Heart attacks may be caused by infections, finds study
What's the story
A groundbreaking study by researchers from Finland and the UK has suggested that myocardial infarction (heart attack) could be an infectious disease. Published in the Journal of the American Heart Association, the research shows that certain bacterial biofilms, which can lie dormant within arterial plaques for years, may be the infectious trigger for a fatal cardiac event. The research challenges the traditional understanding of heart attacks and opens new possibilities for treatment, diagnosis, and even vaccine development.
Biofilm discovery
Viral infection or another external factor could activate bacterial biofilm
The study found that atherosclerotic plaques in coronary artery disease could contain a gelatinous, asymptomatic biofilm formed by bacteria over years or even decades. This biofilm protects dormant bacteria from the patient's immune system and antibiotics as they can't penetrate its matrix. A viral infection or another external factor could activate this biofilm, leading to bacterial growth and an inflammatory response.
Inflammatory impact
Inflammation can lead to clot formation and trigger heart attack
The inflammation caused by the activated biofilm can rupture the fibrous cap of the plaque, leading to clot formation and ultimately a heart attack. Until now it was believed that only oxidized low-density lipoprotein (LDL) triggered coronary artery disease. "Bacterial involvement in coronary artery disease has long been suspected, but direct and convincing evidence has been lacking," said Professor Pekka Karhunen, who led the study. "Our study demonstrated the presence of genetic material—DNA—from several oral bacteria inside atherosclerotic plaques."
Antibody breakthrough
Confirming the hypothesis
The study's findings were confirmed by developing an antibody against the identified bacteria. To the research team's surprise, this antibody revealed biofilm structures in arterial tissue. The researchers also found bacteria released from the biofilm in cases of myocardial infarction, confirming their initial hypothesis about the role of these bacterial biofilms in heart attacks.