Levels of microplastics and nanoplastics (MNPs) in coronary blood were higher in patients with a STEMI than those with chronic coronary syndromes (CCS) or in controls, according to a cross-sectional study published July 14 in the EHJ. Furthermore, the detection of MNPs frequently co-occurred with elevated inflammatory biomarkers, higher fine particulate matter with diameters ≤2.5 μm (PM_2.5) exposure and smoking, suggesting a possible association between environmental factors and coronary artery disease (CAD).

In this investigator-initiated, multicenter study, 61 patients undergoing coronary angiography for suspected CAD between February 2025 and April 2025 were stratified into three groups: patients with STEMI undergoing primary PCI (n=19), patients with CCS (n=20) and controls with normal coronary arteries (n=22). The patients had a mean age of 64 years and 28% were female.

Pasquale Paolisso, MD, and Lucia Scisciola, et al., quantified MNPs in coronary and peripheral blood using pyrolysis-gas chromatography-mass spectrometry and laser direct infrared spectroscopy. Air pollution exposure data were collected for the day of the invasive procedure (acute exposure) and the previous two years (chronic exposure). The primary objective was to compare the burden of MNPs in the coronary blood of patients undergoing invasive coronary angiography for suspected CAD.

Results showed that MNPs were detected in 84% of STEMI patients, 40% of CCS patients and 32% of control patients (p=0.002). STEMI patients had a higher concentration and greater polymer diversity [median of three polymers (interquartile range, 2-4), p<0.001], with polyethylene as the predominant polymer (97%). Notably, the same polymers were consistently identified in coronary and peripheral blood samples of individual patients, with the highest concentrations in coronary blood (p<0.001).

Additionally, STEMI patients had higher interleukin-6 and tumor necrosis factor-α levels (p≤0.006) and greater PM_2.5 exposure (p≤0.012). MNPs were detected more frequently in smokers and those exposed to PM_2.5 >15 µg/m³ (p=0.006), with all patients having both factors showing detectable MNPs (p<0.001). Multivariable analysis showed that smoking history was the only independent predictor of MNP presence (odds ratio, 5.69; p=0.023).

"The present study addresses an urgent and emerging public health issue by investigating the association between MNPs, PM_2.5, and smoking in CAD, both in the acute and chronic settings, potentially amplifying their damaging effects on cardiovascular health," write the authors. They emphasize the urgent need to "shift from isolated risk factor management toward comprehensive environmental health strategies, moving from 'patient-level' to 'population-level' preventive measures."