Italian scientists recruited 257 people with carotid artery disease,where fatty plaque deposits restrict blood flow to the brain. Microplastics lurked in the plaques of about 60 per cent of patients.
Three years after undergoing surgery,20 per cent of the patients with microplastics in their arteries had died,or suffered a stroke or heart attack.
Only 7.5 per cent of patients free from microplastics suffered the same fate.
Once the scientists controlled for other risk factors,they put the people with microplastics in their arteries at 4½ times greater risk of heart attack,stroke and death.
The study spurred influential US public health expert Dr Philip J Landrigan to call for single-use plastics to be ditched.
Finding microplastics in plaque was a breakthrough discovery in itself,which raised urgent questions,he said.