A new study has found microplastics in the blood of most severe patients
Italian researchers have uncovered a striking association between tiny plastic particles circulating in coronary blood and the most dangerous form of heart attack.
The study, conducted at institutions in Rome, examined roughly 60 adults and discovered that microplastics and nanoplastics were present in approximately 84 per cent of patients who had suffered a STEMI heart attack.
By contrast, only 32 per cent of control subjects with healthy coronary arteries showed detectable plastic contamination. Those who experienced severe cardiac events not only had plastics more frequently but also at greater concentrations and in more varied forms.
Polyethene, commonly found in everyday packaging materials, emerged as the most prevalent plastic type identified in the samples.
The findings contribute to mounting scientific interest in how environmental pollutants may affect cardiovascular health.
What is STEMI heart attack?
STEMI, or ST-segment elevation myocardial infarction, represents a medical emergency requiring immediate intervention. The severe cardiac event occurs when a coronary artery becomes suddenly obstructed, typically following plaque rupture and subsequent blood clot formation.
The blockage prevents blood from reaching portions of the heart muscle, causing potentially fatal damage.
For their investigation, the Italian team recruited participants who were undergoing coronary angiography, a procedure enabling physicians to examine the arteries supplying the heart.
Subjects were divided into three distinct categories: those who had experienced a STEMI, individuals with chronic coronary syndrome where arterial narrowing had developed gradually, and control participants whose heart vessels appeared normal.
Using sophisticated laboratory methods, researchers measured both the types and quantities of plastic fragments present in blood samples taken directly from the coronary circulation.
Participants with detectable plastic particles also exhibited elevated inflammatory markers in their coronary blood, including interleukin-6 and tumour necrosis factor-alpha.
"This adds to the evidence that microplastics can lead to localised inflammatory reactions, which can raise the risk of heart attack due to plaque rupture," says Joyce Oen-Hsiao, MD, a cardiologist at Yale Medicine in New Haven, Connecticut, who was not involved in the study.
Nicholas Leeper, a professor of surgery and medicine at Stanford Medicine in California, noted the research builds upon earlier work from 2024 that identified plastic particles within carotid artery plaque.
"These new findings extend the picture from tissue and plaque findings to the coronary circulation itself, showing plastics can reach the blood supplying the heart," says Dr Leeper.
However, he cautioned the observational nature and limited size of the study mean it cannot establish that plastic particles actually triggered cardiac events.
The investigation also explored environmental factors that might explain how plastics enter the bloodstream.
Cigarette smoking emerged as an independent predictor of microplastic detection, whilst long-term exposure to fine particulate air pollution showed similar associations.
"Smoking may make this easier still, by damaging the lung's protective lining and impairing its natural clearance mechanisms, so it appears to act not only as a source of toxins, but as a vector that helps plastics enter the circulation," says lead author Emanuele Barbato, a professor at Sapienza University of Rome.
Despite these findings, experts urge the public not to panic. The research did not demonstrate that plastic particles directly cause heart attacks.
Established cardiovascular advice remains paramount: avoiding tobacco, limiting indoor pollution sources such as wood-burning stoves and heavy cooking fumes and reducing unnecessary plastic use where practical.
