Detection of periodontal microorganisms in coronary atheromatous plaque specimens of myocardial infarction patients: A systematic review and meta-analysis.

BACKGROUND: Microbial translocation from inflamed periodontal pockets into coronary atheroma via systemic circulation is one of the proposed pathways that links periodontitis and myocardial infarction (MI). The purpose of this systematic review is to determine the reported prevalence of periodontal microorganisms in coronary atheroma and/or aspirated clot samples collected from MI patients with periodontal disease. METHODOLOGY: The "Preferred Reporting Items for Systematic Reviews and Meta-Analyses" (PRISMA) guidelines were followed. Six databases were systematically searched using Medical Subject Headings/Index and Entree terms. After a thorough screening, fourteen publications spanning over ten years (2007-2017) were eligible for this systematic review and meta-analysis. RESULTS: Out of 14 included studies, 12 reported presence of periodontal bacterial DNA in coronary atherosclerotic plaque specimens. Overall, Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans were the most frequently detected periodontal bacterial species. Meta-analysis revealed that the prevalence of P. gingivalis was significantly higher than A. actinomycetemcomitans in coronary atheromatous plaque samples. Apart from periodontal microbes, DNA from a variety of other microbes e.g. Pseudomonas fluorescens, Streptococcus species, Chlamydia pneumoniae were also recovered from the collected samples. CONCLUSION: Consistent detection of periodontal bacterial DNA in coronary atheroma suggests their systemic dissemination from periodontal sites. It should further be investigated whether they are merely bystanders or induce any structural changes within coronary arterial walls.

Bacterial footprints in aspirate of infarct-related artery in ST-elevation myocardial infarction patients underwent primary percutaneous coronary intervention.

BACKGROUND: Bacterial infections can trigger acute coronary syndromes. This study aimed to examine bacterial footprints in the aspirate of infarct-related artery. PATIENTS AND METHODS: We studied 140 patients with ST-elevation myocardial infarction who underwent a primary coronary intervention using thrombus aspiration catheters. The aspirate was sent for bacteriological and pathological examinations and immunoassay for pneumolysin toxin. RESULTS: Bacterial culture showed different bacteria in 14 samples. Leukocyte infiltrate was detected in all pathologically examined samples. Pneumolysin toxin was detected in only two samples. Patients with bacteria had similar baseline data as those without, except for the median age [46 (44-50) vs. 55 (47-62) years, P = 0.001, respectively], and white blood cells (WBCs) (16670 vs. 7550 cells/µl, P < 0.0001, respectively). In hospital-major clinical events (death, stroke, reinfarction, lethal arrhythmia, and heart failure) were not significantly different between the 2 groups with and without bacteria [4 (28.6%) vs. 20 (18.6%) events, respectively, odds ratio (OR) 1.8 (95% CL: 06-6.3), P = 0.5]. Patients with bacteria, heavy infiltration, and pneumolysin had insignificant higher events compared with those without [10/35 (28.6%) vs. 16/105 (15.2%) events, OR 2.2 (95% CL: 0.92-5.43), P = 0.13]. However, the difference was not significant. By multivariate analysis, bacteria, leukocyte infiltration, and pneumolysin were not predictors for in-hospital clinical events. Higher WBCs and younger age were significant predictors of bacterial footprints (P < 0.0001 and P = 0.04, respectively). CONCLUSION: Bacterial footprints existed in the aspirate of infarct-related artery of ST-elevation myocardial infarction patients. Predictors were higher WBCs and younger age. Bacterial markers were not predictors for in-hospital clinical events. The presence of bacterial footprints supports the infectious hypothesis of atherosclerosis.

An unusual case of mycobacterium tuberculous coronary arteritis and thrombosis resulting in acute myocardial infarction.

Tuberculosis (TB) is a prevalent infection worldwide and an endemic infection in Singapore. The most common presentation is that of pulmonary tuberculosis. Extra pulmonary tuberculosis usually involves the lymph nodes, pleura, central nervous system, or abdominal cavity. Involvement of the heart is rare (0.14-2% of TB cases), and when it is involved, it tends to be in the pericardium or myocardium. Here, a rare case of sudden death due to tuberculous coronary arteritis with tuberculous coronary thrombosis resulting in acute myocardial infarction is presented.

