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New Research Links Heart Attacks to Higher Plastic Levels in Blood
In A Nutshell
- Heart attack patients had detectable plastic in their blood far more often (84%) than patients with stable heart disease (40%) or normal angiograms (32%).
- Blood drawn from the artery involved in a heart attack showed the highest plastic concentrations and the widest variety of plastic types.
- Smoking history was the single strongest predictor of plastic detection, even after accounting for pollution exposure and other heart risk factors.
- The findings show an association, not proof that plastic exposure causes heart attacks, and researchers are calling for larger studies to investigate the link further.
Blood collected from the coronary artery involved in an active heart attack contained something researchers weren’t expecting to find in large quantity: plastic. Tiny fragments turned up far more often and in greater amounts in patients suffering the most severe kind of heart attack than in anyone else tested.
Cardiologists in Italy examined blood from 61 patients undergoing procedures for suspected heart disease, drawing samples from a peripheral artery at the procedure’s access site and from inside the coronary arteries. Nearly 84% of patients mid-heart attack had detectable plastic in that blood, compared with 40% of patients with more stable, chronic heart disease and just 32% of patients whose angiograms showed normal coronary arteries. Heart attack patients also carried a wider variety of plastic types and higher overall concentrations than anyone else in the study.
Published in the European Heart Journal, the study also found that smoking and higher exposure to fine-particle air pollution were associated with a greater likelihood of detecting plastic, hinting at how the particles might get into the bloodstream in the first place. The findings don’t prove plastic causes heart attacks, but they add a notable data point to a growing conversation about whether the plastic surrounding daily life is turning up somewhere it was never meant to be.
How Scientists Detected Plastic in the Blood of Heart Attack Patients
Between February and April 2025, cardiologists at two Italian hospitals enrolled patients scheduled for a coronary angiogram, a standard procedure where a thin tube is threaded into the heart’s arteries to check for blockages. Nineteen patients were in the middle of a STEMI, medical shorthand for the most severe heart attack type, usually caused by a complete or nearly complete coronary blockage. Twenty patients had chronic coronary syndrome, meaning narrowed arteries that cause chest pain but aren’t an emergency. Twenty-two patients served as a comparison group whose angiograms showed normal coronary arteries.
Doctors drew blood from two points during each procedure: a peripheral artery and directly from inside the coronary arteries, a sampling approach rarely used in prior research. Most studies on plastic in the body have relied on blood drawn well away from the heart or on tissue removed during surgery, a snapshot after the fact. This study isolated blood actively moving through the arterial system at the moment doctors were treating a blockage.
Two independent detection methods were used: one that breaks samples down chemically to identify polymer signatures, and one that uses infrared light to confirm particle shape and composition. Researchers also ran extensive contamination controls to reduce the chance that the plastic came from medical or laboratory equipment rather than the patient’s own blood. Several plastics familiar from packaging turned up, but polyethylene, used in bags and bottles, showed up in 97% of patients who tested positive.
Plastic in Blood Was More Abundant and More Diverse in Heart Attack Patients
Heart attack patients tested positive far more often, and also carried a wider mix of plastic types, a median of three polymers compared with zero to two in the other groups, with concentrations highest in blood drawn from the artery involved in the heart attack. These patients also had significantly higher levels of two blood markers tied to inflammation, both measured in that same coronary blood. The two findings occurred together, though the study couldn’t determine whether the plastic contributed to the inflammation or the reverse.
In the paper’s discussion section, the authors describe their work as providing “in vivo evidence of MNPs in arterial coronary blood samples,” meaning proof gathered from blood still moving through a living patient rather than tissue examined after the fact. MNPs is medical shorthand for micro- and nanoplastics.
Smoking Emerged as the Strongest Predictor of Plastic in the Blood
Researchers cross-referenced each patient’s home address with air quality monitoring stations, tracking same-day and average two-year pollution exposure. Smoking history and higher long-term exposure to fine-particle air pollution both showed a strong link to plastic detection on their own. When researchers combined every factor, smoking stood out as the only one that independently predicted whether plastic turned up in a patient’s blood. Patients with a smoking history had nearly six times the odds of testing positive, though the estimate carried considerable uncertainty given the small study size. Every patient who both smoked and had high long-term pollution exposure tested positive for plastic, without exception.
What the Plastic and Heart Attack Link Means, and What It Doesn’t
Sixty-one patients is a modest sample size, and the authors are upfront that their findings point toward a pattern worth investigating further rather than proof that plastic causes heart attacks. Correlation and causation are easy to mix up here. It’s possible that whatever makes someone’s arteries vulnerable to a heart attack also makes it easier for circulating plastic to lodge in that same arterial tissue. The study wasn’t designed to rule that out.
Still, the pattern gives researchers reason to investigate further in larger studies. Smoking’s role as the strongest predictor lines up with an explanation the researchers propose: cigarette smoke may damage the lining of the airways and lungs, making it easier for inhaled plastic to slip into the bloodstream, though the study didn’t prove this mechanism. A companion editorial published alongside the study notes that plastic production has grown from 1.5 million tons in 1950 to roughly 500 million tons today. The findings raise a question that larger studies will need to answer: whether plastic exposure contributes to heart risk, or simply travels alongside other environmental and lifestyle hazards already known to harm the heart.
Disclaimer: This article is intended for general informational purposes and is not a substitute for professional medical advice. Anyone with concerns about smoking, chest pain, or heart health should speak with a qualified health care provider.
Paper Notes
Limitations
The research team acknowledged several constraints on their findings. With only 61 patients split across three groups, the study is too small to draw firm conclusions about cause and effect, and the authors describe their results as exploratory rather than confirmatory. Patients with non-STEMI heart attacks, a milder subtype, were excluded because their underlying causes are more varied, so the findings apply specifically to the most severe form of heart attack. Blood collection methods differed slightly between the STEMI, chronic, and control groups, reflecting standard safety practice rather than a study design flaw, though peripheral blood samples were collected the same way across all patients as a check. The study only measured plastic exposure through air pollution and smoking; other likely sources such as food, water, and packaging weren’t directly assessed. Researchers also had incomplete data on how long former smokers had quit, which prevented them from studying whether quitting reduces plastic levels over time.
Funding and Disclosures
The authors reported no conflicts of interest. The research was supported by Italy’s National Plan for Complementary Investments, a European Union Next Generation EU grant, Italy’s Ministry of Health through IRCCS MultiMedica, and a research grant from the DigiCardioPaTh PhD Program.
Publication Details
The study, “Micro- and nano-plastics in the coronary circulation and air pollution exposure in ischaemic heart disease presentation,” was authored by Pasquale Paolisso, Lucia Scisciola, Marta Belmonte, and colleagues, with senior authorship from Giuseppe Paolisso and Emanuele Barbato. It was published in the European Heart Journal in 2026 (DOI: 10.1093/eurheartj/ehag447). An accompanying editorial, “Nano- and microplastics in the cardiovascular exposome: a new frontier in environmental risk,” was written by Andreas Daiber, Marin Kuntic, and Thomas Münzel of the University Medical Center of the Johannes Gutenberg-University in Mainz, Germany, and published in the same issue (DOI: 10.1093/eurheartj/ehag383).
