By Denise Williams | News & Views

As a cardiopulmonary rehabilitation professional, if you could improve a patient’s outcome with just one small change, wouldn’t you do it?

It’s an achievable goal, assures Wayne Cascio, MD, FACC, who is happy to explain how and why. The key, according to the cardiologist, scientist and director of U.S. EPA Office of Research and Development’s Center for Public Health and Environmental Assessment, is as simple as making rehab participants more aware of a potential menace that often flies under the radar: air pollution.

Poor-quality air represents a potential threat to anyone exposed to it, but some people are more susceptible than others. “Some individuals having certain clinical conditions are much more at risk,” confirms Dr. Cascio, “and that population happens to be the population attending cardiac rehab (CR) and pulmonary rehab (PR).” Somber statistics offer added context to this narrative. On a global scale, 25% of ischemic heart disease diagnoses, 20% of strokes and 20% of all cardiovascular disease diagnoses are tied to air pollution exposure.

With that inherent vulnerability, Dr. Cascio believes, comes the promise of a bigger payoff — compared with society at large — when CR/PR patients learn to adapt their behavior as needed to align with the quality of air around them at any given time.

Particulates, in Particular

There are multiple air pollutants of concern — ozone, nitrogen oxides, lead and carbon monoxide among others — but what should be keeping CR/PR professionals awake at night, Dr. Cascio suggests, is particulate matter (PM). It is created, he notes, “when something burns,” such as wood, coal or tobacco. The emissions released during combustion present as particles of varying size, with the smallest ones doing the most damage. Their tiny size allows them to wreak havoc in a few different ways:

• By sneaking past the upper respiratory tract and into the lungs, where they cause inflammation
• By activating the autonomic nervous system
• By creeping into the blood, which transports the pollutants throughout the body

“Through these three mechanisms,” remarks Dr. Cascio, “particulates can have effects on blood vessel function, coagulation and heart rhythms and they can give rise to heart attacks, strokes, abnormal heart rhythms and heart failure.” Notably, he observes that approximately 50% of COPD cases worldwide are blamed on air pollution.

Keep Clear of Bad Air

More cardiopulmonary problems are the last thing an already compromised patient needs, so it’s fortunate that at-risk populations have ways to routinely protect themselves. One general tip Dr. Cascio recommends following is to avoid working out near heavily trafficked roads, where higher concentrations of PM are likely. Physical activity outside of the rehab setting is still encouraged, he emphasizes; however, “you should look carefully at where that exercise is occurring.”

More broadly, he says CR and PR patients should make it a priority to monitor the EPA’s air quality index (located at airnow.gov) daily. The metric reports air quality, from good to hazardous, on a color scale as well as on a numerical scale. “You can base some decisions — what actions you might take — according to the level of the air quality,” Dr. Cascio advises. A reading at the orange level should put someone with ischemic heart disease or heart failure, for example, on alert. “If you’re a susceptible person and you reach a certain level of the air quality index where it puts you at risk, you should probably just stay indoors,” he continues. “If you have to go outside and you’re going to be out there for a while, you can wear a fitted N95 mask. And you shouldn’t exercise outdoors on poor air days if it gets into a range where you could be at risk.”

Clear the Air With Your Patients

Having useful guidance like that is key to mitigating the risk of health effects from air pollution, but it’s only helpful if those kinds of conversations are happening between CR and PR professionals and their enrollees. Dr. Cascio points to research out of the Centers for Disease Control and Prevention (CDC) indicating that 37% of pulmonologists and an even smaller share of cardiologists — a mere 3% — open up dialog with patients on how air pollution can affect their health.

“I think it’s fair to say that most physicians, cardiologists and internists are probably not instructing their patients about any potential impact of air pollution,” Dr. Cascio laments, noting the missed opportunity to improve outcomes. EPA data bears that out, he says, with researchers demonstrating a “dramatic mortality difference” among heart failure patients, based on whether they live in areas where the average PM level is above or below national air quality standards. “If their air quality is better than the standard to which the U.S. EPA regulates, their mortality risk is actually improved by 25% over 10 years,” Dr. Cascio shares. “If you had a medicine that did that, it’d be a blockbuster!” To the contrary, where air pollution is higher, scientists have found that patients with heart failure are at increased risk of hospital readmission.

In other research, EPA shows that cardiovascular mortality rates improved by about 2% to 3% in areas where measures were adopted to improve air quality.* While that figure applies to the population as a whole, Dr. Cascio is confident the benefit would be significantly greater within the context of CR/PR. But even the population-level percentage is nothing to sneeze at, in his opinion. “To me, 2% to 3% is a great improvement,” he says, with conviction. “If you could improve the outcome of your patient by even 1% just by making them aware of air quality, that would be a great thing.”

To learn more on this topic, AACVPR members may access the recording of Dr. Cascio's webinar, "Health Effects of Air Pollution in At-Risk Populations: The Relevance to Cardiac and Pulmonary Rehabilitation," at no charge. The presentation, which was livestreamed on January 9, 2024, is available here.

References

*Corrigan AE, Becker MM, Neas LM, Cascio WE, Rappold AG. Fine particulate matters: The impact of air quality standards on cardiovascular mortality. Environ Res. 2018 Feb;161:364-369. doi: 10.1016/j.envres.2017.11.025. Epub 2017 Dec 1. PMID: 29195185; PMCID: PMC6372949.

Ward-Caviness CK, Weaver AM, Buranosky M, Pfaff ER, Neas LM, Devlin RB, Schwartz J, Di Q, Cascio WE, Diaz-Sanchez D. Associations Between Long-Term Fine Particulate Matter Exposure and Mortality in Heart Failure Patients. J Am Heart Assoc. 2020 Mar 17;9(6):e012517. doi: 10.1161/JAHA.119.012517. Epub 2020 Mar 16. PMID: 32172639; PMCID: PMC7335509.

Wyatt LH, Weaver AM, Moyer J, Schwartz JD, Di Q, Diaz-Sanchez D, Cascio WE, Ward-Caviness CK. Short-term PM_2.5 exposure and early-readmission risk: a retrospective cohort study in North Carolina heart failure patients. Am Heart J. 2022 Jun;248:130-138. doi: 10.1016/j.ahj.2022.02.015. Epub 2022 Mar 7. PMID: 35263652; PMCID: PMC9064928.

Ward-Caviness CK, Danesh Yazdi M, Moyer J, Weaver AM, Cascio WE, Di Q, Schwartz JD, Diaz-Sanchez D. Long-Term Exposure to Particulate Air Pollution Is Associated With 30-Day Readmissions and Hospital Visits Among Patients With Heart Failure. J Am Heart Assoc. 2021 May 18;10(10):e019430. doi: 10.1161/JAHA.120.019430. Epub 2021 May 4. PMID: 33942627; PMCID: PMC8200693.