Something In the Air: A New Risk Factor for Cardiovascular Disease

In episode 13 of the CardiOhio Podcast, we learn about a newly emerging risk factor for cardiovascular disease, air pollution,  from a local expert, Dr. Sadeer Al-Kindi from University Hospitals in Cleveland.  We review the sources of air pollution in both westernized and developing countries, discuss the evidence for a causative role in development of cardiovascular disease, as well as potential pathophysiologic mechanisms.  We conclude by discussing strategies to mitigate risk both at the societal and individual levels.

For more information:
Air Pollution and Cardiovascular Disease: JACC State-of-the-Art-Review
The "Heart" of Environmental Justice

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Transcript

0:04

Welcome to the Cardio Ohio Podcast, a production of the Ohio Chapter of the American College of Cardiology. This is Can Greyal in Columbus, Ohio. This is Ben Allen Cherry Cardiovascular Imaging fellow from Cleveland, Ohio. More information on the podcast, including past episodes, is available@ohioacc.org. And now for today's,

Kanny 0:28

So welcome back to the Cardio Ohio podcast. We have a very interesting and I think, timely topic to discuss today, and we're very pleased to have an expert with us to discuss our topic of. Air pollution and cardiovascular disease. I'd like to welcome from Cleveland Dr. Sadir Aldi, who is co-director of the Center for Integrative and Novel Approaches in Vascular and Metabolic Disease at University Hospitals in Cleveland, and he's also an associate professor at Case Western. Sadir. Welcome to our podcast.

Sadir 1:04

Thank you so much for the invitation and for really focusing on this very important topic.

Kanny 1:12

Absolutely. And of course, I'd also like to go ahead and welcome my longtime co-host also from the North Shore of Ohio. Ben Allen, cherry Ben, welcome back.

Ben 1:22

Thanks a lot Candy. We're, we're excited to have Sadir on. Sadir was one of our senior residents when I was an intern, so we've been learning from him now through Jack Journals about this this unique topic. So Sadir I'll just kind of get us started. We usually start with like a little background so people can get to know who you are. Can you just tell us. A little bit about, you know, med school residency and, and what your practice looks like today, how you break it up between research, outpatient, inpatient, et

Sadir 1:51

cetera. Yeah, thank you. So I actually have done my medical school in Wild Cornell and Qatar and I came to the US in 2013 where I started doing internal medicine residency at University hospitals in case Western Reserve. And this was followed by cardiology fellowship. And I took. As part of the A B I M research pathway, it took a couple of years where I kind of trained myself on some biostats and ape methods. And I also did some bench research in translational immunology. And then this was followed by an advanced imaging cardiac CT and m r training at university hospitals, which I completed in 2019. And since then I've been on faculty. At u in, in case Western. I do a lot of my time is spent at least the clinical time is spent between prevention and I focus on vascular and metabolic disease. So we do quite a bit of diabetes prevention and, and cardiovascular prevention in patients with type two diabetes. And Theia. But also I do quite a bit of advanced imaging and I merge the utilization of population level imaging using calcium scoring and other type of coronary imaging to guide preventive strategies and, and provide some precision care. My research has focused mainly on kind of intertwined areas of really non-traditional risk factors for cardiovascular diseases. If you wanna put it under one umbrella, and that includes population immunology and understanding the immune phenotype and the population level, but also how does it intersect with radiomics and understanding the harnessing some of the. Detailed information from CT and MR. And echocardiograms to guide risk. But you know, how do these really in a global scale, intersect with the natural built and social environment and identify people and how can we phenotype them better and target some of the environmental exposures? So this is a nutshell, kind of all encompassing, a global cardiovascular, preventive strategies and, and risk stratification.

Ben 4:10

So that was that was super impressive. Sadir I can tell each day is probably not the same for you, so that's, that's awesome. When we start picking themes for this podcast, we try to relate it to the, the everyday clinician, the cardiologist and member of the cardiovascular team. And the reason why we wanted to highlight some of your work, and I know you work in many disciplines, was You know, we think air pollution is timely. Now we're, we're understanding a bit more of this effect on society and yourself, along with Dr. Roger Gopalan and other authors from from wrote a, a very timely 2018 review on on air pollution and cardiovascular disease and its effect, and what we as clinicians need to know about it. Can you just for the audience describe how you define air pollution, cardiovascular disease, and what are the main players in that relationship?