Pseudomonas aeruginosa Microcolonies in Coronary Thrombi from Patients with ST-Segment Elevation Myocardial Infarction.

Chronic infection is associated with an increased risk of atherothrombotic disease and direct bacterial infection of arteries has been suggested to contribute to the development of unstable atherosclerotic plaques. In this study, we examined coronary thrombi obtained in vivo from patients with ST-segment elevation myocardial infarction (STEMI) for the presence of bacterial DNA and bacteria. Aspirated coronary thrombi from 22 patients with STEMI were collected during primary percutaneous coronary intervention and arterial blood control samples were drawn from radial or femoral artery sheaths. Analyses were performed using 16S polymerase chain reaction and with next-generation sequencing to determine bacterial taxonomic classification. In selected thrombi with the highest relative abundance of Pseudomonas aeruginosa DNA, peptide nucleic acid fluorescence in situ hybridization (PNA-FISH) with universal and species specific probes was performed to visualize bacteria within thrombi. From the taxonomic analysis we identified a total of 55 different bacterial species. DNA from Pseudomonas aeruginosa represented the only species that was significantly associated with either thrombi or blood and was >30 times more abundant in thrombi than in arterial blood (p<0.0001). Whole and intact bacteria present as biofilm microcolonies were detected in selected thrombi using universal and P. aeruginosa-specific PNA-FISH probes. P. aeruginosa and vascular biofilm infection in culprit lesions may play a role in STEMI, but causal relationships remain to be determined.

Coronary artery embolism from infectious endocarditis treated with catheter thrombectomy using a GuideLiner catheter.

A 27-year-old male with history of IV drug use and recurrent endocarditis necessitating bioprosthetic mitral and tricuspid valve replacements presented with 2 weeks of fevers and chest pain. ECG revealed inferior ST-elevation myocardial infarction and he was taken urgently to the cardiac catheterization laboratory. Coronary angiography revealed thrombotic occlusion of the distal right coronary artery (RCA) with no angiographic evidence of atherosclerotic disease. Aspiration thrombectomy was performed followed by rheolytic thrombectomy. Despite multiple attempts at thrombectomy, significant residual organized thrombus persisted in the distal RCA. Therefore, further thrombectomy was performed by placing a GuideLiner catheter (Vascular Solutions, Minneapolis, MN) deep within the right coronary artery near the bifurcation into the posterior descending and posterior left ventricular arteries. After repeat aspiration, there was significant improvement with thrombolysis in myocardial infarction 3 flow. Intravascular ultrasound of the RCA revealed a normal-appearing vessel without evidence of atherosclerotic disease and mild residual thrombus. The decision was made to not pursue stent placement, given the concern for a likely embolic source. Following the procedure, the patient's chest pain resolved and his ST-segments normalized.

Coronary neutrophil extracellular trap burden and deoxyribonuclease activity in ST-elevation acute coronary syndrome are predictors of ST-segment resolution and infarct size.

RATIONALE: Mechanisms of coronary occlusion in ST-elevation acute coronary syndrome are poorly understood. We have previously reported that neutrophil (polymorphonuclear cells [PMNs]) accumulation in culprit lesion site (CLS) thrombus is a predictor of cardiovascular outcomes. OBJECTIVE: The goal of this study was to characterize PMN activation at the CLS. We examined the relationships between CLS neutrophil extracellular traps (NETs), bacterial components as triggers of NETosis, activity of endogenous deoxyribonuclease, ST-segment resolution, and infarct size. METHODS AND RESULTS: We analyzed coronary thrombectomies from 111 patients with ST-elevation acute coronary syndrome undergoing primary percutaneous coronary intervention. Thrombi were characterized by immunostaining, flow cytometry, bacterial profiling, and immunometric and enzymatic assays. Compared with femoral PMNs, CLS PMNs were highly activated and formed aggregates with platelets. Nucleosomes, double-stranded DNA, neutrophil elastase, myeloperoxidase, and myeloid-related protein 8/14 were increased in CLS plasma, and NETs contributed to the scaffolds of particulate coronary thrombi. Copy numbers of Streptococcus species correlated positively with dsDNA. Thrombus NET burden correlated positively with infarct size and negatively with ST-segment resolution, whereas CLS deoxyribonuclease activity correlated negatively with infarct size and positively with ST-segment resolution. Recombinant deoxyribonuclease accelerated the lysis of coronary thrombi ex vivo. CONCLUSIONS: PMNs are highly activated in ST-elevation acute coronary syndrome and undergo NETosis at the CLS. Coronary NET burden and deoxyribonuclease activity are predictors of ST-segment resolution and myocardial infarct size.

