Metagenomic analysis of oral plaques and aortic valve tissues reveals oral bacteria associated with aortic stenosis.

OBJECTIVES: Bacteria derived from the oral cavity enter the bloodstream and cause the onset of various systemic diseases, including heart valve disease. However, information on the oral bacteria involved in aortic stenosis is limited. MATERIALS AND METHODS: We comprehensively analyzed the microbiota in aortic valve tissues collected from aortic stenosis patients using metagenomic sequencing and investigated the relationships between the valve microbiota, the oral microbiota, and oral cavity conditions. RESULTS: Metagenomic analysis revealed the presence of 629 bacterial species in five oral plaques and 15 aortic valve clinical specimens. Patients were classified into two groups (A and B) according to their aortic valve microbiota composition using principal coordinate analysis. Examination of the oral conditions of the patients showed no difference in the decayed/missing/filled teeth index. Bacteria in group B tend to be associated with severe disease, and the number of bacteria on the dorsum of the tongue and the positive rate of bleeding during probing were significantly higher in this group than in group A. The pathophysiology of aortic stenosis may be related to the presence of oral bacteria such as Streptococcus oralis and Streptococcus sanguinis following bacteremia. CONCLUSIONS: Systemic inflammation in severe periodontitis may be driven by the oral microbiota, supporting the indirect (inflammatory) association between oral bacteria and aortic stenosis. CLINICAL RELEVANCE: Appropriate oral hygiene management may contribute to the prevention and treatment of aortic stenosis.

Findings of prosthetic valve endocarditis in the balloon-expandable trans-catheter aortic valve: review of the literature and tips of management.

Prosthetic valve endocarditis after transcatheter aortic valve implantation (TAVI) is a rare complication associated with a high mortality rate. Nonetheless, the rapid expansion of TAVI in recent years has proportionally increased the number of patients exposed to the risk of developing transcatheter valve infection. A 71-year-old female with recent history of TAVI was diagnosed with prosthetic valve obstruction secondary to endocarditis. The characteristics of clinical presentation of endocarditis in the balloon-expandable transcatheter valve and the intra-operative findings are discussed with a review of the literature and tips of management.

Relationship of Streptococcus mutans with valvar cardiac tissue: A molecular and immunohistochemical study.

BACKGROUND: The present study aimed to investigate the presence or absence of Streptococcus mutans in oral cavity and valvular samples associating with the histomorphologic alterations of calcified aortic stenosis. METHODOLOGY: Dental plaque and cardiac valve samples were collected from 10 patients with calcified aortic stenosis for molecular analysis of S mutans by real-time polymerase chain reaction (PCR). Healthy valve tissue was also collected from five young cadavers and analyzed for S mutans. Moreover, fragments of all valvar specimens were submitted for histomorphological analysis and immunohistochemistry (anti-S mutans and anti-CD61). RESULTS: Streptococcus mutans was present in 100% of the oral cavity samples from the patients with calcified aortic stenosis in the molecular analysis. The analysis by real-time PCR showed that S mutans presented the same proportion in healthy valves and those with calcified aortic stenosis (80%; P = 1.000). Conversely, the immunoexpression of S mutans was 37.40 (IC95% = 1.49-937.00) times superior in samples of patients with cardiac disease (P = .007). The immunoexpression analysis showed that CD61 was present in seven (70%) calcified aortic stenosis samples, all of which were also immunopositive for S mutans. CONCLUSIONS: Streptococcus mutans was found in the oral cavity, healthy valve tissue, and calcified aortic stenosis samples. However, the microorganism was visualized by immunohistochemistry only in the calcified aortic stenosis samples, which may suggest viability and an increased bacterial density in this condition. The association of the presence of S mutans and positive CD61 immunoexpression suggests a probable relationship with calcified aortic stenosis.

Periodontal Bacterial DNA and Their Link to Human Cardiac Tissue: Findings of a Pilot Study.

