Association between Periodontal Pathogens and Coronary Artery Disease: A Case-Control Study
Background: We sought to answer the questions about the role of inflammatory factors in the formation of pathological lesions in the endothelium of the coronary vessels and also the role of hostbased bacteria, including chronic periodontitis, in the clot formation in the blood vessels, all of which destabilize the atherosclerotic plaque.
Methods: This case-control study was done on 40 patients who underwent elective coronary artery bypass grafting surgery (CABG) with the need of coronary endarterectomy. In Group A, patients had chronic periodontitis and group B consisted of patients without it. Both groups were well matched regarding their demographic data. The subgingival plaque was collected by a sterile curette from periodontal pockets ≥ 5mm and CAL ≥ 4mm. Also, atherosclerotic plaque was collected during the coronary endarterectomy surgery from all of the 40 patients. The specimens were assessed using the PCR technique to detect the specific bacteria responsible for chronic periodontitis such as actinobacillus actinomycetemcomitans (Aa), prevotella intermedia (Pi), porphyromonas gingivalis (Pg), Tanerella forsythensis (Tf), Treponema denticola (Td), and fusobacterium nucleatum (Fn).
Results: In the atherosclerotic plaque of group A patients, Aa was identified in 18 (90%), Pg in 16 (80%), Tf in 13(65%),Td in 11 (55%), Pi in 10 (50%), and Fn in 6 (30%) specimens, whereas in group B the incidence was significantly lower (p< 0.0001). In the subgingival plaque of group A, Aa and Tf were found in all 20 individuals and Pg, Pi, Td and Fn were identified in 19 specimens (95%). The differences in the incidence of Aa and Pg in two plaque samples were not significant, but the two plaque samples showed significant differences regarding the incidence of the other pathogens ( Pi : p<0.001, Tf : p<0.008, Td: p<0.003 and Fn :p<0.0001).
Conclusions: In the present study, the same organisms were found in both coronary atherosclerotic and subgingival plaques. The findings support the potential role of the periodontopathogenic bacteria species in some steps of the atherosclerotic process as a contributor that worsens this disease. However, further studies are required to achieve more definite results regarding the role of periodontal diseases in the atherosclerotic disease, focusing on patients' background variables.