Detection of periodontal bacteria in thrombi of patients with acute myocardial infarction by polymerase chain reaction.

BACKGROUNDS: Numerous reports have demonstrated that periodontal bacteria are present in plaques from atherosclerotic arteries. Although periodontitis has recently been recognized as a risk factor for coronary artery disease, the direct relationship between periodontal bacteria and coronary artery disease has not yet been clarified. It has been suggested that these bacteria might contribute to inflammation and plaque instability. We assumed that if periodontal bacteria induce inflammation of plaque, the bacteria would be released into the bloodstream when vulnerable plaque ruptures. To determine whether periodontal bacteria are present in thrombi at the site of acute myocardial infarction, we tried to detect periodontal bacteria in thrombi of patients with acute myocardial infarction by polymerase chain reaction (PCR). METHODS: We studied 81 consecutive adults with ST-segment elevation acute myocardial infarction who underwent primary percutaneous coronary intervention (PCI). All patients underwent removal of thrombus with aspiration catheters at the beginning of percutaneous coronary intervention, and a small sample of thrombus was obtained for PCR. RESULTS: The detection rates of periodontal bacteria by PCR were 19.7% for Aggregatibacter actinomycetemcomitans, 3.4% for Porphyromonas gingivalis, and 2.3% for Treponema denticola. CONCLUSIONS: Three species of periodontal bacteria were detected in the thrombi of patients with acute myocardial infarction. This raises the possibility that such bacteria are latently present in plaque and also suggests that these bacteria might have a role in plaque inflammation and instability.

Coxiella burnetii infection of left atrial thrombus mimicking an atrial myxoma.

Infection of intracardiac thrombi is extremely unusual. Coxiella burnetii is a well-recognized etiologic agent of negative-blood culture endocarditis and vascular graft infection. Herein we describe the first reported case, to our knowledge, of C. burnetii infection of a large left-sided intracardiac thrombus that was initially misdiagnosed as an atrial myxoma. Diagnosis was confirmed by direct immunofluorescence assay, electron microscopy, and C. burnetii-specific polymerase chain reaction analysis performed on tissue sections of the thrombus.

Septic coronary embolism in aortic valvular endocarditis.

Acute myocardial infarction due to septic coronary emboli in active infective endocarditis is rare, but may be fatal. The case is reported of a 58-year-old man who presented with wrist arthritis, which resulted in acute aortic valvular endocarditis. Echocardiography revealed 3 mm vegetations on the posterior and anterior valve cusps, and aortic regurgitation (grade 3-4). As the patient's clinical status was stable, medical treatment was selected which included antibiotic therapy, but after four weeks the patient reported an acute anterior chest pain. Coronary angiography revealed stenosis of the left anterior descending (LAD) artery, due to septic embolism. The patient was referred for emergency cardiac surgery, at which a surgical thrombectomy and coronary artery bypass grafting with reconstruction of the LAD artery were performed, along with aortic valve replacement using a bioprosthesis. The postoperative course was uneventful and the patient was discharged on postoperative day 15. An adapted oral antibiotherapy was continued for a further six-week period.

Acute myocardial infarction caused by a septic coronary embolism diagnosed and treated with a thrombectomy catheter.

