Brush and floss often to ward off heart attack

The Consorci Institut Catala de Ciencies Cardiovasculars (ICCC) in Spain was among the first to demonstrate an association between dormant invasive bacteria and degenerative tissue on artery walls. ICCC scientists also developed a method to isolate and cultivate bacterial pathogens from patient tissue for the first time.

The group recently completed work on an EU-funded study of patients undergoing surgery for arterial obstruction. The results of the project 'Discovery of atherosclerosis microbiome: Systems biology of cardiovascular pathogenesis' (CARDIOMICROBIOME) point to a different microbial environment in atherosclerotic tissue compared to that in healthy vascular tissue. This may partially explain why atherosclerosis does not always follow the patient profile associated with hypertension, hyperlipidaemia, diabetes and smoking.

In particular, using advanced molecular probes it was shown for the first time that within the same individual, there was a higher presence of bacterial species compared to a similar sample of healthy tissue. These bacteria are known to induce clotting of the blood. This points to a model where, unlike in the mouth, the bacteria in the arteries go relatively unnoticed for a long period of time, causing chronic low-grade inflammation. At some point, an as yet unclear trigger causes them to play a role in heart attack or stroke.

The data also support previous results from the same research group showing periodontal bacteria in the carotid arteries, the large arteries in the neck that carry blood from the heart to the brain. This provides a potential link between oral hygiene and brain-related diseases such as ischemic stroke and neurodegenerative conditions that requires further investigation.

CARDIOMICROBIOME results are important for a number of reasons. The link between oral hygiene and cardiovascular health provides a straightforward route to prevention of cardiovascular diseases through improved tooth and gum care. Identification of the bacteria present in the arterial plaques opens the door to use of antibiotics to treat atherosclerosis. Finally, demonstration of bacterial species from the mouth in the blood highlights the possibility of those bacteria setting up house virtually anywhere in the body.

The project has answered significant questions and, as all good research should, identified new ones and the direction of future studies. Practically, the potential benefits to health care costs and patient morbidity cannot be underestimated.