Native Aortic Valve Endocarditis Research Articles

Heparin-induced DRESS syndrome in a paediatric patient and successful anaesthetic management in cardiovascular bypass surgery: case report

BackgroundDrug Reaction with Eosinophilia and Systemic Symptoms (DRESS) Syndrome is a severe adverse drug reaction marked by delayed hypersensitivity reactions causing skin and systemic complications. DRESS diagnosis is challenging due to the variety of clinical presentations and symptom overlap with other conditions. The perioperative period in these patients requires precise pharmacological strategies to prevent complications associated with this syndrome. The treatment of DRESS induced by unfractionated heparin during cardiopulmonary bypass (CPB) surgery presents some challenges that must be considered when selecting an anticoagulant to avoid side effects. In this case, bivalirudin, a direct thrombin inhibitor, is indicated as an alternative to heparin in patients undergoing CPB. However, in contrast to heparin/protamine, there is no direct reversal agent for bivalirudin.Case presentationWe report the case of an 11-year-old male diagnosed with native aortic valve endocarditis and thrombosis in his left lower extremity. During valvular replacement surgery, systemic unfractionated heparin was administered. Postoperatively, the patient developed fever, eosinophilia and pruritic rash. Warm shock and elevated alanine transaminase (ALT) and aspartate transaminase (AST) levels followed, leading to the diagnosis of DRESS syndrome. Treatment with methylprednisolone resulted in complete resolution of symptoms. Seven years later, the patient was readmitted due to insufficient anticoagulation and a thrombus in the prosthetic aortic valve, presenting a recurrent DRESS episode due to the administration of unfractionated heparin, which was later replaced with low-molecular-weight heparin during hospitalization. Treatment with corticosteroids and antihistamines was initiated, resulting in the resolution of this episode. Ultimately, the patient required the Ross procedure. During this intervention the anticoagulation strategy was modified, unfractionated heparin was replaced with bivalirudin during the procedure and fondaparinux was administered during the postoperative period. This resulted in stable transaminases levels and no eosinophilia.ConclusionThe severity of DRESS Syndrome underscores the importance of early recognition, heightened monitoring, and a comprehensive approach tailored to each patient’s needs. This particular case highlights the significance of this approach and may have a substantial clinical impact since it provides alternatives to heparin, such as bivalirudin and fondaparinux, in the anticoagulation strategy of CPB for patients who have a hypersensibility reaction to this medication; thus, enhancing clinical outcomes by minimizing risks linked to adverse drug reactions.

Streptococcus canis native aortic valve endocarditis linked to cat exposure: A Case Report and Review

Streptococcus canis native aortic valve endocarditis linked to cat exposure: A Case Report and Review

Abstract 17883: Subacute Native Aortic and Mitral Valve Endocarditis Manifesting as Embolic ST-Elevation Myocardial Infarction

Case description: A 54-year-old male presented with one day of substernal chest pain. He also reported two months of malaise, myalgias, chills, and intermittent fevers. Medical history was notable for well-controlled hypertension and negative for dyslipidemia, diabetes, or drug and tobacco use. Family history was negative for premature coronary artery disease. Vitals were notable for fever of 103F, blood pressure of 108/56 mmHg, and heart rate of 88 beats per minute. Physical exam showed bounding pulses and a soft diastolic murmur at the left lower sternal border. Electrocardiogram showed inferior lead ST-elevations. He was taken for cardiac catheterization and found to have a totally occlusive thrombus in the distal right coronary artery with minimal disease in the remaining vessels. He underwent aspiration thrombectomy and placement of drug eluting stent with normal flow. He was transferred to the coronary intensive care unit. Labs showed mild leukocytosis, normal serum creatinine, and unremarkable urinalysis. Echocardiogram showed a 1.7 x 0.5 cm mobile echodensity on the aortic valve with severe aortic regurgitation and a small echodensity on the anterior mitral leaflet. Blood cultures grew Enterococcus faecalis. A CT scan of the head, chest, abdomen, and pelvis revealed no embolic disease. He underwent urgent surgery due to concern for infective endocarditis with coronary embolism. Purulence was found at the stent site and the posterior descending artery was obliterated by necrotic tissue. A bypass graft was placed distal to the stent site and infected territory was unroofed and irrigated. Mitral and aortic valve replacement was performed. He tolerated surgery and was discharged with 6 weeks of intravenous antibiotics. Discussion: This case was unique in the subacute chronicity of endocarditis and lack of other systemic emboli. Clinically relevant coronary embolism was reported in only 1.5% of cases of infective endocarditis but microemboli were found in 60% postmortem. Embolization is more common with mitral valve involvement, >10 mm vegetation, and fungal or staphylococcal disease. Angiographic evidence of heavy thrombus burden or lack of significant atherosclerosis after myocardial infarction may prompt evaluation for coronary embolism.