BACKGROUND: The aim of this pilot study was to detect correlations of microbiological DNA, inflammatory proteins, and infection parameters in patients with periodontal disease (PD) and valvular heart disease (VHD). METHODS: A perioperative comprehensive dental examination for the investigation of periodontal status, including sampling of specific subgingival bacteria, was performed in 10 patients with indication for surgery of aortic valve stenosis with or without concomitant myocardial revascularization. Standard protocol biopsies were taken from right atrium (A), left septal myocardium (M), and aortic valve (V). Eleven periodontal pathogens DNA in oral and cardiac tissue samples (A/M/V) were analyzed using polymerase chain reaction. For cardiac tissue samples, Western blot analysis of LPS-binding protein (LBP), immunohistochemical (IHC) detection of LBP-big42, LPS-binding protein receptor (CD14), and macrophages (CD68), as well as inflammation scoring measurement were performed. RESULTS: Periodontitis was present in all patients with severe intensity in 7, moderate in 2 and mild in one patient. Same bacterial DNA was detected in A, M, and V in different distribution, and detection was more often in atrium than in myocardium or valve tissue. Morphological investigation revealed increased extracellular inflammatory cell migration. In IHC markers of LBP, CD68 and CD14 showed positive findings for all patients in atrium and myocardium. CONCLUSION: Our results demonstrate the presence of oral bacterial DNA in human cardiac tissue, as well as inflammatory markers potentially indicating connection of PD and VHD. Further investigation is necessary to confirm these preliminary data.

Bacterial translocation and plasma cytokines during transcatheter and open-heart aortic valve implantation.

OBJECTIVE: To determine whether the good safety profile of transarterial aortic valve implantation (TAVI) is related to lower levels of systemic bacterial translocation and systemic inflammation compared with open-heart surgery. BACKGROUND: Transcatheter aortic valve implantation via the transfemoral approach is increasingly used in very high-risk patients with aortic stenosis. The outcomes seem similar to those after open-heart aortic valve replacement (OHAVR). METHODS: Each of 26 consecutive high-risk patients (EuroSCORE >20% for risk of operative death) who underwent TAVI (cases) was matched to the first low-risk patient treated next in our department using elective OHAVR without coronary artery bypass (control subjects). We collected severity, outcome, and echocardiography indicators before and after surgery; complications; proinflammatory cytokine levels; and markers for microbial translocation. RESULTS: Despite greater illness severity, the TAVI patients had significantly lower vasopressor agent requirements, lower delirium rates, shorter hospital stays, and better hemodynamic findings compared with OHAVR patients. Vascular complications were more common after TAVI than after OHAVR (12, with seven requiring interventional therapy vs. 0, P = 0.006). Patients who underwent TAVI had lower blood transfusion requirements. Two TAVI patients died: one from iliac artery injury and the other from intracardiac prosthesis migration. Patients who underwent TAVI had lower plasma levels of endotoxin and bacterial peptidoglycan, as well as lower proinflammatory cytokine levels, suggesting less gastrointestinal bacterial translocation compared with OHAVR. CONCLUSIONS: Compared with OHAVR, TAVI was associated with decreases in bacterial translocation and inflammation. These differences may explain the lower delirium rate and better hemodynamic stability observed, despite the greater disease severity in TAVI patients.

Gemella morbillorum prosthetic aortic valve endocarditis.

Gemella morbillorum is facultative anaerobic, Gram-positive cocci and are a commensal part of human flora. The reported patient in this case, with a prosthetic bovine aortic valve, presented with fever, poor dental hygiene, new cardiac murmur and signs of congestive heart failure. Blood cultures were positive for a viridans streptococcal species; however, the organism could not be further identified at our institution. Echocardiogram demonstrated a decrease in ejection fraction and vegetation attached to the prosthetic aortic valve associated with a perivalvular abscess. The patient was treated with a 6-week regimen of penicillin G with gentamicin for the first 2 weeks along with cardiac surgery. The results from the 16S rRNA gene sequencing of the viridans streptococcal species were available, which reported the organism as G. morbillorum. This case adds to the literature on G. morbillorum prosthetic valve endocarditis and provides additional evidence to consider infectious endocarditis in the setting of G. morbillorum bacteraemia.

Aortic valve replacement and concomitant coronary artery bypass grafting in a patient with infective endocarditis and anomalous origin of the right coronary artery from the opposite sinus of valsalva.

A 69-yrs-old woman with anomalous origin of the right coronary artery from the opposite sinus of Valsalva (ACAOS) was diagnosed as having infective endocarditis affecting the aortic valve. Transthoracic echocardiography showed severe aortic stenosis and vegetations on the cusp of the aortic valve, which necessitated aortic valve replacement. Before the operation, computed tomography showed a right-ACAOS, with the artery running an interarterial course between the aorta and pulmonary artery. ACAOS running an interarterial course has been reported to be associated with an increased risk of ischemic cardiac events and sudden death. The patient was treated successfully by the aortic valve replacement with concurrent coronary artery bypass grafting using a saphenous vein graft for the right coronary artery.

