PodMed Double T is a weekly podcast from Texas Tech. In it, Elizabeth Tracey, director of electronic media for Johns Hopkins Medicine, and Rick Lange, MD, president of the Texas Tech University Health Sciences Center in El Paso, look at the top medical stories of the week. A transcript of the podcast is below the summary.
This week's topics include a patch to diagnose atrial fibrillation, USPSTF recommendations on nontraditional risk factors for heart disease, the role of genetics in congestive heart failure, and multivitamins and heart disease.
Program notes:
0:57 Patch for diagnosing atrial fibrillation
2:00 More likely to receive care
3:01 These were all people at risk
3:14 USPSTF and nontraditional risk factors for cardiovascular disease
4:14 No evidence that therapy is altered
5:15 In individuals with no risk factors
5:50 Multivitamins and heart disease
6:50 Adjusted for physical activity no benefit
7:31 The genetics of heart failure
8:31 Does increase one's risk if biological parent has it
9:31 A complex trait
10:18 End
Transcript:
Elizabeth Tracey: Is heart failure inherited?
Rick Lange, MD: Can you wear a patch at home to diagnose a common heart condition?
Elizabeth: What is the utility of so-called non-traditional risk factors in assessing cardiovascular disease risk?
Rick: Should we be taking multivitamins to prevent heart disease?
Elizabeth: That's what we're talking about this week on PodMed TT, your weekly look at the medical headlines from Texas Tech University Health Sciences Center in El Paso. I'm Elizabeth Tracey, a medical journalist at Johns Hopkins, and this is going to be posted on July 13th, 2018.
Rick: And I'm Rick Lange, President of the Texas Tech University Health Sciences Center in El Paso and Dean of the Paul L. Foster School of Medicine.
Elizabeth: Rick, this week we're in your roundhouse. Every single thing we're talking about is relative to cardiology, most of it from the Journal of the American Medical Association.
Rick: And I'm in heart heaven, so let's go!
Elizabeth: Ooh! I think you think of these things at night. I don't know. Let's start with the patch for diagnosing atrial fibrillation. That's in JAMA.
Rick: This very pragmatic study showed that if you use a home-based, continuous ECG patch, something you wear on your chest, they're three times more likely to diagnose atrial fibrillation than just doing standard care. About a third of individuals, by the time they age, will have experienced one or more episodes of atrial fibrillation, and we know that individuals that have atrial fibrillation are at an increased risk of stroke. Typically they're treated with anticoagulation or blood thinners. If you wear a patch at home, it continuously monitors your EKG for a 2-week period. Is that more likely, in asymptomatic individuals, to detect atrial fibrillation? What the study showed was that it's three times more likely to detect it as compared to standard approaches.
By the way, when they followed those individuals, they gave them that information. They didn't give it to the doctor. Those individuals were more likely to seek care from their doctors, more likely to be on anticoagulation, and more likely to receive other treatments for atrial fibrillation. We don't know if that improved their outcome, and we don't know what the cost effectiveness of this particular strategy is, either.
Elizabeth: Let's hear, in your opinion, what the barriers are to the implementation of the use of this patch for folks at home.
Rick: The biggest barrier is, this is in asymptomatic individuals and does it improve outcome? We need more studies. But the nice thing about this particular trial, it's real world. It wasn't a randomized, controlled trial. It didn't require a huge database or it wasn't at a particular site. And so from that standpoint, this gives us some insight into how we might do future large trials looking at this and other therapies.
Elizabeth: Great idea. I guess one of the questions I have is in whom is it important to monitor for atrial fibrillation in this way, because should we wait until somebody is 65 or older, for example? Is atrial fibrillation of uncertain clinical importance in folks younger than that?
Rick: It certainly has a higher incidence the older you are, but these were all people that were at risk for atrial fibrillation. For example, they had congestive heart failure or hypertension.
Elizabeth: You've segued us very nicely, then, into the first one that I'm going to discuss at a little greater length. That's also in the Journal of the American Medical Association. The USPSTF [U.S. Preventive Services Task Force] [was] taking a look at so-called non-traditional risk factors in assessing someone's risk for cardiovascular disease. What they focused on was the ankle-brachial index, high-sensitivity C-reactive protein, and coronary artery calcium scores, all of which have been -- at least as far as I can tell -- utilized a lot more often in clinical assessments of people reported to be at risk or even in the so-called worried well, and I would include myself in that number because I've had a coronary calcium scan.
The upshot of the whole thing is the USPSTF said the evidence is insufficient to assess the balance of benefits of harm of adding all three of those to the traditional risk score for people who are worried about their cardiovascular disease risk. I'm not sure exactly what that means. I guess it means that people are going to be paying out-of-pocket for them if they want them.
Rick: Do any of the three add any value to the traditional risk factors? We're talking about things like diabetes and high blood pressure. There is no evidence that the use of this information alters the therapy significantly or improves outcome. Now the one exception may be coronary artery calcification [testing]. In very low-risk individuals, there's no benefit to coronary artery calcification. In very high-risk individuals, there isn't either. In the intermediate-risk individuals -- and you're trying to decide how intensive should the therapy be for that individual -- the coronary artery calcification can move them into a low-risk or a high-risk group. But even then, we don't have any studies showing that that actually improves their cardiovascular outcome.