Neutrophilic Leukocytes and Neutrophil Extracellular Traps in Native Aortic Valve Endocarditis

Abstract Infective endocarditis is a disease that affects the endocardium and often alters heart valves, notably the aortic valve. Bacteraemia and valvular endothelial damage play an essential role in the pathogenesis of infective endocarditis. The pertinent literature suggests that neutrophil extracellular traps are important contributors to the development of the disease. However, features of the valvular damage and contribution of neutrophils to the alteration of cardiac tissue are not explored sufficiently. The purpose of this study was to investigate the occurrence and distribution of neutrophilic leukocytes and neutrophil extracellular traps in native aortic valves affected by infective endocarditis, using histopathology and immunohistochemistry assays. In addition, the presence of vegetations on the heart valve was determined. Infiltration of neutrophils into the valvular leaflet was significantly more severe at the free margin (mean 5.89 ± 3.00, p < 0.001) and the middle portion (mean 4.58 ± 3.64, p = 0.032) when compared to the base portion (2.05 ± 1.90). No significant differences in neutrophilic leukocyte infiltrating inflammatory lesions were found between cusp layers. The presence of myeloperoxidase and citrullinated histone expression characteristic of neutrophil extracellular traps was demonstrated by the use of immunohistochemistry in IE-affected valvular leaflets and vegetations. Collectively, the study results suggest that the free cusp margin and its middle portion of the aortic valve are exposed to enforced blood flow; endothelial damage and vegetation formation are likely to occur along with the presence of infective endocarditis-related bacteraemia.

Invasive Coronary Angiography in Patients with Native or Prosthetic Aortic Valve Endocarditis.

Invasive coronary angiography (ICA) is essential to detect significant coronary artery disease (CAD) but is generally not recommended in patients with infective aortic valve endocarditis. This study aimed to evaluate the risks and benefits of preoperative ICA in patients before aortic valve replacement. Between March 2008 and September 2020, 232 patients were surgically treated for infectious endocarditis of the aortic valve. Sixty-seven (29%) of them underwent preoperative diagnostic ICA and were compared with the patients without preoperative ICA. We collected their baseline characteristics, including the neurological status, previous cardiac surgical procedures, and reviewed the preoperative echocardiograms and the ICA data. The intraoperative data and clinical outcomes after ICA and after surgery were evaluated. ICA revealed a CAD in the majority of our patients (n = 36; 54%): One-vessel disease n = 19 (28%), two-vessel disease n = 6 (9%), and three-vessel disease n = 11 (16%). We observed no adverse events following preoperative diagnostic ICA, particularly no thromboembolic complications, including stroke, visceral, or lower body ischemia were detected. During surgical aortic valve replacement, concomitant coronary artery bypass grafting was performed in 20 patients (30%). In patients with preoperative ICA, postoperative in-hospital mortality was significantly lower (n = 8 [12%] vs. n = 30 [18%]; p < 0.001), while the incidence of postoperative bleeding was higher (n = 18 [27%] vs. n = 22 [13%]; p = 0.022). The new-onset stroke incidence was 5% in each group. Taking a multidisciplinary team approach, ICA is safe in selected patients with aortic valve infectious endocarditis with no adverse clinical outcomes, but significant clinical implications.

