Viridans streptococcal endocarditis: clinical, microbiological, and echocardiographic correlations

Infections caused by species within the viridans streptococci have been associated with different clinical characteristics. We studied 36 patients with viridans streptococcal endocarditis. Complications were seen in 10 (32%) of 31 patients with native valve endocarditis and four (80%) of five with prosthetic valve endocarditis and included death in two, valve replacement in six, persistent infection in three, emboli in two, and congestive heart failure in nine. Two-dimensional echocardiograms demonstrated vegetations in 26 (72%) of 36, flail mitral valves in seven, disruption of aortic valve prosthesis in one, and perivalvular abscesses in three (two Streptococcus sanguis I and one Streptococcus intermedius I). All twelve patients with native valve endocarditis who suffered complications had vegetations detected by two-dimensional echocardiography, whereas seven patients with native valve endocarditis without vegetations, as detected by two-dimensional echocardiography, had no complications (P = .03). We found no significant correlation between streptococcal species and clinical outcome. To confirm our identifications, we sent 16 identical viridans streptococcal endocarditis isolates to five institutions; only three of 16 were identified as the same species by all five institutions. We conclude that viridans streptococcal endocarditis can be associated with a virulent clinical course and that there is marked variability in species designations of individual strains by different laboratories.     

Development of aortic valvular vegetations during appropriate antibiotic therapy. Demonstration through serial echocardiograms.

The development of echocardiographically demonstrable vegetations on cardiac valves while the patient is receiving appropriate antibiotic therapy has not been previously reported. We report a case of alpha-hemolytic streptococcal endocarditis involving the aortic valve. Echocardiographically visualized vegetations were noted to occur on the 11th day of hospitalization. We discuss the role of serial echocardiograms in the management of patients with bacteremias and suspected endocarditis but absence of vegetations on the initial echocardiogram.     

Emboli in infective endocarditis: the prognostic value of echocardiography

OBJECTIVE: To determine whether vegetations visualized on two-dimensional echocardiography are an independent risk factor for the development of subsequent emboli in patients with infective endocarditis and to assess the timing of emboli relative to the initiation of antimicrobial therapy. DESIGN: Investigator-blinded, retrospective incidence cohort study. SETTING: Tertiary referral center. PATIENTS: Patients with left-sided native valve infective endocarditis who had two-dimensional echocardiography within 72 hours of beginning antimicrobial therapy. MEASUREMENTS AND MAIN RESULTS: The crude incidence rate of first embolic events in patients receiving antimicrobial therapy was 6.2 per 1000 patient-days (95% CI, 4.2 to 9.2). The rates in patients with and without vegetations were 7.1 and 4.9 per 1000 patient-days, respectively (incidence rate ratio, 1.4; 95% CI, 0.6 to 3.3). The relation between vegetations and risk for emboli was microorganism-dependent: Stratified incidence rate ratios were 6.9 (95% CI, 1.1 to 42.5; P less than 0.05) and 1.0 (95% CI, 0.2 to 3.9) for viridans streptococcal and Staphylococcus aureus endocarditis, respectively. The rate of first embolic events diminished over time (P less than 0.001), falling from 13 per 1000 patient-days during the first week of therapy to less than 1.2 per 1000 patient-days after completion of the second week of therapy. CONCLUSIONS: Overall, the presence of vegetations on echocardiography was not associated with a significantly higher risk for embolus in patients with left-sided native valve infective endocarditis. The relative risk for embolic events associated with echocardiographically visualized vegetations may be microorganism-dependent, with a significantly increased risk seen only in patients with viridans streptococcal infection. The rate of embolic events declines with time after initiation of antimicrobial treatment.     

Endocarditis of the pulmonary valve complicating interventricular communication. Echocardiographic detection

A 29-year old woman known to have Roger's disease was hospitalized for streptococcal endocarditis with pulmonary embolism and cerebral vascular accident. Echocardiography demonstrated vegetations on the pulmonary valve, and this was confirmed at surgery. Pulmonary valve endocarditis is a rare lesion sometimes occurring as a complication of congenital malformations with ventricular septal defect. Its prognosis is governed not so much by bacterial resistance or haemodynamic repercussions as by the risk of septic pulmonary embolism or systemic embolism. Prophylaxis is essential to avoid this dangerous complication.     

Group B streptococcal endocarditis: report of seven cases and review of the literature, 1962-1985

Infective endocarditis is an uncommon manifestation of group B streptococcal disease. Seven cases of group B streptococcal endocarditis are reported herein. Another fifty-five cases published in the literature since 1962 are reviewed: the male to female ratio was 1.4:1. The average age was 53.8 years, and 45% of patients were 60 years of age or older. Two cases of nonsocomial endocarditis and two cases of polymicrobial endocarditis were identified. There were five cases of prosthetic valve endocarditis. Mitral and aortic valvular involvement were present in 48% and 29% of cases, respectively. Underlying heart disease was found in more than half of the cases. Rheumatic heart disease was the commonest underlying cardiac condition. Noncardiac underlying conditions included diabetes mellitus, alcoholism, pregnancy, intravenous drug abuse, and genitourinary disease. Onset was varied as was initial presentation of the disease. Large arterial thrombi were common. Overall mortality was 43.5%. Penicillin is the treatment of choice for group B streptococcal endocarditis. However, based on in vitro and in vivo studies as well as case reports, some authors feel that the combination of penicillin and an aminoglycoside is a superior regimen. Cephalothin or vancomycin are alternatives for patients who are allergic to penicillin.     