Sadir 5:03

Yeah. So it's, it's complex to say the least. I think the background, just to simplify it, and I think everything we're gonna talk about today is a lot of it is conceptual framework because. There's a lot, probably more that we don't know than, than we know. So air pollution in general is described into two different kind of categories, big categories. There is gas, yes air pollutants, and there is. Particulate air pollutants, and you can think of them as solid matter that is suspended in the air. And amongst those, the, the, the most important one is probably particulate matter that is small enough to be inhaled, and that's what we call PM 2.5 or matter less than 2.5 micron in size. And these particles, they are composed of very different kind of mixtures. And it turns out that these mixtures vary depending on the location, depending on the sources and things like that. But these particulate matters, they can be inhaled in the lungs and they can result in variety of different kind of downstream effects, both pathologic and physiologic. And. And other kind of effects that lead to health hazards. And just to give you a perspective of how we usually kind of, what, what are the numbers that we refer to and so on and so forth. We typically refer to concentration of exposure. And that can be done either acutely, you know, over hours, days, two months, or it can be done kind of annually. And Each geographic area or entity or authority, they prescribe a specific standard. So in the United States, for example, our standard by the EPA has been annual exposure of about 12 microgram per meter cube over. A year. And that may be a number that doesn't mean anything to people, but just to give you a perspective in the us, our levels and, and it varies a little bit, but overall has been in the seven to eight to nine kind of microgram perimeter Cuban. It has since the CLEAR Act Decades ago, things have really improved significantly, where the levels used to be much higher. But when you look at other countries you know, countries like India and specifically urban cities like New Delhi other cities like Beijing, and even a lot of the cities in the Middle East, including Dubai, Doha, and, and other things it's not unusual to to have daily levels that exceed 100 microgram per meter. Which is almost 10 times to 15 times what we experience here in the West world. So I think that's, that's something that we kind of are starting to learn about the effects and what is really the relationship, at least epidemiologically and ecologically, what is the relationship between the concentration of exposure and downstream health impact and the global burden of disease. As you know, they estimate using different mathematical models. The most recent adoration of, of the effect that we kind of estimate is just particular matter exposure. And environmental pollution in general can cause about 9 million deaths, most of which are due to particular matter and most of these deaths globally. Every year are attributed to cardiovascular disease. So there is significant, you know, it's a significant problem although some of the concentrations are low, but think of them as your breathing air every second, right? So throughout your life. So there is a significant amount of exposure over time.

Kanny 8:49

you mentioned how in the US our levels are generally acceptable, but. My understanding is that there can still be quite a bit of variation within any municipality. Correct? For example, if you live near a highway your local exposure could be much higher than someone who lives in a rural area, even if the overall population exposure is acceptable.

Sadir 9:10

That's very, that's exactly right. And, and not just that it, it turns out that for a variety of reasons, there is a lot of inequity when it comes to exposure. So we have recently just showed that if, if you look at people who live in Red Line neighborhood these are historically red line neighborhoods. They have much higher exposure throughout both gas and. Particular matter exposure. So not only the location where you live in the proximity to airway to highways and, and things like that, but also it turns out that there is kind of significant geographic distribution differences that may be related to historical kind of identification of areas that have been impacted by, policies that have been inequitable. So within the United States, there is significant distribution effects, but it, it still is. For the most part it still is acceptable. Now the question is, what is, what is the definition of acceptable and why did the e p a, for example, decided to do 12 microgram perimeter cube? And we're learning more and more that there's really no safe. Threshold. This threshold is somewhat arbitrary and we have gone under it, which is fantastic. But given the building of the data, the building of the evidence, over the past three, four decades, we are learning that there's really no safe threshold. This is exactly like smoking, right? There's no safe amount of smoking. So, The World Health Organization just recently, in the past year or two, they have lowered their their threshold to about five. So now the e p A is starting to follow, so there's no safe limit. And the effect on cardiovascular disease are probably the most prominent. But we also see additional chronic health effects, including asthma, respiratory disease in general lung cancers and other, we're realizing that there's also other things, including Alzheimer's disease dementia, vascular disease, kidney disease, and other things that are a little bit more emerging these days. So us as cardiologists and practitioners of cardiovascular disease. It's important to understand how does air pollution impact cardiovascular health and what is the downstream effects looking like and what diseases are really attributable to two environmental exposures. And this is an area of active investigation. We're still learning about this. Most of these particles, they're not absorbed into the blood. So the conceptual framework right now is that these go into the lungs and reside in the lungs. They cause local inflammation, local signaling that leads to a lot of systemic effects that lead to thrombosis, systemic inflammation endothelial dysfunction autonomic imbalance and autonomic dysfunction. And that leads to a lot of the downstream effects that lead to diabetes, which we know is, is probably causal. Air pollution is causal and diabetes and insulin resistance elevation and blood pressure and hypertension. And then probably plaque destabilization and atherosclerosis progression leading to fatal and non-fatal kind of atherosclerotic events. We're also learning about heart failure being impacted by this because we see in animal models that there's fibrosis. And we see in human studies that there is a direct relationship between exposure and, and, and heart failure events and so on and so forth. So it's a lot to be kind of to, to be deducted from all these studies that are emerging. And every day there is a new study that helps us move the needle a little bit to understand this. And it's important to say that these, a lot of these studies are actually high level studies that are done using either. Animal models or randomized human studies of intervention or exposure that helps us understand the pathophysiology.