Evaluation of a rapid deployment prosthesis strategy for the treatment of aortic valve endocarditis.

The aim of this study was to evaluate the surgical outcome of patients suffering from native aortic valve (NVE) or prosthetic aortic valve endocarditis (PVE) treated with the EDWARDS INTUITY Elite rapid-deployment valve prosthesis. Between February 2019 and June 2020, 25 patients suffering from NVE (n = 9; 36%) and PVE (n = 16; 64%) of the aortic valve received an INTUITY valve at our institution. Preoperative, operative and follow-up data were collected. In our cohort, the mean EuroSCORE II was 13.4%. Eleven patients (44%) received concomitant aortic root patch plasty. Four patients (16%) received coronary artery bypass graft surgery, 3 patients (12%) received mitral valve repair and 2 patients (8%) underwent replacement of the ascending aorta. The cardiopulmonary bypass and aortic cross-clamp times were 124 ± 56 and 75 ± 39 min, respectively. The mean intensive care unit stay was 5 days. The mean size of the implanted prostheses was 25 ± 2 mm and the mean prosthesis transvalvular gradient 3 months after surgery was 9 ± 4 mmHg. During follow-up, no case of recurrent endocarditis occurred, 1 patient died of multisystem organ failure which had already been present preoperatively. Surgery for NVE and PVE of the aortic valve may be safely performed using the EDWARDS INTUITY Elite valve system. This procedure could be well implemented in cases with extensive infection, fragile root tissue and root abscesses requiring root reconstruction. In our institution, the rapid-deployment aortic valve replacement strategy has become an important tool in the armamentarium of the surgical endocarditis treatment.

Multiple systemic cardio-embolism in native aortic valve endocarditis

We present a challenging case of native aortic valve endocarditis with Enterococcus faecalis in a patient with a history of multiple urinary tract infections and urethral strictures treated by local dilations. The case was complicated by Clostridium difficile colitis and multiple septic embolization. Despite intensive antibacterial therapy, guided by the antibiogram, the vegetations grew in size and the infection became uncontrolled causing recurrent embolism.

Double valve infective endocarditis due to Capnocytophaga canimorsus

Infective endocarditis caused by Capnocytophaga canimorsus, a commensal organism commonly found in dog saliva, is uncommon. We describe a case of a 76-year-old male with native aortic and mitral valve endocarditis with ventricular-atrial fistulization due to Capnocytophaga canimorsus. He was successfully treated with intravenous antimicrobials and surgery. Capnocytophaga canimorsus should be considered as a cause of infective endocarditis in patients with negative blood cultures, in asplenic patients, and in those with appropriate exposures.

Coronary angiography in patients with native or prosthetic aortic-valve endocarditis: outcomes and implications for myocardial revascularisation

Abstract Background Coronary angiography (CA) remains the cornerstone of the preoperative assessments before open-heart surgery to detect or rule out coronary artery disease (CAD). Preoperative CA is currently not recommended in patients with active infective aortic valve endocarditis, but may help to reduce the risk of perioperative myocardial infarction. Purpose This study aimed to evaluate the risks and benefits of preoperative CA in selected patients before aortic valve replacement to treat active infective endocarditis of the aortic valve and to assess the incidence and relevance of CAD. Methods Sixty-five patients with native or prosthetic aortic-valve endocarditis underwent preoperative diagnostic CA between 03/2008 and 09/2020. We collected their baseline characteristics, including the neurological status, previous cardiac surgical procedures, and reviewed the preoperative echocardiograms and the CA data. We evaluated the intraoperative data, and clinical outcomes after CA and after surgery. Patients were selected according to the site, size and mobility of vegetations of the underlying active infective process. Results CA revealed CAD in the majority of patients (n=34; 52%): one-vessel disease n=17 (26%), two-vessel disease n=6 (9%), and three-vessel disease n=11 (17%). Coronary sclerosis without hemodynamic significance were detected in 23 patients (35%). Sixteen patients had a previous history of CAD. We observed no adverse events following preoperative diagnostic CA, particularly no thromboembolic complications, including stroke, visceral, or lower body ischaemia. Surgery was performed 3 [IQR 1; 5] days after CA. During surgical aortic-valve replacement, concomitant coronary artery bypass grafting was performed in 19 patients (29%). Postoperative in-hospital mortality was 12% (n=8) and the new-onset disabling-stroke incidence was 2% (n=1). Neither stroke nor visceral or lower body ischemia due to embolism were observed in any patient after surgery. Conclusions By weighing risks and benefits of CA together as a team, no adverse clinical outcomes but significant clinical implications could be identified in patients with active infective aortic valve endocarditis. Concomitant surgical myocardial revascularization was frequent and may well have contributed to favorable clinical outcome. Therefore, active infective endocarditis of the aortic valve per se should not be regarded as an absolute contraindication for CA. Funding Acknowledgement Type of funding sources: None.

