1 | Introduction
Cardiovascular diseases (CVDs) are the number one cause of death globally. In 2016, CVDs representing 31 % of all global deaths . According the 30th German national heart report published in 2018 coronary heart disease (CHD) with 7.9 % and acute myocardial infarction with 5.3 % were the leading causes of death in Germany. The treatment of patients with CHD is one of the most common medical tasks in developed industrial countries.
Coronary Artery Bypass Grafting (CABG) surgery is considered proven cardiac surgery standard procedure for patients with coronary multivessel disease and / or main coronary stenosis. CABG survival rates depend amongst other things on age. For instance in patients >70 years of age, 4-year adjusted survival rate for CABG was 95.0 %, in patients 70 to 79 years of age, survival rate was 87.3 %, and in patients ≥ 80 years of age, survival was 77.4 % . Other independent predictors for mortality after CABG were emergency operation, shock, preoperative renal failure, total bypass time, intraoperative stroke, postoperative myocardial infarction, gastrointestinal complications, respiratory failure .
Periodontitis is a chronic multifactorial host mediated inflammatory disease associated with dysbiotic plaque biofilms and characterized by progressive destruction of the tooth‐supporting apparatus . In a lot of cross-sectional and longitudinal studies a significant association was demonstrated between periodontitis and CVD [, independently of already known risk factors.
Many studies indicate a direct, biologically plausible relationship between periodontitis and CVD. The local host inflammatory response induced by periodontal pathogens promotes the passage of these microorganisms into the blood circulation . Such bacteremia and/or endotoxemia can be caused by invasive dental treatment such as scaling and root planing or even normal daily activities, like tooth brushing, flossing or food intake and is furthermore associated with the severity of periodontal disease . DNA of key bacteria for periodontitis have been found in both in atheromas and heart tissue . In another studyAggregatibacter actinomycetemcomitans was cultured from both, speciemens taken from periodontal pockets and atheromathous plaque at the same patient . This finding suggests that living bacteria can get from the oral cavity into the coronary arteries and may directly contribute to the pathogenesis of atherosclerosis. In animal experiments, another study showed that Porphyromonas gingivaliscan invade into heart tissue that has already been damaged by ischemia . This result could indicate that periodontal bacteria not only play a role in the development of atherosclerosis, but can also influence the cardiovascular outcome after a primary event.
Periodontitis and the associated increased bacterial load can also have an indirect proatherogenic and prothrombotic effect. Periodontitis was found associated to increased plasma lipid concentration, increased permeability of the coronary endothelium and increased binding of lipoproteins in the intima . Moreover, periodontitis is associated with an elevated general inflammatory status e.g. an increased level of C-reactive protein (CRP) promotes several proatherogenic and prothrombotic mechanisms such as endothelial dysfunction, monocyte–endothelial cell adhesion, accumulation of low-density lipoproteins (LDL) in macrophages, platelet aggregation, reactive oxygen species production, and decrease production of nitric oxide in endothelial cells .
Progression of CVD may be influence by successful periodontal treatment independent of traditional risk factors . Since periodontitis is an important factor in the pathogenesis of atherosclerosis, the aim of the present study was to investigate whether the periodontal status is associated with the postoperative course after CAGB surgery in patients with CHD. If such a relation would be found periodontal diagnosis and, if necessary, periodontal therapy early before CABG surgery may be indicated.