Isolated mitral valve endocarditis: Patient, disease, and surgical factors that influence outcomes.

OBJECTIVE: The objectives of this study were to investigate patient characteristics, valve pathology, bacteriology, and surgical techniques related to outcome of patients who underwent surgery for isolated native (NVE) or prosthetic (PVE) mitral valve endocarditis. METHODS: From January 2002 to January 2020, 447 isolated mitral endocarditis operations were performed, 326 for NVE and 121 for PVE. Multivariable analysis of time-related outcomes used random forest machine learning. RESULTS: Staphylococcus aureus was the most common causative organism. Of 326 patients with NVE, 88 (27%) underwent standard mitral valve repair, 43 (13%) extended repair, and 195 (60%) valve replacement. Compared with NVE with standard repair, patients who underwent all other operations were older, had more comorbidities, worse cardiac function, and more invasive disease. Hospital mortality was 3.8% (n = 17); 0 (0%) after standard valve repair, 3 (7.0%) after extended repair, 8 (4.1%) after NVE replacement, and 6 (5.0%) after PVE re-replacement. Survival at 1, 5, and 10 years was 91%, 75%, and 62% after any repair and 86%, 62%, and 44% after replacement, respectively. The most important risk factor for mortality was renal failure. Risk-adjusted outcomes, including survival, were similar in all groups. Unadjusted extended repair outcomes, particularly early, were similar or worse than replacement in terms of reinfection, reintervention, regurgitation, gradient, and survival. CONCLUSIONS: A patient- and pathology-tailored approach to surgery for isolated mitral valve endocarditis has low mortality and excellent results. Apparent superiority of standard valve repair is related to patient characteristics and pathology. Renal failure is the most powerful risk factor. In case of extensive destruction, extended repair shows no benefit over replacement.

Staphylococcus Aureus Infective Endocarditis: JACC Patient Pathways.

A 19-year-old female patient presented with Staphylococcus aureus infective endocarditis, with suspected subdural brain hemorrhage, disseminated intravascular coagulopathy, and septic renal as well as spleen infarcts. The patient had extensive vegetations on the mitral and tricuspid valves and underwent urgent mitral and tricuspid repair. This paper discusses the clinical case and current evidence regarding the management and treatment of Staphylococcus aureus endocarditis.

Modified commando procedure in complicated infective endocarditis ─ a case series.

BACKGROUND: Complicated infective endocarditis (IE) with perivalvular abscess and destruction of intervalvular fibrous body (IFB) has high mortality risk and requires emergent or urgent surgery mostly. CASE PRESENTATION: We presented four patients with complicated infective endocarditis combined with perivalvular abscess and IFB destruction. Three patients had prosthetic valve endocarditis and one patient had native valve endocarditis. They all received modified Commando procedure successfully. No surgical mortality or re-exploration for bleeding. CONCLUSIONS: We suggest that modified Commando procedure may have some benefit in improving survival rate of patients with complicated IE and reducing complications.

Basilar Artery Dissection Complicated with Infective Endocarditis.

A 14 year-old boy developed infective endocarditis of the mitral valve caused by Methicillin-sensitive Staphylococcus aureus and became comatose. Isolated basilar artery dissection was initially observed on the 3rd day by magnetic resonance imaging (MRI), ie, it did not exist on day 1. He underwent successful urgent mitral valve repair on the 5th day because of highly mobile vegetations and a newly emerged brain infarction under optimal antibiotic administration. Postoperatively, he recovered well and the basilar artery dissection was found to have recovered on an MRI on the 25th day without any specific intervention. This clinical course indicated that intracranial artery dissection may occur as a complication of infective endocarditis and supports the importance of the careful evaluation of brain MRI in patients with infective endocarditis.

Bacterial biofilms in infective endocarditis: an in vitro model to investigate emerging technologies of antimicrobial cardiovascular device coatings.