One-year observation of inflammatory markers in patients with aortic valve stenosis who expressed high or low Chlamydia pneumoniae antibody titers.

BACKGROUND AND AIM OF THE STUDY: Aortic valve stenosis (AVS) and atherosclerosis can be regarded as two manifestations of the same pathological process. The study aim was to evaluate annually the plasma levels of C-reactive protein (CRP), interleukin-6 (IL-6) and tumor necrosis factor alpha (TNFalpha) in AVS patients, and to compare these data in AVS patients with and without high IgG, IgM, and IgA titers against Chlamydia pneumoniae. METHODS: Sixty patients with AVS who had declined the offer of remedial surgery were allocated to groups according to their antibody titers: group A (n=30, high IgG titer), group B (n=30, low IgG titer), group C (n=22, high IgA titer), group D (n=38, low IgA titer), group E (n=7, high IgM titer), and group F (n=53, low IgM titer) Antibody titers, serum levels of inflammatory markers and echocardiographic scans were monitored at 12-month intervals. RESULTS: During a one-year observation period, a greater number of patients in group A showed AVS deterioration compared to group B (p < 0.02). The mean IgA and IgM titers in group A were higher than in group B, while mean serum CRP and IL-6 levels, and IgG titer, tended to be higher in group C compared to group D. No statistically significant differences were identified in mean serum levels of CRP, IL-6, and TNFalpha between groups A and B. CONCLUSION: The results of the study suggested a possible association between C. pneumoniae infection and the progression of AVS.

Left main compression by an aortic root abscess.

A 79-year-old man with severe aortic stenosis, history of coronary artery disease and a recent hospitalization for sepsis presented at our institution following a syncope and angina at rest. Coronary angiography and aortography showed an aortic root abscess, causing left main coronary artery compression. This life-threatening complication of aortic valve endocarditis is rare and requires immediate surgical correction.

Demonstration of Chlamydophila pneumoniae, Mycoplasma pneumoniae, Cytomegalovirus, and Epstein-Barr virus in atherosclerotic coronary arteries, nonrheumatic calcific aortic and rheumatic stenotic mitral valves by polymerase chain reaction.

OBJECTIVE: The aim of this study was to investigate whether bacterial and viral infectious agents can be demonstrated in atherosclerotic lesions of patients with coronary artery disease (CAD) as well as in stenotic aortic and mitral valves from patients undergoing heart valve replacement. METHODS: In this cross-sectional study, the presence of Chlamydophila pneumoniae, Mycoplasma pneumoniae, Cytomegalovirus (CMV), and Epstein-Barr virus (EBV) was investigated by polymerase chain reaction in atherosclerotic and non-atherosclerotic vascular samples taken from patients undergoing coronary artery bypass surgery due to CAD, and from patients undergoing aortic (AVR) and/or mitral valve replacement (MVR) secondary to valvular stenosis. For statistical analyses ANOVA, Chi-square test or Fisher's exact test were used. RESULTS: The presence of C. pneumoniae, M. pneumoniae, and CMV in atherosclerotic versus non-atherosclerotic samples was as follows: 30% vs. 16.7% (p=0.222), 6.7% vs. 3.3% (p=0.554), and 10% vs. 0% (p=0.076), respectively. In valve group, same pathogens were present in AVR and MVR patients as follows: 24.2% vs. 21.4% (p=0.773), 9.1% vs. 7.1% (p=0.758), and 21.2% vs. 11.9% (p=0.275). EBV DNA was not detected in any of vascular specimens, but in one (3%) patient with AVR (p=0.256). CONCLUSION: Our results suggest that C. pneumoniae, M. pneumoniae, and CMV are present with similar frequency both in atherosclerotic and non-atherosclerotic vessels. We conclude that although non-atherosclerotic, vascular samples of CAD patients are invaded by infectious agents as like as atherosclerotic vessels. We further conclude that C. pneumoniae, M. pneumoniae, and CMV are present in stenotic aortic and mitral valves and atherosclerotic tissues with similar frequency indicating that atherosclerosis and valvular stenosis might share a common etiology related to infection.