Kanny 13:14

Sadir. One thing you touched on a little bit in your review paper is, distinguishing, external air pollution from household air pollution. And also, potential natural sources like wildfires, which has been in the media, the last few summers about the air quality related to wildfires. How do those rank in contribution to the burden relative to like traditional, what we consider like air pollution from burning fossil fuels.

Sadir 13:39

Yeah, no, I think that's a great question. And it, it, it really depends on the location. I think we don't use a lot of coil coal burning here and kind of traditional fossil fuel for cooking and indoor and you know, smoking is, is, is, is limited but still. It's prevalent, not like in other countries where there is hookahs and other type of smoking that results in significant emissions. So the household kind of air pollution has direct and, and significant impact. And I think it depends on the geographic area. If you go to you know Africa and, and a lot of the countries in Africa where the household air pollution is a bigger. Maybe as big, maybe a bigger contributor to health outcomes compared with ambient air pollution. While in the west world, we see a lot of the countries that have less household Pollution and more of ambient air pollution impact so let me just take a step back and just to see how we do these studies in general. How can we understand the impact of air pollution on myocardial infarction, for example? And the problem is we don't actually. Have a way to measure everybody's exposure, right? So for the most part, when you look at epidemiologic studies, we use satellite imaging combined with some of the models, statistical models, and adjusting for some of the ground monitors to estimate somebody's exposure in ambient air. But the problem is we don't have a good method at least at the population level, to estimate what is the exposure due to household air pollution. And that's one of the limitations in the present literature. We have studies that compare the health effect of. Household air pollution compared with the ambient air pollution. Right.

Ben 15:38

Just, just switching then, we have a lot of people who are healthcare contributors and healthcare providers listening in and, and what do you think, are healthcare's contributions to this problem? We often think of like seeing patients who are affected by it, but where do you see healthcare factoring in and what do we, what are we doing to contribute to the problem?

Sadir 16:00

Yeah, no, that's a fantastic question. Let me just give you a perspective of how, if you if you were to collect all healthcare in the world and make it a country, right, the exposure, the, the emissions, the greenhouse gas emission. From all of the healthcare in the world, it would become the fifth largest contributor to greenhouse gas emissions. And it, it turns out that this is a significant problem. I mean, you saw, you see a lot of these pictures and photos of, of masks being thrown out, especially with PPEs after covid. All of that contributes really to environmental pollution, both directly and indirectly. So you can think about, you know, how much plastic do we throw out if you go to the cath lab? How much, how many needles do we use and how many, you know, these kits that come in with a lot of plastics and things like that, and how much do we utilize how much electricity are we, are we using, you know, you go to the operating rooms and they're freezing cold, right? How much does that contribute to the healthcare emissions? So it's, it's a significant problem. And I think this is gonna be a, a, a core kind of focus of multiple organizations in the next decade or two is to how do we, how do we You know, move the needle in terms of improving sustainability, environmental sustainability specifically for healthcare, but also at the individual level, are there incentives for electrical vehicles? Can we pool cars? Can we reduce our intake of non-sustainable food? For example, meatless Mondays and other things. So there's a lot of things that can be done both at the individual level and also at the organizational level. And we also have to think a little bit more creatively about how can we reduce emissions from unnecessary patient travel, for example. So I would direct you to a recent paper in JAK advances that utilized data from. Almost like a national data from remote monitoring of implantable devices. And they showed that just by moving this small thing, moving it patients from in, in-person visit for device interrogation device monitoring to a remote device monitoring. That had resulted in significant reduction in emissions from patient traveling significant reduction in utilization of, of paper, for example significant cost saving so we have to start thinking about how can we incorporate the environment, the environmental health, into our interventions and how can we quantify some of these effects in, in randomized trials and studies in the future.

