrolled in the study which group they will be in.
Melanie: Who can take part in this study?
Dr. Seder: Well, that’s another interesting feature of the study. In this study, the need to do the experimental intervention immediately is urgent and so, the ability to ask family members for their permission to participate in this study is quite limited because usually the person arrives in the hospital by an ambulance with no family members around; they don’t know about it yet. They only find out a few hours later after the dust has settled. We need to be able to randomize patients to one of these two treatments immediately. To do that, there’s an interesting process called the “exception from informed consent” which will be employed in this trial. It’s the first time in Maine, to my knowledge, that this has been done. What it means is that, rather than asking the individual patient’s families for permission to participate in the study, we ask the community and we’re required to go around for a long time, usually about six months, talking about the study with different groups and trying to get permission from the state from the people of Maine, as it were, to do the study. Then, if they give permission and the institutional review board at our hospital agrees to it, then we will randomize patients to these treatment groups and only after they have participated in the study will they personally, or their families, be asked for permission to participate. Now, that’s not true if the family members are present in the emergency department. If we can find, either on the telephone or in person, a family member to consent then, of course, we will ask their permission to participate. If we can’t, then the consent process defers to the community consent and we can randomize patients and ask their permission afterward.
Melanie: What if someone specifically says they do not want to be a part of the study?
Dr. Seder: That’s a great question. In fact, under those circumstances, we will be very, very careful not to involve anyone in the study who does not want to participate.
Melanie: Okay. So, Dr. Seder, now give a little bit of information about how people can find out more about this study and you’d like them to take a short survey as well.
Dr. Seder: Yes, it’s very important that people take a short survey about this study and give us their opinion about whether or not participation in the study is appropriate from their point of view. For more information, people should go to the Maine Medical Center website where they can get more information about the study and fill out a short survey in which they can describe whether or not they feel participation in the study is appropriate.
Dr. Seder: In the past, patients who have been resuscitated from a cardiac arrest event have not done well. About 40% of them survived to be hospitalized and only 25 or 50% of those 40%, so 10-20% overall, will survive and have a good outcome after resuscitation. We’re desperately trying to get those numbers higher. However, there have been significant improvements over the last five or ten years in the quality of care that people have gotten. So, the outcomes have improved dramatically. We are very hopeful that this study will show that early cardiac catheterization, fixing the heart immediately after being resuscitated from an arrest, will help people because that might be a way to improve survival.
Melanie: Thank you so much, Dr. Seder. It’s absolutely fascinating. We applaud all the good work that you’re doing. You’re listening to MMC Radio and for more information you can go to mainemedicalcenter.org. mmc.org. This is Melanie Cole. Thank you so much for listening.