OBJECTIVE: In spite of the progress in antimicrobial and surgical therapy, infective endocarditis (IE) is still associated with a high morbidity and mortality. IE is characterized by bacterial biofilms of the endocardium, especially of the aortic and mitral valve leading to their destruction. About one quarter of patients with formal surgery indication cannot undergo surgery. This group of patients needs further options of therapy, but due to a lack of models for IE prospects of research are low. Therefore, the purpose of this project was to establish an in vitro model of infective endocarditis to allow growth of bacterial biofilms on porcine aortic valves, serving as baseline for further research. METHODS AND RESULTS: A pulsatile two-chamber circulation model was constructed that kept native porcine aortic valves under sterile, physiologic hemodynamic and temperature conditions. To create biofilms on porcine aortic valves the system was inoculated with Staphylococcus epidermidis PIA 8400. Aortic roots were incubated in the model for increasing periods of time (24 h and 40 h) and bacterial titration (1.5 × 104 CFU/mL and 1.5 × 105 CFU/mL) with 5 L cardiac output per minute. After incubation, tissue sections were analysed by fluorescence in situ hybridization (FISH) for direct visualization of the biofilms. Pilot tests for biofilm growth showed monospecies colonization consisting of cocci with time- and inocula-dependent increase after 24 h and 40 h (n = 4). In n = 3 experiments for 24 h, with the same inocula, FISH visualized biofilms with ribosome-containing, and thus metabolic active cocci, tissue infiltration and similar colonization pattern as observed by the FISH in human IE heart valves infected by S. epidermidis. CONCLUSION: These results demonstrate the establishment of a novel in vitro model for bacterial biofilm growth on porcine aortic roots mimicking IE. The model will allow to identify predilection sites of valves for bacterial adhesion and biofilm growth and it may serve as baseline for further research on IE therapy and prevention, e.g. the development of antimicrobial transcatheter approaches to IE.

[A 19-year-old woman with fever and high blood pressure]. / Eine 19-jährige Frau mit Fieber und Bluthochdruck.

A 19-year-old female patient was admitted to hospital for further diagnostics and treatment of a febrile infection. The cause was found to be a bronchopulmonary infection due to methicillin-sensitive Staphylococcus aureus (MSSA), which led to an infective endocarditis with mitral valve infestation and two splenic abscesses. Under treatment according to the antibiogram and laparoscopic excision of the splenic abscesses, the infection-related complications could be successfully resolved. Even during the physical examination there was a suspicion of Cushing's syndrome, which was confirmed by laboratory and radiological investigations and is associated with a general immune deficiency. Remarkable was that the initially difficult to adjust high blood pressure became normalized after transsphenoidal resection of the pituitary adenoma.

Bacterial colonization of explanted non-endocarditis cardiac valves: evidence and characterization of the valvular microbiome.

Bacterial colonization has been already demonstrated in heart valve tissues of patients without cardiovascular infections. However, the evidence of a valvular microbiome is still scarce. The next-generation sequencing method was carried out on 34 specimens of aortic (n = 20) and mitral valves (n = 14) explanted from 34 patients having neither evidence nor history of infectious diseases, particularly infective endocarditis. While no bacteria were demonstrated using standard culture methods, bacterial deoxyribonucleic acid (DNA) sequences were found using next-generation sequencing in 15/34 (44%) cases. Escherichia coli was present in 6 specimens and was the most frequently identified bacterium. There was a trend towards a higher rate of bacterial DNA positivity in specimens of calcific valves than in those of non-calcific valves (10/17 vs 5/17, P = 0.17). Based on a quantitative test, E. coli accounted for 0.7% ± 1% in calcific valvular tissue and 0.3% ± 0.3% in non-calcific valvular tissue (P = 0.2), and for 11% ± 27% in the valvular tissue of diabetic patients and 0.3% ± 1% in the valvular tissue of non-diabetic patients (P = 0.08). Detection of bacterial DNA in non-endocarditis valvular tissues could be a relatively common finding. There could be an association between the valvular microbiome and certain models of valve degeneration and common metabolic disorders.

[Clinical analysis of 14 infective endocarditis in patients with obstructive hypertrophic cardiomyopathy].

Objective: This observational study was aimed to analyze the clinical characteristics of infective endocarditis (IE) in patients with hypertrophic cardiomyopathy (HCM). Methods: A total of 668 patients with IE, and 7 427 patients with HCM were treated in Fuwai Hospital from August 2006 to December 2018. Among them, 14 patients were diagnosed with HCM and IE. The clinical characteristics of these patients including clinical manifestations, pathogen distribution, echocardiography features, in-hospital treatment and outcomes were analyzed retrospectively. Results: The proportion of HCM patients with IE was 0.19%,with the estimated incidence of 0.15/1 000 person-years in HCM patients. Of the 14 patients, 11 patients were male. The most common clinical manifestations were fever and heart murmur, and the main complications were heart failure (12/14) and bacterial embolism (8/14). There were 8 cases (8/14) with positive blood culture, and all causative bacteria were gram positive coccus, in which 5/8 were Streptococcus. The median interventricular septum thickness was (21.2±2.7) mm, and left ventricular outflow obstruction was severe based on echocardiography (Echo) examination. The Echo showed that vegetation was found in all 14 patients and most of the vegetation attached at the anterior leaflet of mitral valve (12/14). The proportions of patients with circulatory embolism (8/14) and valve lesions (12/14) were relatively high. Most cases (10/14) were cured, especially those underwent cardiac surgery (8 cases). The rest 4 cases died with 2 in hospital and 2 after auto-discharge. Conclusions: HCM patients complicated with IE are rare. Septic embolization and valve lesions are common in these patients. IE patients with HCM might have a poor prognosis compared to those without HCM and should receive cardiac surgery as early as possible.