Acute myocardial infarctions are common in bacteraemia but are seldom diagnosed during life. A 64 year old man with severe chest pain who had fever for several days due to possible bacteraemia was shown by ECG and echocardiography to have possible lateral infarction. Immediate coronary angiography showed possible thrombus in the left circumflex artery, which was treated by thrombectomy catheter. Bacterial thrombus was removed and was verified by histological examination. A stent was implanted without complications. Acute myocardial infarction caused by septic embolism is usually fatal; however, thrombectomy may be useful in these cases.

Prolonged low-dose thrombolytic therapy: a novel adjunctive strategy in the management of an infected right atrial thrombus.

An 81-year-old man presented with a large, infected right atrial thrombus that was refractory to anticoagulants and several courses of antibiotics. The risk of surgical removal of the thrombus, which was associated with a pacemaker electrode, was considered prohibitive. The patient was treated for 7 days with low-dose (40 mg/day) tissue-type plasminogen activator (t-PA). Hemostatic monitoring during infusion revealed (1) a plasma t-PA antigen that was approximately 5% of that achieved during short-course t-PA for acute myocardial infarction, (2) biochemical evidence of prolonged clot lysis, and (3) no significant depletion of fibrinogen or plasminogen. Nearly complete dissolution of the thrombus was observed. His bacteremia was eradicated by intravenous penicillin despite the presence of the pacemaker lead. This case highlights the benefits of combined antibiotic and thrombolytic therapy and documents for the first time the response of the human hemostatic system to prolonged t-PA infusion and the plasma t-PA levels attained when thrombolytic therapy is administered in this manner. Prolonged courses of fibrinolytic agents may be a good alternative to surgical intervention in selected patients with infected, right-sided intracardiac thrombi.

Detection of Mycoplasma pneumoniae and Chlamydia pneumoniae in ruptured atherosclerotic plaques

This paper reports what is apparently the first observation of Mycoplasma pneumoniae in association with Chlamydia pneumoniae in thrombosed ruptured atheromas. We performed electron microscopy and in situ hybridization in specimens from three patients who died of acute myocardial infarction. These patients had typical symptoms of acute ischemic syndrome. Mycoplasmas were present mainly in the lipid core of the ruptured thrombosed plaque. Vulnerable atheromas are rich in cholesterol and may favor the growth of mycoplasmas, the only microorganisms that require cholesterol for survival. We suggest that the association of Mycoplasma pneumoniae and Chlamydia pneumoniae may increase the virulence of these microorganisms, favoring proliferation, plaque inflammation and possibly plaque rupture

Effects of oral flora on platelets: possible consequences in cardiovascular disease.

During episodes of dental bacteremia, viridans group streptococci encounter platelets. Among these microorganisms, certain Streptococcus sanguis induce human and rabbit platelets to aggregate in vitro. In experimental rabbits, circulating streptococci induced platelets to aggregate, triggering the accumulation of platelets and fibrin into the heart valve vegetations of endocarditis. At necropsy, affected rabbit hearts showed ischemic areas. We therefore hypothesized that circulating S. sanguis might cause coronary thrombosis and signs of myocardial infarction (MI). Signs of MI were monitored in rabbits after infusion with platelet-aggregating doses of 4 to 40 x 10(9) cells of S. sanguis 133-79. Infusion resulted in dose-dependent changes in electrocardiograms, blood pressure, heart rate, and cardiac contractility. These changes were consistent with the occurrence of MI. Platelets isolated from hyperlipidemic rabbits showed an accelerated in vitro aggregation response to strain 133-79. Cultured from immunosuppressed children with septic shock and signs of disseminated intravascular coagulation, more than 60% of isolates of viridans streptococci induced platelet aggregation when tested in vitro. The data are consistent with a thrombogenic role for S. sanguis in human disease, contributing to the development of the vegetative lesion in infective endocarditis and a thrombotic mechanism to explain the additional contributed risk of periodontitis to MI.

Candida albicans septic thrombosis of the right atrium is associated with a central venous catheter.

Right atrial thrombus formation is a rare complication of central venous catheterization in adults. Infection of this thrombus is exceptional. A case of a right atrial thrombus associated with Candida albicans infection is described. Surgical thrombectomy, withdrawal of the catheter, and long-term antiinfectious therapy seem the only appropriate treatment. The literature on this unusual condition is reviewed.