Kanny 18:47

So, Sadir, before we talk a little more about what we can do individually as well. I just wanted to clarify one question about the pathogenesis. Is it my understanding that, the expos, the, the chronic exposure to pollution can lead to both chronic, atherosclerotic disease through, the various mechanisms you outlined, but does it also a act as a trigger for acute events like, for example, an acute

Sadir 19:14

mi. Yeah, I think conceptually right now, we know that air pollution can lead to progression of atherosclerosis. And it leads to kind of acute mi, both fatal and non-fatal. So the conceptual framework is that you have chronic exposure that leads to pathogenesis, progression of atherosclerosis in the vessel wall, and then you have an acute destabilization of the plaque. Which could be from an acute spike in in air pollution daily or hourly. But it could also be from a traditional kind of risk factor, right? So you have acute increase in in blood pressure, cocaine use and other things that can help destabilize f. Preexisting atherosclerosis, which has been potentiated by air pollution. So you know, we, we can't forget about the traditional risk factors and how they interact with the air pollution effects. And that's where, you know, you become, you can become a little bit more susceptible if you have a preexisting atherosclerosis to the health effects of, of air pollution.

Kanny 20:18

That makes a lot of sense. So we just wanted to use the last five to 10 minutes to talk about, strategies to address this. Now that we're much more aware, thanks to you and your colleagues about the connection it sounds like you can kind of divide, the potential strategies and to those that are, community and societal and, and maybe some individual strategies as well. We don't have time to talk about all of the, obvious strategies that are out there at the national and community and legislative level. But what do you think? There's a couple that you would think would be most important that we can focus for example, as the ACC nationally can advocate for to help start to address the problem and then we can move on to some of the individual things as well.

Sadir 21:06

Yeah, I think well, every one of us has has an environmental footprint, right? So as, as practitioners, as healthcare workers, as even as patients, right? Every one of us have have an environmental footprint, and it's up to us to think about how we can improve and reduce our environmental footprint to achieve NetZero emissions. So that's one that is, that can be done on daily lives. You know, like I said, the commute to work, the type of things, the consumption, the type of food that you eat, and how much environmental sustainability you, you, you desire and you want, and you can experience in your life and you practice in your life. But I think at the, at the national level, from a societal standpoint, I think there is a need to kind of come up with strategies to reduce healthcare kind of emissions in general, improve healthcare sustainability. But also how can we educate and teach and include some of the environmental cardiology You know, sessions and objectives and understanding and the current knowledge into fellows education the career education, and how can we really propel the, the, the field forward by educating the next generation of cardiologists in all healthcare. Professionals in terms of fighting environmental pollution, identifying problems that are related to cardiovascular disease and, and, and the risk that intersects between the two. And I think that's something that will be probably, like I said, it's gonna be. Probably the focus of the next century. And we started to experience that in the United States with acute climate events and weather events including more increased rate of flooding and, and fires and, and other things and, and some geographic areas. This becomes really something that is very important to talk about with your patients at the, at the bedside. But there's a another thing that really we have to think about. And, and as you know, the a h a, for example, comes up with life essentials every so often and more. More recently, they came up with Life Essential eight, where we, they added sleep into out, into ideal cardiovascular health. And one of the targets for, for ideal cardiovascular health. And there has been very limited kind of Talk about how can we improve the environment, improve the social environment, improve the, the, the built environment and the natural environment to optimize cardiovascular health. So when we start to talk and open up these discussions and start to talk about how can we. Target the environment to reduce cardiovascular disease, then only then we can start to think about how some of the methods and some of the tools that we have in our hands to reduce, reduce cardiovascular disease in general.