Aortic valve endocarditis in patients with bicuspid and tricuspid aortic valves

ObjectiveTo determine the long-term survival and rate of reoperation after surgical treatment of infective endocarditis (IE) in patients with a bicuspid aortic valve (BAV) and patients with a tricuspid aortic valve (TAV). MethodsBetween 1997 and 2017, 210 patients underwent surgical treatment for native aortic valve endocarditis, including 51 patients with BAV (24%) and 159 patients with TAV (76%). Data were obtained from the Society of Thoracic Surgeons data warehouse and hospital medical record review, supplemented with surveys and national death index data for more complete follow-up. ResultsCompared with the TAV IE group, the BAV IE group was significantly younger (42 years vs 54 years) and had lower incidence rates of hypertension, coronary artery disease, and congestive heart failure (CHF). There were no significant between-group differences in postoperative stroke, sepsis, pacemaker requirement, or in-hospital mortality (2.0% vs 4.4%). Liver disease was a risk factor for operative mortality (odds ratio [OR], 13; 95% CI, 3.3-30; P = .0002). The 10-year survival rate was 64% for the BAV group versus 46% for the TAV group (P = .0191). Significant risk factors for long-term mortality were intravenous drug use (hazard ratio [HR], 4.5; P < .0001), preoperative renal failure requiring dialysis (HR, 4.13; P < .0001), CHF (HR, 1.7; P = .04), and liver disease (HR, 2.6; P = .02). The HR for BAV was 0.67 (95% confidence interval [CI], 0.3-1.4). The 10-year postoperative cumulative incidence of reoperation was significantly higher in the BAV patients compared with the TAV patients (5.7% vs 4.5%; P = .045) with an HR of 2.4 (95% CI, 0.8-7.1; P = .11) for BAV. ConclusionsBAV patients develop IE requiring surgery at a younger age than TAV patients, but have significantly better long-term survival. Early detection of BAV is important to prevent IE and provide aggressive surgical treatment should IE occur.

Lactobacillus Endocarditis Complicated by Presumed Vertebral Osteomyelitis and Embolic Stroke

Abstract Lactobacillus species is a facultative anaerobic gram-positive bacillus that is part of the normal flora and is rarely considered pathogenic. In fact, frequently it is used therapeutically as a probiotic. Although normally considered benign, Lactobacillus has been reported to cause bacteremia with and without endocarditis, vertebral osteomyelitis, abscesses, meningitis, peritonitis, and pneumonia. Recommended treatment of choice based on expert opinion for severe infections due to Lactobacillus species endocarditis is high-dose penicillin in combination with an aminoglycoside. In this report, we describe a case in which a 47-year old man with no past medical history develops native aortic valve endocarditis complicated by embolic stroke and presumed lumbar vertebral osteomyelitis.

