Coffee and Heart Function; from TTHealthWatch is a weekly podcast from Texas Tech

Podcast at link, transcript below. Nothing here is going to change my coffee consumption.

Coffee and Heart Function; from TTHealthWatch is a weekly podcast from Texas Tech 

TTHealthWatch is a weekly podcast from Texas Tech. In it, Elizabeth Tracey, director of electronic media for Johns Hopkins Medicine in Baltimore, 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.

This week's topics include cardiovascular impact of low and moderate dose radiation, coffee consumption and heart function, testing in long-term care facilities and COVID-19, and delirium after surgery in older adults and subsequent dementia.

Program notes:

0:42 Testing in long-term care facilities for COVIDopens in a new tab or window

1:42 Pre-vaccine phase decreased rate by 30%

2:30 Coffee consumption in ambulatory adults and heart beatsopens in a new tab or window

3:30 Mean age 39 yrs

4:30 No change in serum glucose

5:30 Previous caffeine consumption

6:31 Ionizing radiation and CVD

7:30 Use lowest dose possible

8:19 Delirium, dementia and surgery in older adultsopens in a new tab or window

9:19 Up to 6 years of follow up

10:20 Is delirium a marker?

11:20 A little bit older at baseline

12:18 End

Elizabeth: I thought that we would stay in the New England Journal of Medicine and talk about these acute effects of coffee consumption on health among ambulatory adults. This study starts with this notion -- we know this already -- that coffee is one of the most commonly consumed beverages in the world.

They were looking at this idea of caffeinated coffee on cardiac ectopy and arrhythmias, daily step counts, sleep minutes, and serum glucose levels. How did they get to this? Well, there have been previous studies and also speculation that caffeinated coffee could increase these arrhythmias and also aberrant beats of the heart, and that if you're on caffeine, maybe you move around a little bit more, maybe it disrupts your sleep, and gosh, what does it do with serum glucose? Because there appears to be a relationship with the development of diabetes.

What they did was recruited 100 participants. Their mean age was 39 years. Half of them were women and half non-Hispanic white. They had coffee consumption in these folks. They also fitted them with all sorts of devices so that they could record all of this data. They got randomized to 2 days of caffeine consumption and followed by 2 days of not caffeine consumption, and then 2 days of caffeine consumption and so on. Their primary outcome: daily premature atrial contractions. Other outcomes, as I said, step counts and sleep.

They also looked at ventricular contractions in here. What they found was that the caffeinated coffee was associated with 58 daily premature atrial contractions compared with 53 on the days when caffeine was avoided. With regard to premature ventricular contractions, there were 154 in a group when they did the caffeine and 102 in those who did not. Step count did increase to 10,646 when you drank the coffee versus 9,665 the days you didn't. You slept shorter and there was no change in serum glucose.

Rick: A couple of things. One is it's in the small group of individuals, it's 100. The question they asked I think is relatively important, because we're trying to avoid atrial fibrillation. It increases the risk of stroke, people have to take blood thinners, and so we're trying to minimize the risk factors. Does coffee contribute to that by increasing the risk of increased atrial extra beats? This study suggests that it doesn't. But, again, it's a young population and it doesn't really tell us how much coffee they really drink. It is kind of a ho-hum. I was kind of surprised -- I wasn't sure it was New England Journal of Medicine-worthy.

Elizabeth: What I want to know is why in the whole discussion they didn't talk anything about premature ventricular contractions? We did see that there was a difference in those among the caffeine consumption days and there was absolutely no discussion about that. What we know from older populations is that those are associated with a heightened risk of heart failure.

The other thing that I would like to know is, let's talk about the previous consumption of caffeine among this population they selected. Because if you picked me I have been consuming caffeine on a daily basis for decades. If you randomized me to a place where I was doing two on and two off, that wouldn't account for my caffeine consumption previous to ever entering this study.

Rick: Your points are very well taken. I'm surprised, too, that they didn't talk about the increased incidents of premature ventricular contractions. However, when you look at the totality of data, it looks like moderate coffee consumption is associated with a decreased cardiovascular risk. I agree with you. They completely kind of ignore the premature ventricular contractions. In fairness, it was a secondary endpoint.

Elizabeth: I would also just like you to comment on cardiac ectopy, just to begin with. My understanding is that everybody has this.

Rick: Exactly. That's why they used the individuals as their own control. Throughout the day, each of us has periods where we have what some people call extra heartbeats. They occur both in the upper chamber, the atrium, and the lower chamber, the ventricle, in a completely normal heart and nothing needs to be done about it.

Elizabeth: Since we're talking about the heart, let's talk about ionizing radiation and cardiovascular disease. That's in the BMJ.

Rick: Now, as a part of the routine care of individuals, they are oftentimes receiving either very moderate or low dose in radiation, mammography or a CT scan, or what's called a myocardial perfusion study -- a nuclear medicine study. Do those low or moderate doses increase the risk of heart disease?

They reviewed over 15,000 studies. They found that there were 93 that they thought were informative. They did look at the risk of heart disease -- ischemic heart disease, stroke, and heart failure -- in relationship to what's considered moderate or low dose. What they did discover is the fact it does increase the risk of heart disease, more so with stroke than ischemic heart disease.