Ben 24:05

Yeah, and just to end on this note with one last question, Personal measures, sometimes clinicians will, will now want to bring it to the patient level about what, what patients and and healthcare providers can do on personal level to kind of reduce this risk. But from that end, on the personal measures, Do you think we learned anything from the Covid 19 pandemic where, where people were masked a lot, there was a lot more care, I guess you can say for for environmental protection in the, in the sense of wearing masks, et cetera. Do, do you think we learned anything from that or have you, has your group gained any insight from that to inform our patients on a personal

Sadir 24:48

level? Yeah, and I think let me address the first part of your question about the personal what I call mitigation and adaptation, right? So we have to adapt to the environment that we live in regardless, because as you said, you know, it's gonna take years to actually change the exposures. And what we know so far is, I, I would think about, you know, what are some of the tangible things that we, as clinicians can think about when it comes to our patients. And I can think of two things. One is how can we incorporate the environmental exposure into our risk prediction? Right? We've known that air pollution is associated with cardiovascular disease events, regardless of your social determinants of health and your traditional risk factors, and the degree to that expo, the degree to that risk is really not small. When you talk about effect size of. You know, every 10 microgram increase in air pollution associated with about 20 to 25% increase in hazards of death and patients undergoing p c i. This is not a small risk. This is equivalent to some of the other risk factors that we experience in exposure. So, You know, can we incorporate environmental risk factors? And can we quantify them, put them in the electronic medical records and, and, and start to incorporate them into our risk calculators? Is, is it an important question? And this is the focus of my you know, fo main focus of my research. The second thing is really how can we mitigate and how can we reduce exposure at the individual level, especially for patients who are vulnerable. Like we said, patients the patients that we see in clinic are patients with cardiovascular disease. They are susceptible significantly more susceptible than others for harmful effects of air pollution. So some of what are some of the kind of mitigation strategies at the individual level. And what we've learned is that personal air cleaners, for example, portable air cleaners that you can put at home with HEPA filters, they can reduce air pollution by about 90% or so. And, and randomized trials, mechanistic, randomized trials, this has been shown to reduce blood pressure. By about four millimeter mercury, which is, you know, equivalent to what you see with some of the blood pressure medications. It has been shown to reduce inflammation, it reduces insulin resistance and so on and so forth. But there are things like you, like you mentioned, you know masks and specifically at 95 masks and maybe staying indoor and maybe, you know, avoiding some of the traffic areas and, and, and so on and so forth. And I would expand that not only to air pollution, but also to the temperature effects, right? I mean, in, in Cleveland we have really cold days and we've been taught in medical school that cold can trigger cardiac arrests, and we've seen that in clinical practice as well. So I. Avoiding polluted areas, avoiding suboptimal kind of weather. Suboptimal environmental kind of factors becomes an important factor to kind of adapt to the environment and maybe staying indoors when it's cold. When you're staying indoors, when you have And AQI Air quality Index, that's high staying indoor when you get an alert about poor environment conditions, When it comes to covid, what we've learned so far is that Covid led to. Reduction in air pollution in general, specifically in urban cities where there were lockdowns and so on and so forth, which had, you know, increased again, back to almost baseline with the recovery of, of, of life and, and activities and human activity in general. So it gets In terms of health effect, it's really difficult to tease out because on one hand we had increased risk because of covid, increased risk of events, and on the other hand, we had lower exposure of lower concentration of, of air pollution you know, metrics and so on and so forth. So my personal opinion is that we're not gonna learn much from that experience when it comes to the exposure effects. But I think we have enough. Right now to say that air pollution is causal when it comes to cardiovascular disease, majority of types of cardiovascular disease, and this is something that we have to target very soon.

Ben 29:11

Yeah. Thanks Sadir. You know, I think that's a fitting end because it shows just how difficult the research in this area is, but we are glad you and your team are taking this on. And, and just wanna thank you on behalf of Kenny and I because when we picked this topic, we we understood how difficult it is to, to kind of educate. People on this because it's on a macro level, but I think you've done a, an awesome job just just sharing your work and, and the implications for the future. So I wanna say thank you for coming on and, and we greatly appreciate

Sadir 29:43

it. Thank you so much for both of you and for Ohio, a c c for hosting this important topic

29:50

Thank you for joining today's podcast. For more information about the speakers or the topics, please go to Ohio acc.org,