Lower Triglycerides Lower Risk Of Cardiovascular Disease Early Ablation For Atrial Fibrillation

This week’s topics include early ablation for atrial fibrillation, early management of heart attacks, lowering triglycerides and cardiovascular outcomes, and more effective defibrillation. Program Notes: 0:51 Heart attack treatment times 1:51 Only 17% of the time as directed 2:51 Every hospital has to evaluate 3:50 Thrombolytic therapy 4:01 Pemafibrate and cardiovascular effects 5:01 67% with previous CVD 6:04 Higher incidence of adverse renal events 6:23 Refractory defibrillation 7:23 Double defibrillation had longer survival 8:23 Just experience 8:30 Early treatment of atrial fibrillation 9:30 Much less repetitive fibrillation 10:30 Remodels vaginal tissue 11:30 Both are done safely in experienced centers 12:49 Finally Copy: Elizabeth: Does lowering triglycerides help reduce the risk of cardiovascular disease? Rick: Rapid treatment of acute heart attacks. Elizabeth: Does treating atrial fibrillation early help prevent the condition from developing further? Rick: And making defibrillation more effective for people in cardiac arrest. Elizabeth: That’s what we’re talking about this week on TTHealthWatch, your weekly look at medical headlines from the Texas Tech University Health Sciences Center in El Paso. I’m Elizabeth Tracey, a medical journalist based in Baltimore. Rick: And I’m Rick Lange, president of the Texas Tech University Health Sciences Center in El Paso, where I’m also dean of the Paul L. Foster School of Medicine. Elizabeth: Rick, of course, this is AHA (American Heart Association) meeting week, so everything this week is from the heart. As long as you’re good-hearted, I’ll let you start it. Rick: Well, Elizabeth, let’s talk about one of the most common heart conditions, heart attacks, when there’s a blood clot in one of the arteries that blocks blood flow to the heart and that can lead to immediate irregular heart rhythms, in in which case individuals should be defibrillated. Or if they survive without a rhythm disturbance, there is part of the heart muscle that dies. We have a saying called “Time is muscle”. What you want to do is open that artery as quickly as possible to preserve the heart muscle. This was a study that looked at two different time periods — 2018 and 2021 — of nearly 115,000 patients treated for a heart attack at more than 648 hospitals called the Get With The Guidelines – Coronary Artery Disease (GWTG-CAD) Registry. They wanted to ask, “How well are we doing, and does treating heart attack earlier actually affect mortality?” There are several different goals. We want to make sure that the first medical contact when they open their artery is less than 90 minutes. In people who come to a hospital that does not have a cardiac anatomy lab, this happens only about 17% of the time. In those people who have the artery opened early, it reduces mortality by about 50%. Anything and anywhere delayed less than the guidelines recommend essentially doubles mortality. That’s what this study showed. Elizabeth: This study is published in JAMA. I would like to hear your thoughts on what accounts for these delays and it would be helpful to engage with, for example, EMS to ensure that they are always transported to hospitals that have a catheter lab. Rick: It’s different for different locations. One of the things the authors suggest is for each hospital to identify where your delay is and address it. You want to train EMS people to recognize a heart attack in the field. They can call the hospital in advance and they can already start activating the heart disease labs. The second, as you said, is to make sure that people get to a cardiac lab or regional center as quickly as possible. For those who are just coming into the hospital, it’s also important to see them very quickly to do an EKG so we can see if it was a heart attack and then activate the cardiac lab. There are several factors and they are local. That’s why they need to be evaluated at the hospital level. Elizabeth: You’re saying that each hospital needs to take a look at where their delays are occurring in that particular facility. I wonder how complicated it is to follow someone as they come to your ED and then go through all the assessment and treatment. Rick: It’s really not too hard. Most hospitals should set up committees to do this. For example, you know you want the person from the time they show up in the emergency department to have an EKG in less than 10 minutes. Each of these can be segmented and evaluated. Elizabeth: One question I have, of course, is that we’ve seen a lot about “maternity care deserts” in different parts of the country. Let’s talk about the distribution of heart disease labs. Rick: You would like — when a person comes to a hospital that doesn’t have a cardiac lab — is to get them out within 30 minutes. It is obviously more difficult in very rural areas. In these settings, the patient often receives thrombolytic therapy that should dissolve the clot. It’s not as effective as a balloon, but it’s still much more effective than not treating the patient and then moving them around. Elizabeth: Let’s turn to the New England Journal of Medicine, where we’ll be spending the rest of our time this week, looking at heart attack prevention. We know that many things are involved in someone’s risk of a heart attack. One thing is high triglyceride levels. It is not clear, however, whether lowering these levels will reduce the incidence of cardiovascular events. This agent called pemafibrate was tested in this study to lower triglyceride levels and was also associated with improvements in other lipids. The question is, does this really help? This was a study that enrolled patients with type 2 diabetes, mild to moderate hypertriglyceridemia, and it was a triglyceride level of 200 to 499 — which doesn’t sound moderate to me, but maybe you’ll disabuse me of that — mg per dl , and low levels of high-density cholesterol. They were given pemafibrate twice a day or a matching placebo. They had nearly 10,500 patients, 67% of whom had prior cardiovascular disease. They were followed for 3.4 years. They saw that pemafibrate was able to achieve a 26%+ reduction in triglycerides, 26% in VLDL, and nearly 26% in residual cholesterol. The bad news is that it really wasn’t very helpful relative to those other results they were looking for, despite seeing improvements in that profile. Rick: This is one of the different agents that have been very effective in lowering triglycerides in people who have high triglycerides, yet it has not reduced the risk of heart attack, stroke, or cardiovascular death. This is very different from the story with cholesterol, and lowering cholesterol, especially LDL, has been beneficial. In this particular study, they targeted a specific population they thought might be helpful: diabetics, high triglycerides, and low HDL. This was a team that, gosh, they thought if anything was going to work this was going to be the team. Again, lowering triglycerides did not actually improve cardiovascular outcomes. Elizabeth: Yes. It seems like it must be a substitute for something else going on. They also had a higher incidence of adverse renal events and VTE. Rick: Relatively small. Then when they went and looked at it, it wasn’t really that big. One of the things that was interesting, though, is that this may have some beneficial effects on the liver. They may shift their focus from using this for cardiovascular disease to liver disease or fatty liver. Elizabeth: Let’s go to your next one, like I said, also in NEJM. Rick: I mentioned the fact that when people have a heart attack, one of the complications is an irregular heart rhythm, or what’s called ventricular tachycardia or ventricular fibrillation. This is often what causes death in people who have an out-of-hospital cardiac arrest. There are some people who are simply resistant to defibrillation with the standard method. What these researchers did was, gosh, can we change the defibrillation method a little bit and make it more effective in people who have a resistant heart rhythm? The two ways you can do this are usually with the paddles placed on the front of the chest. What if you put one in the front and one in the back? The second is to use two defibrillators, one where the flaps are placed in the front and another where they are placed in the front and back, and then defibrillate the patient sequentially. In this particular study, they tried 3 different techniques, moving the paddles, doing a double shock, and then just trying to replicate the standard fibrillation. What they found was when they used double defibrillation, it had a longer survival than standard, 30% versus 13%. When the front and rear paddles were simply switched, it was also associated with higher survival, 22% versus 13%. This is great news regarding the greater success of refractory defibrillation. Elizabeth: I’m going to ask you to recall, many years ago, an idea that CPR should be given dorsally versus abdominally. Talk to me about why this might work. Rick: When you think about where the heart is, where the left ventricle is, a lot of it is on the back side, the back of the heart. When you only place the paddles on the chest wall, you don’t get as much…