Examination of periodontal pathogens in stenotic valve specimens and in whole blood samples in patients affected by aortic valve stenosis and chronic periodontitis.

Periodontitis may be a risk factor for atherosclerosis and coronary heart disease. The influence of periodontal pathogens in cardiovascular diseases needs further investigation. Therefore, the aims of this clinical study are: to test the presence of periodontal bacteria DNA in aortic valves and to assess the concomitant presence of the same periodontal bacteria DNA in whole blood samples in patients affected by aortic valve stenosis and chronic periodontitis. Nineteen consecutive patients (12 males and 7 females, age: 49-85 years) were enrolled in this study after having been subjected to a complete periodontal evaluation to confirm the diagnosis of chronic periodontitis. All patients were scheduled for aortic valve replacement surgery. After clinical and microbial periodontal examination, the aortic valve tissue specimens were obtained by excision during valve replacement surgery and the patients were subjected to the whole blood sampling before the surgery. The polymerase chain reaction technology was used to detect the putative periodontal pathogens Tannerella forshytia, Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Prevotella intermedia, Fusobacterium nucleatum, Campylobacter rectus, Eikenella corrodens and Treponema denticola. Neither the 19 aortic valve specimens nor the blood samples were positive for the genoma of the selected periodontal pathogens. The selected periodontal pathogens did not colonize the aortic valve of patients affected by stenosis and bacterial genoma was not present in whole blood samples. A high blood pressure at the aortic valve may prevent the adhesion and proliferation of bacterial colonies.

Presence of Chlamydophila pneumoniae DNA but not mRNA in stenotic aortic heart valves.

BACKGROUND: The pathogenesis of aortic valve stenosis may involve inflammation and we have previously demonstrated Chlamydophila pneumoniae (C. pneumoniae) DNA in stenotic aortic heart valves. Dissemination of these bacteria is probably mediated by alveolar macrophages. Bacterial DNA alone does not indicate whether the bacteria are viable and replicating. This study aimed to investigate the presence of C. pneumoniae mRNA, a marker of replicating bacteria, and C. pneumoniae DNA in stenotic aortic valves and the prevalence of C. pneumoniae in peripheral blood mononuclear cells (PBMC). METHODS: DNA was extracted from heart valves and PBMC and mRNA from heart valves from 76 patients undergoing aortic valve replacement surgery. C. pneumoniae DNA and mRNA were measured by real-time PCR targeting the ompA gene. RESULTS: C. pneumoniae DNA was demonstrated in 22% of heart valves and in 5% of PBMC. C. pneumoniae mRNA was not detected in any valve. Patients positive for C. pneumoniae in the valve underwent coronary artery by-pass grafting more often (p=0.01) and suffered from angina pectoris (p=0.02) and arterial hypertension (p=0.03) more often than patients negative for C. pneumoniae in the valve. CONCLUSIONS: These findings support a role for C. pneumoniae in the pathogenesis of aortic valve stenosis and indicate that the bacteria disseminate from the respiratory tract long before the patients were in need of surgery and that the valve infection thereafter entered into a persistent and non-replicative state. Moreover, patients positive for C. pneumoniae in the valve more often needed by-pass grafting because of more advanced coronary disease.

Pathogen burden in degenerative aortic valves is associated with inflammatory and immune reactions.

BACKGROUND AND AIM OF THE STUDY: The presence of five pathogens was assessed, together with a possible correlation of the total pathogen burden on inflammation and (auto)immunity in aortic stenosis (AS) and degenerative aortic valve bioprosthesis (BP). METHODS: Diseased valve specimens from a total of 68 patients (52 with AS, 16 with BP) were studied. The presence and localization was assessed of Chlamydia pneumoniae (cHSP60), Helicobacter pylori (HP), cytomegalovirus (CMV), Epstein-Barr virus (EBV) and herpes simplex virus (HSV), as well as of macrophages (CD68), C-reactive protein (CRP) and human heat shock protein 60 (hHSP60), by using immunohistochemical and morphometric analyses. RESULTS: In the majority of degenerative aortic valves, specific pathogens, inflammation and immunity were localized predominantly in the fibrosa of AS patients, and in superficial regions of the BP. The categorization of valves as having four or more pathogens (n = 37) or fewer pathogens (n = 31) demonstrated an increased signaling of CD68 (p = 0.03) and CRP (p = 0.02). Specifically, cHSP60, HP and hHSP60 levels were increased in valves where one or two bacteria were identified (n = 59) compared to those without bacterial presence (n = 9) (p = 0.04). CONCLUSION: The pathogen burden may contribute to valvular degeneration by promoting further deleterious inflammatory and (auto)immune processes at the level of the valvular fibrosa.

