Heart transplant recipients are particularly vulnerable to air pollution exposure, according to research published today (December 9) in the Journal of American College of Cardiology.
More than 2,000 heart transplantations are performed in the U.S. annually, and despite medical advancement, post-transplantation mortality is high, reaching 50% by 11 years after surgery.
Researchers from the American College of Cardiology conducted a study from a total of 21,800 patients from the United Network for Organ Procurement and Transplantation Network who underwent heart transplantation between 2004 and 2015.
The researchers analysed the patient’s residential post codes in order to determine air pollution exposure levels.
They compared the PM2.5 levels in the air of each patient’s postcode against the U.S. National Ambient Air Quality Standards.
The researchers found that 21.9% of heart transplant recipients were living in areas where PM2.5 levels exceeded U.S. clean air limits.
Heart transplant recipients who had long-term exposure to air pollution over several years had a 26% heightened risk for mortality due to infection for every 10 g/m3 increase in PM2.5 levels.
After a follow-up five years later, 23.9% of patients had died.
Air pollution exposure resulted in inflammatory responses and increases in blood pressure and insulin resistance, as well as a weakened immune system.
Sanjay Rajagopalan, MD, professor of medicine at Case Western Reserve University School of Medicine and the study’s senior author said: ‘Given the fact that organ transplantation adds a tremendous cost to society, we had an interest in understanding if previously unknown environmental detriments adversely affected the outcomes of these patients.
‘Long-term exposure to air pollution appears to pose amplified risks for heart transplant recipients.
‘We found an association between PM2.5 and mortality in these transplant patients.’
C. Arden Pope II, professor of economics at Brigham Young University added: ‘This study makes an important contribution to our understanding of the health effects of air pollution.
‘It used a straightforward approach to evaluate the health effects of air pollution in a unique cohort of individuals in a vulnerable health state.
‘It provides intriguing evidence that exposure to air pollution substantially contributes to mortality risk in cardiac transplant patients.’
In related news, hundreds more people have heart attacks, strokes or asthma attacks on days where air pollution levels are high, according to new research by Kings College London and UK100.
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