Native Aortic Valve Endocarditis Complicated by Splenic Infarction and Giant Mitral-Aortic Intervalvular Fibrosa Pseudoaneurysm—A Case Report and Brief Review of the Literature

Background: Pseudoaneurysm of the mitral-aortic intervalvular fibrosa (P-MAIVF) is an unusual complication related to various injuries or conditions which involve the mitro-aortic region; it communicates with the left ventricular outflow tract and is associated with a high-risk of redoubtable complications or sudden death. The cerebral and splenic localizations are frequently seen as manifestations of systemic embolism in infective endocarditis. Currently, there are no specific recommendations related to the diagnosis, management, treatment, or further evolution of patients with P-MAIVF and concomitant splenic infarction. This paper presents the case of a 43-year-old Caucasian woman with a late diagnosis of mixed bicuspid aortic valve disease, affected by an under-detected and undertreated episode of infective endocarditis leading to asymptomatic P-MAIVF. Prime clinical and imagistic diagnosis of splenic infarction indicated further extended investigations were required to clarify the source of embolism. Methods: Integrated multimodality imaging techniques confirmed the unexpected diagnosis of P-MAIVF. Results: The case had a fatal outcome following an uncomplicated yet laborious cardiac surgery. Patient death was attributed to a malignant ventricular arrhythmia. Conclusion: The present case raises awareness by highlighting an unexplained and unexpected splenic infarction association with P-MAIVF as a result of infective endocarditis related to mixed bicuspid aortic valve disease.

Treatment of Complicated Prosthetic Aortic Valve Endocarditis with Annular Involvement with the “Calamari” Technique

Objective: Aortic annular erosion and abscess formation are serious complications of native and prosthetic aortic valve endocarditis. The management of these lesions is difficult due to extensive t...

Incidence and Surgical Outcomes of Patients With Native and Prosthetic Aortic Valve Endocarditis

The aim of this study was to retrospectively evaluate the incidence and surgical outcomes of patients with native infective endocarditis (IE) and prosthetic aortic valve endocarditis (PVE) over the past decade at a single institution. Between January 2005 and December 2015, 289 patients (mean age, 63.3 ± 14.2 years) suffering from native IE (n= 186) and PVE (n= 103) of the aortic valve underwent surgical procedures. Perioperative data were acquired retrospectively for statistical analysis. During the study period the mean incidence of endocarditis increased from 22.0 ± 4.2 (2005-2009) to 29.8 ± 10.1 (2010-2015) cases per year. In-hospital mortality was significantly increased in PVE (22.3%) versus IE (9.1%) patients (P < .001). In elective cases in-hospital mortality between the 2 groups was comparable (2.2% vs 4.6%; P= .288). Multivariate analysis identified urgent surgery (odds ratio [OR], 6.461; 95% CI, 1.941-21.509; P= .002), mitral regurgitation II (OR, 4.230; 95% CI, 1.249-14.331; P= .021), previous homograft operation (OR, 66.096; 95% CI, 2.369-1844.272; P= .0.14), and left ventricular ejection fraction < 40% (OR, 8.267; 95% CI, 1.931-35.388; P= .004) as independent risk factors for in-hospital mortality, whereas pathogen identification by preoperative blood cultures (OR, .228; 95% CI, 0.063-0.817; P= .023) was found to be independently protective. Surgery for native IE and PVE of the aortic valve may be performed with satisfactorily results at experienced cardiac surgical centers. In comparison PVE patients suffer from a more than twice as high in-hospital mortality, more postoperative complications, and inferior long-term survival. However preoperative identification of causative pathogens in IE and PVE allows for improved in-hospital survival.