Human disease caused by Streptococcus alactolyticus: a case report of native valve infective endocarditis and review of the literature.

Streptococcus alactolyticus, a member of the Streptococcus bovis/Streptoccus equinus complex, is primarily hosted in the gastrointestinal tract of animals and rarely of humans, with only scarce reports relating to human disease. We herein present a case of subacute infective endocarditis (IE) caused by S. alactolyticus in a 64-year old male with pre-existing mitral prolapse. Despite a 10-month history of low-grade fever and weight loss, the diagnosis of IE was triggered by left quadrant abdominal pain which revealed splenic infarcts on computed tomography. A definitive diagnosis of IE was subsequently established by four consecutive blood cultures positive for S.alactolyticus plus demonstration of a vegetation on the mitral valve by trans-esophageal ultrasound. Further workup revealed multiple embolic phenomena including brain and spine. A dental abscess was identified as the most probable origin of the bacteraemia, while colonoscopy revealed no evidence of cancer. The patient recovered uneventfully with antibiotic treatment and underwent successful cardiac surgery post-discharge. Although rare, IE caused by S. alactolyticus may be severe and of obscure origin; oral cavity should not be overlooked as a possible origin. Attention should be given in patients with preexisting risk factors.

Mitral Valve Endocarditis: A Rare Manifestation of Lyme Disease.

Valvular involvement in Lyme disease is rare. Confirmation of Borrelia species as the causative agent with polymerase chain reaction was done in a few cases in Europe and the United States. We describe a case of mitral regurgitation with a preoperative diagnosis of myxomatous mitral valve degeneration. During surgery, the surgeon suspected infective rather than degenerative etiology; the results of tissue cultures were negative. However, universal bacterial polymerase chain reaction on explanted valve tissue detected Borrelia burgdorferi DNA. If a surgeon suspects infective endocarditis at the time surgery, appropriate specimens should be sent for histopathologic analysis, culture, and polymerase chain reaction assay.

Efficacy of Glutaraldehyde-Treated Leaflets for Mitral Valve Repair to Treat Active Infective Endocarditis: A Case Report.

We report the use of glutaraldehyde (GA) in a case of valve repair for mitral valve prolapse associated with active infective endocarditis. GA scrubbed at the site of infection decontaminates and reinforces infected fragile tissue, avoids excessive debridement, and strengthens the edges of valve leaflets to facilitate suturing.

Difference in Outcome Following Surgery for Native Aortic and Mitral Valve Infective Endocarditis.

BACKGROUND: We investigated differences in clinical presentation, microbiology, and short- and long-term results according to the affected valve in patients who underwent surgery for left-sided native valve infective endocarditis (IE). METHODS: This was a single-center retrospective study of 117 patients with isolated mitral valve IE (group M) and 140 patients with isolated aortic valve IE (group A) who underwent surgery between 1998 and 2015. RESULTS: The mean age of patients in group M was 62 ± 14 years, whereas in group A the patients were 56 ± 14 years old (p = 0.001). There were 61 females (52% of patients) in group M and 31 females (22% of patients) in group A (p < 0.001). Abscesses were more common in group A than in group B. Staphylococcus aureus was more frequent in group M (47%, n = 55) than in group A (21%, n = 30; p < 0.001). The length of time from symptom onset to surgery was longer in group A than in group M, but the time from diagnosis to surgery was shorter in group A than in group M. Ninety-day mortality was similar in group M and group A in patients operated within 48 hours after diagnosis, but in patients who were operated more than 48 hours after diagnosis the 90-day mortality was 15% in group M and 3% in group A (p = 0.006). CONCLUSION: There were considerable differences in preoperative characteristics, microbiology, timing of surgery, and outcomes between patients who underwent surgery for isolated aortic valve IE and those who were operated for isolated mitral valve IE.

Surgery for Active Infective Endocarditis of the Aortic Valve With Infection Extending Beyond the Leaflets.

