Microplastics linked with heart attacks in new Italian study
- John McNeil, MD
Another interesting study from the same Italian group that published the landmark NEJM article in 2024 that associated microplastics in carotid atheromas with worse cardiac outcomes. In this study of patients presenting for left heart catheterization, higher levels of microplastics were found in patients having an active heart attack (STEMI) compared to those with either stable coronary artery disease or no coronary artery disease. Smoking (which leads to inhalational plastic exposure from plastic cigarette filters, microplastics in tobacco, and damaged lung epithelium reducing protection) and fine air particle pollution were also linked with microplastics in the blood.
Appears to be a very robust study with strict collection protocols, blank sampling, and subtraction of baseline contamination levels from results. Both pyrolysis-gas chromatography-mass spectrometry and laser direct infrared spectroscopy were used for plastic analysis.
Polyethylene was the most frequently observed plastic type, and many medical catheters are also made of polyethylene - would be interesting to know what the catheters used were made of. This also could partly explain why higher levels were generally found in the coronary samples than the peripheral samples - more time in transit through a plastic catheter.
It’s not surprising that the inflammatory markers tested (TNF-alfa, IL6, etc.) were higher in the coronary circulation than the peripheral blood, as most of the inflammation and angriness is likely from the heart. But unless the coronaries are also actively shedding microplastics during a STEMI I’m not sure if I can wrap my head around why microplastics levels are higher from coronary blood than peripheral blood. It takes blood less than 10 seconds to transit the coronary circulation so you would think there would be rapid equilibration.
But all in all this is a quite compelling study that further strengthens the association between microplastics and cardiovascular disease in humans.