Native aortic valve endocarditis with Morganella morganii in a patient with multiple myeloma and valvular amyloidosis: a case report

BackgroundPatients with multiple myeloma (MM) are known to be immune incompetent and experience higher incidences of infectious diseases. However, infective endocarditis (IE) is rarely observed in patients with MM and Morganella morganii (M. morganii) has rarely been associated with IE.Case presentationA 72-year-old female receiving 4th line treatment for MM presented with fever and concomitant confusion. Urinary culture revealed growth of Escherichia coli, wherefore broadspectrum penicillin and high-dose corticosteroids were initiated. However, blood cultures showed growth of M. morganii. Fluoroquinolone was added due to penicillin-resistance of the Morganella species. Two days after admission, the patient acutely deteriorated with hemodynamic instability. Gentamicin and high dose corticosteroids were added. Echocardiography showed marked aortic valve vegetation with severe aortic valve regurgitation, leading to the diagnosis of bacterial endocarditis of the native aortic valve. Shortly after diagnosis, the patient died. At autopsy, vegetation with gram-negative rods in the native aortic valve was observed, confirming the diagnosis of M. morganii-endocarditis. Additional staining for amyloid confirmed advanced light-chain (AL) amyloidosis with extensive amyloid depositions of the aortic valve and valvular damage as complications of her MM.ConclusionsOur case suggests that IE with M. morganii was facilitated by the combination of the cardiac amyloidosis with valvular impairment and the profound immune deficiency caused by the several chemo-immunomodulatory treatment lines and the MM itself. This case further illustrates that awareness for rare opportunistic infections in an era with growing potential of combined chemoimmunotherapy is warranted.

Prosthetic valve endocarditis: A challenging complication of prosthetic valves.

This study aims to evaluate the surgical outcomes of prosthetic valve endocarditis. A total of 21 patients (6 males, 15 females; mean age 58.9±12.6 years; range, 33 to 79 years) who were surgically treated for prosthetic valve endocarditis between January 2013 and January 2018 were retrospectively analyzed. Surgical indications included persistent fever for more than seven days after antibiotherapy, congestive heart failure refractory to medical treatment, vegetations larger than 1 cm on echocardiography, the presence of fungal endocarditis, severe valvular leak and valvular dysfunction, and staphylococcal prosthetic valve endocarditis. Five patients had previous aortic valve replacement and three of the aortic prostheses were re-replaced. Two patients had coexisting native mitral valve endocarditis and double valve replacement was done. Thirteen patients had previous mitral valve replacement and 12 of the mitral prostheses were re-replaced. One patient had coexisting native aortic valve endocarditis and double valve re-replacement was done. Three patients had previous aortic valve replacement + mitral valve replacement. Mitral valve endocarditis was diagnosed in two patients and these patients had only mitral valve re-replacement. The other patient had double valve endocarditis, and double valve replacement was done. The mean time from the first operation to the development of endocarditis was 7.3±5.7 years. Of five lost patients, two died from multiple organ failure, one from low cardiac output, one from pneumonia, and one from respiratory failure. Radical resection of the infected tissues is critical to achieve favorable surgical outcomes. Single valve replacement of the infected valve may be preferred in patients having previous double valve replacement. Mechanical valves or bioprostheses can be used for re-replacement procedures.

AORTIC ROOT INFECTION WITH AORTOCAVITARY FISTULA: A RARE PRESENTATION OF NATIVE VALVE GEMELLA MORBILLORUM ENDOCARDITIS

Gemella morbillorum is a type of gram positive cocci that rarely causes infective endocarditis. We present a patient with native aortic and pulmonic valve endocarditis complicated by aorto-right ventricular fistula. A previously healthy, 33-year-old Spanish-speaking male who moved to the United

An Atlantic Canada case of disseminated Streptococcus equi subspecies zooepidemicus infection

Streptococcus equi subspecies zooepidemicus infections in humans can be contracted through contact with domestic animals or unpasteurized dairy products. Although infection in humans is rare, the course can be fulminant. We describe the case of a 75-year-old immunocompetent male who developed disseminated disease with bacteremia, native aortic valve endocarditis, suppurative pericarditis with cardiac tamponade, meningitis, and bilateral endophthalmitis. Despite treatment with pericardial drain placement, intravenous ceftriaxone, and rifampin, the patient unfortunately did not survive. To date, reported cases of disseminated infection by S. equi subsp zooepidemicus are few. Furthermore, with review of the literature, this case demonstrates the broadest organ system involvement reported. Of interest, previous studies have suggested an affinity of this organism for certain organ systems and this case corroborates an emerging association of S. equi subsp zooepidemicus with endophthalmitis. In addition, this is the second Canadian case of documented human infection, with both cases being similar in clinical features, presentation, and geographical location. This case report should serve to warn clinicians about complications and sites of haematogenous seeding in the setting of disseminated S. equi subsp zooepidemicus infections.