BACKGROUND: The optimal aortic substitute in extensive aortic valve active infective endocarditis (AIE) continues to be debated. To determine the surgical approach in aortic valve AIE with infection extension beyond the leaflets, we evaluated the outcome of reconstructive surgery with various valve substitutes in those patients. METHODS: During 2000-2013, 168 patients had surgery for extensive aortic valve AIE. Patients were categorised based on aortic valve substitute: Group A: Stented aortic valve replacement (AVR), Group B: Stented AVR with patch support, Group C: Stentless valve, Group D: Aortic allograft, and Group E: Composite valve graft. Outcome parameters were mortality, postoperative cardiogenic or septic shock, stroke, or reinfection. RESULTS: Stented valves with patch support were more frequently utilised in cases of native valve endocarditis (p<0.001). Postoperative complications were comparable among groups. Concomitant preoperative extension of infection in the mitral valve predicted reinfection (OR 3.6; confidence interval 1.46-8.66; p=0.005). Survival was not affected by operative group (log rank=0.6). Univariable preoperative predictors of mortality were: septic shock (hazard ratio 8.3; 95% confidence interval 3.6-19.2; p<0.001), ejection fraction (hazard ratio 0.96; 95% confidence interval 0.93-0.99; p=0.006), preoperative cardiogenic shock (hazard ratio 1.9; 95%CI 1.1-3.6, p=0.02) and concomitant mitral valve surgery (hazard ratio 1.8; 95% confidence interval 1.2-2.5; p=0.002). CONCLUSIONS: Surgical treatment of extensive aortic valve infective endocarditis remains a challenge. Outcomes were not affected by the surgical complexity of aortic reconstruction procedure or valve substitute. Surgical approach should be tailored to individual patient's characteristics.

Minimally Invasive Surgery in Mitral Valve Endocarditis.

BACKGROUND: To minimize the surgical damage, minimally invasive mitral valve surgery (MIMVS) has become the therapy of choice. However, this approach is technically more challenging, especially in endocarditis. The data on MIMVS in endocarditis are scarce, we therefore retrospectively analyzed the result at our institute. METHODS: From January 2011 and July 2017, 420 MIMVS were performed, out of which 44 (10%) were for endocarditis. Mean age was 55 ± 17 years and 41% (n = 18) were male. RESULTS: Euroscore II was 7.3 (range: 2-38). Operation times, cardiopulmonary bypass times, and clamp times were 230 (±77), 158 (±56), and 84 (±39) minutes, respectively. Seven cases (16%) were cardiac redo operations. Mitral valve repair and replacement was performed in 46 (n = 20) and 54% (n = 24) of patients, respectively. Overall in-hospital mortality, apoplexy, and reoperation rates (all for bleeding) were 7 (n = 3), 0 (n = 0), and 11% (n = 5), respectively. New onset of dialysis was required in three patients (7%). No patient developed superficial wound infection. Overall intensive care unit and hospital stay was 3 (±3) and 24 (±32) days, respectively. CONCLUSION: MIMVS can be performed with acceptable outcome and low perioperative morbidity in patients with mitral valve endocarditis. Especially absence of any postoperative wound infections and low rate of endocarditis recurrence; use of MIMVS must be encouraged as an eligible approach in most cases.

Safe Use of Glutaraldehyde to Repair the Destroyed Valve in Active Infective Mitral Valve Endocarditis.

BACKGROUND: The aim of this study was to review our experience of mitral valve (MV) repair for acute and active infective endocarditis (AAIE) and to identify the feasibility of a new approach together with the mid-term results. Methods and Results: A retrospective analysis was performed on 35 consecutive AAIE patients surgically treated in the isolated mitral position. Mean follow-up after the surgery was 4.3±3.7 years. 30 of the 35 patients were successfully treated by MV plasty (MVP); however, MV replacement (MVR) was necessary in the remaining 5 patients. Our novel approach included resection of the infective lesion, approximation with direct suture and/or patch repair with bovine or autopericardium after 2-min treatment of it and the defective leaflet edge(s) with 0.625% glutaraldehyde solution, reconstruction with artificial chordae and ring annuloplasty. The success rate of MVP was 85.7%. The longest postoperative follow-up echocardiography showed no mitral regurgitation (MR) in 4, trivial MR in 4, mild MR in 16 and moderate MR in 5 patients in the MVP group. The 5-year survival rate in the MVP group was 89±6%. MVR was required in 1 patient 2 months after MVP because of increasing MR. Recurrence of endocarditis has not been observed in any case. CONCLUSIONS: Glutaraldehyde was safely used in a surgical intervention for AAIE in the mitral position with acceptable early and mid-term results.