Elizabeth: Right, and so I guess one question I have is what is with this search for these so-called non-traditional risk factors? I'm not sure how they add to the scores that we already have.
Rick: Elizabeth, your point is well taken. There is an occasional person that has heart disease with no risk factors, but that's really not very common. Most individuals have one or more of the risk factors. If there are things that can identify coronary artery disease or the risk of heart disease in an individual with no risk factors, we'll find that helpful, but none of these particular things fall in that category.
Elizabeth: As I suggested, in view of this recommendation, I guess if folks want these tests, they're going to be paying out-of-pocket, at least in the short term.
Rick: I'm particularly concerned because there's a lot of direct patient marketing that says, "You need to have these tests done," and that they'll detect undetectable heart disease. What I want our listeners to know is they're no better than the traditional risk factors, and the traditional risk factors really don't require these expensive tests. They only involve a blood test and then other routine screening.
Elizabeth: Let's turn from here to Circulation, a little brief foray out of the Journal of the American Medical Association. That's taking a look -- it's one of the circulation journals -- at is there any benefit to a multivitamin with regard to one's risk of heart disease?
Rick: You may or may not be surprised to know that up to 70% of people over the age of 64 take one or more multivitamins. This is a $21 billion business in the United States. It's not just limited to patients, but oftentimes, it's recommended by well-intentioned physicians.
Do multivitamins reduce cardiovascular disease mortality, or morbidity? In short form, no. What these investigators from Hopkins did was they looked over 46 years at clinical trials and prospective cohort studies that looked at individuals taking multivitamins and assessed their risk of heart disease. What they determined in looking at 18 different studies of over 2 million individuals, multivitamins or mineral supplements did not reduce any of those cardiovascular events.
It didn't matter what the patient's age was, what their gender was, what their diet was, their smoking status, even adjustment for physical activity. Multivitamins did not offer any benefit.
Elizabeth: As we've talked about so many times, gosh, every time we examine this and for whatever positive outcome we're looking for, it just seems like we never really see a benefit to taking those, at least in this country where we have so much supplementation of our food.
Rick: Absolutely. They actually looked at studies inside the U.S. and outside the U.S., and because vitamin fortification and our diets have changed substantially over the last 50 to 100 years, very few individuals actually have vitamin deficiencies.
Elizabeth: I'm going to invoke, again, that phraseology I employed before, the worried well.
Rick: Elizabeth, let's talk about the genetics of heart failure.
Elizabeth: That's in JAMA Cardiology. We have to take our hats off to folks in Europe, of course, having much more robust health data relative to their populations than we do here in the United States.
This was a Swedish study, and it took a look at 21,000+ adoptees. They also had over 35,000 adoptive parents and 43,000 biological parents as part of this cohort. They were taking a look at hey, what happens with heart failure? Is it really inherited?
Now admittedly, those giant numbers shrink quite a bit when we take a look at the actual incidence of heart failure in the adoptees. There were only 194 cases, so at least for me, that reduces the power of this study a little bit. Almost 4,000 cases of heart failure in the adoptive parents and about 3,600+ of heart failure in biological parents. OK, well, what's the factor that's relative to the biological parent and found out that it is, actually, a factor. It does increase one's risk of developing heart failure if your biological parent had heart failure. In view of the fact that heart failure is an increasing diagnosis, taking a look at the heritability is probably a good idea.
Rick: When you try to say, "Is there a familial inheritance?" and the fact that the kids usually live in the same environment, it's hard to tease out the genetics from the environment. But obviously, if the kids are adopted by different parents, they have different environments and you're able to more likely assess the heritability of a particular condition, in this case, heart failure. As you noted, if your biologic parent had heart failure, it increased the children's risk about 50%. Their adopted parents, even if the adopted parents had heart failure, didn't increase the risk of the adopted kids, so it's not environmental. In fact, it's genetic.
They even went a step further, Elizabeth. There are cardiomyopathies we know where there's a single gene that's affected that affects a part of the heart. When they took those out, even after that, there was a significant increased risk of heritability.
This suggests it's a complex trait. It's not just a single gene. As you suggest, there are multiple things that can cause heart failure: hypertension, alcohol, for example, ischemia, valvular heart disease. But even then, there's probably a genetic predisposition that's added on top of those things.
Elizabeth: And worth taking as a part of the history when trying to assess.
Rick: Absolutely. This is going to inform us to look more closely to say, "Can we identify what the genetic changes are, what the polygene effects are?"
Elizabeth: On that note, this week on the blog I'm going to highlight the patch for detecting atrial fibrillation. That's a look at this week's medical headlines from Texas Tech. I'm Elizabeth Tracey.
Rick: I'm Rick Lange. Y'all listen up and make healthy choices.