Sudden cardiac death due to coronary artery embolism secondary to native aortic valve endocarditis in a young adult

BackgroundSystemic embolism is a common complication of infective endocarditis, most frequently involving the central nervous system, spleen, kidney, liver, and iliac or mesenteric arteries, but embolisation to coronary artery causing sudden cardiac death is infrequently encountered.Case presentationA case of a 45-year-old male who had a coiling procedure for anterior communicating artery aneurysm 6 weeks prior to his death. He was asymptomatic until a week prior to his death. The decedent had a fever and was treated for urinary tract infection with oral cefuroxime. He had a sudden onset of breathlessness and died at his home. Post mortem examination revealed a dilated aortic valve with vegetation. Part of the vegetation dislodged in the left coronary ostium and caused luminal occlusion. The left kidney showed scarred surface and poorly demarcated corticomedullary junction. However, the right kidney and urinary bladder were unremarkable. Microscopic examination revealed the septic thrombus both on the valve and in the left coronary ostium extended to the left main stem coronary artery. However, there was no evidence of myocardial ischemia. Blood culture grew Enterococcus faecalis which are usually associated with intravenous procedure and urinary tract infection. The culture from the vegetation also grew Enterococcus species. The left kidney also showed microscopic evidence of chronic pyelonephritis.ConclusionThis case highlights the rare complication of infective endocarditis which caused sudden cardiac death.

Staphylococcus lugdunensis: The “Lyon Heart” Pathogen

Abstract Staphylococcus lugdunensis is a coagulase-negative Staphylococcus capable of causing infective endocarditis on native as well as prosthetic valves and implanted cardiac devices. It causes acute disease clinically indistinguishable from that caused by Staphylococcus aureus. Bacteremic infections with S. lugdunensis have a high incidence of associated infective endocarditis. Many S. lugdunensis isolates are exquisitely sensitive to penicillin G. Endocarditis caused by S. lugdunensis frequently requires surgical intervention and has a high mortality rate. Case 1: A 48-year-old woman with mitral valve prolapse, S. lugdunensis bacteremia and mitral valve endocarditis. She underwent emergent mitral valve replacement and completed treatment with intravenous nafcillin. Case 2: A 31-year-old woman with spontaneous S. lugdunensis bacteremia and tricuspid valve endocarditis. She was successfully treated medically with 6 weeks of intravenous nafcillin. Case 3: A 44-year-old man with S. lugdunensis endocarditis on congenital bicuspid aortic valve with severe aortic insufficiency. He underwent emergent aortic valve replacement and successfully completed 6 weeks of intravenous nafcillin. Case 4: A 37-year-old woman with spontaneous S. lugdunensis bacteremia and native aortic valve endocarditis. She was successfully treated medically with 6 weeks of intravenous vancomycin. Case 5: A 57-year-old woman with hemodialysis catheter-related S. lugdunensis bacteremia and native mitral valve endocarditis. She was successfully treated medically with 6 weeks of intravenous cefazolin. Staphylococcus lugdunensis is a unique coagulase-negative Staphylococcus first identified in Lyon, France, the modern name for the Roman city of Lugdunum, ergo the organism's name. Since its identification, S. lugdunensis has been described as a “Lion among coagulase-negative staphylococci” and as “a dangerous wolf in sheep's clothing” because of the tendency of clinicians to initially discount positive blood cultures with “coagulase-negative staphylococci” as probable skin contaminants and thereby delay appropriate antimicrobial therapy. We report 5 patients with S. lugdunensis endocarditis and review the adult literature for other reported cases.