"When Aneurysm Ain't Aneurysm": sinus of Valsalva aneurysm mimicked by healed abscess cavity under the aortic valve.

In a 70-year-old patient with severe aortic valve stenosis, preoperative standard imaging (transthoracic echocardiography and angiography) detected an unclear subannular cavity structure. Initially interpreted as an aneurysm of Valsalva, the structure was identified intraoperatively as a huge chronic abscess cavity and exclusion was carried out by pericardial patch plasty. This case draws attention to the importance of a differential diagnosis of an abscess due to infective endocarditis in cases of unclear subannular structures rashly diagnosed as aneurysm of Valsalva.

Impact of bicuspid aortic valve on complications and death in infective endocarditis of native aortic valves.

We retrospectively investigated the impact of bicuspid aortic valve on the prognosis of patients who had definite infective endocarditis of the native aortic valve.Of 51 patients, a bicuspid aortic valve was present in 22 (43%); the other 29 had tricuspid aortic valves. On average, the patients who had bicuspid valves were younger than those who had tricuspid valves. Patients with a tricuspid valve had larger left atrial diameters and were more likely to have severe mitral regurgitation.Periannular complications, which we detected in 19 patients (37%), were much more common in the patients who had a bicuspid valve (64% vs 17%, P = 0.001). The presence of a bicuspid valve was the only significant independent predictor of periannular complications. The in-hospital mortality rate in the bicuspid group was lower than that in the tricuspid group; however, this figure did not reach statistical significance (9% vs 24%, P = 0.15). In multivariate analysis, left atrial diameter was the only independent predictor associated with an increased risk of death (hazard ratio, 2.19; 95% confidence interval, 1.1-4.5; P = 0.031).In our study, patients with infective endocarditis in a bicuspid aortic valve were younger and had a higher incidence of periannular complications. Although a worse prognosis has been reported previously, we found that infective endocarditis in a native bicuspid aortic valve is not likely to increase the risk of death in comparison with infective endocarditis in native tricuspid aortic valves.

Association between self-replicating calcifying nanoparticles and aortic stenosis: a possible link to valve calcification.

AIMS: Among various hypotheses proposed for pathological tissue calcification, recent evidence supports the possibility that self-replicating calcifying nanoparticles (CNPs) can contribute to such calcification. These CNPs have been detected and isolated from calcified human tissues, including blood vessels and kidney stones, and are referred to as nanobacteria. We evaluated calcific aortic valves for the presence of CNP. METHODS AND RESULTS: Calcific aortic valves were obtained from 75 patients undergoing surgical valve replacement. The control group was formed by eight aortic valves corresponding to patients with heart transplants. In the microbiology laboratory, valves were screened for CNP using a 4-6 weeks specific culture method. The culture for CNP was positive in 48 of the 75 valves with aortic stenosis (64.0%) in comparison with zero of eight (0%) for the control group (P = 0.0005). The observation of cultures by way of scanning electron microscopy highlighted the resemblance in size and morphology of CNP. CONCLUSION: Self-replicating calcific nanometer-scale particles, similar to those described as CNP from other calcific human tissues, can be cultured and visualized from calcific human aortic valves. This finding raises the question as to whether CNP contribute to the pathogenesis of the disease or whether they are only innocent bystanders.

Nanobacteria-associated calcific aortic valve stenosis.

Calcific aortic valve stenosis is the most common valvular disease in developed countries, and the major reason for operative valve replacement. In the US, the current annual cost of this surgery is approximately 1 billion dollars. Despite increasing morbidity and mortality, little is known of the cellular basis of the calcifications, which occur in high-perfusion zones of the heart. The case is presented of a patient with calcific aortic valve stenosis and colonies of progressively mineralized nanobacteria in the fibrocalcific nodules of the aortic cusps, as revealed by transmission electron microscopy. Consistent with their outstanding bioadhesivity, nanobacteria might serve as causative agents in the development of calcific aortic valve stenosis.