Malignant group B streptococcal endocarditis associated with saline-induced abortion.

A 20-year-old woman developed acute group B streptococcal endocarditis following saline-induced abortion. In the pre-antibiotic era, most cases of group B streptococcal endocarditis occurred in parturient or postabortal women. Currently, this disease is rarely described in obstetrical patients, and no previous cases following saline-induced abortion have been reported. Purulent pericarditis and a perivalvular abscess were present in our patient and represent only the second instance in which these findings have been documented in this disease.     

Replacement of the mitral valve in an infant with group B streptococcal endocarditis

Endocarditis due to group B streptococcus is very rare in infants, and may be associated with significant morbidity and mortality. Review of the literature reveals only a single reported case of an infant with this type of streptococcal endocarditis involving the mitral valve. This infant had underlying congenital heart disease, and died shortly after catheterization. We now report group B streptococcal endocarditis occurring in an infant with a structurally normal heart who was treated successfully by replacement of the mitral valve.     

Endocardite tricuspide du post-partum à streptocoque B

The B streptococcal endocarditis are very rare. They primarily affect the left heart valves, the achievement of the tricuspid valve is exceptional. We report a young patient aged of 36 years who presented in postpartum a tricuspid endocarditis with streptococcus B. She was treated by third-generation cephalosporin and aminoglycoside. The evolution after 5 days of antibiotic therapy was marked by a rapid valvular destruction with worsening tricuspid insufficiency leading to death of the patient. This is the 23rd case of tricuspid endocarditis streptococcal B reported in the literature. The mortality of this disease reached 36% in the absence of surgical treatment. The medico-surgical approach is the treatment of choice for these patients.     

Aspergillus fumigatus pacemaker lead endocarditis: a case report and review of the literature

The diagnosis of fungal endocarditis requires a high index of clinical suspicion. Rarely, pacemaker implantation may be a risk factor for the development of fungal endocarditis. A 71-year-old man with a history of multiple transvenous pacemaker manipulations and fever of an uncertain source is described. A diagnosis of culture-negative pacemaker endocarditis was established only after repeat transthoracic echocardiography. Amphotericin B was instituted; however, the patient developed a cerebral infarct and died. Postmortem examination demonstrated Aspergillus fumigatus within a large pacemaker lead thrombus, tricuspid and aortic valve vegetations, and septic pulmonary and renal emboli. The present report describes the clinical and pathological features of a rare case of Aspergillus fumigatus pacemaker lead endocarditis and suggests that serial echocardiograms may be effective in the early detection of pacemaker lead vegetations. The diagnostic features and therapeutic management of pacemaker lead endocarditis are reviewed.     

Endocarditis with myocardial abscesses and pericarditis in an adult: group B Streptococcus as a cause.

Group B beta-hemolytic Streptococcus, S agalactiae, is an uncommon cause of endocarditis in adults. We present the clinical, laboratory, and postmortem findings of an adult patient with group B streptococcal endocarditis and major arterial emboli. What to our knowledge are previously unreported features are purulent pericarditis and myocardial abscesses. Twenty-five cases of endocarditis caused by group B Streptococcus that are reported in the literature are reviewed.     

Group B streptococcal endocarditis of tricuspid valve

We report three cases of group B streptococcal endocarditis of the tricuspid valve. Two patients were intravenous drug abusers. In the literature review, and including our cases, ten patients had group B streptococcal endocarditis of the tricuspid valve. Half of the patients were intravenous drug abusers. Four of the other patients had underlying conditions. All patients were treated with a penicillin with or without an aminoglycoside. Three patients underwent tricuspid valve surgery. The overall mortality was 20 percent. Both patients who died received medical therapy only.     

Comparison of single doses of amoxicillin or of amoxicillin-gentamicin for the prevention of endocarditis caused by Streptococcus faecalis and by viridans streptococci

Recent recommendations for the prophylaxis of endocarditis in humans have advocated single doses or short courses of antibiotic combinations (beta-lactam plus aminoglycoside) for susceptible patients in whom enterococcal bacteremia might develop or for patients at especially high risk of developing endocarditis (e.g., patients with prosthetic cardiac valves). We tested the prophylactic efficacy (in rats with catheter-induced aortic vegetations) of single doses of amoxicillin plus gentamicin against challenge with various streptococcal strains (two strains of Streptococcus faecalis, one of Streptococcus bovis, and three of viridans streptococci); we then compared this efficacy with that of single doses of amoxicillin alone. Successful prophylaxis against all six strains was achieved with single doses of both amoxicillin alone and amoxicillin plus gentamicin. This protection, however, was limited, for both regimens, to the lowest bacterial-inoculum size producing endocarditis in 90% of control rats and was not extended to higher inocula by using the combination of antibiotics. We concluded that a single dose of amoxicillin alone was protective against enterococcal and nonenterococcal endocarditis in the rat, but that its efficacy was limited and could not be improved by the simultaneous administration of gentamicin.     

Isolated pulmonic valve endocarditis caused by group B streprococcus (Streptococcus agalactiae)--a case report and literature review

The pulmonic valve is the least commonly involved valve in infective endocarditis. Pulmonic valve endocarditis is usually associated with tricuspid valve endocarditis, and isolated pulmonic valve endocarditis is exceedingly rare. The predisposing factors for developing pulmonic valve endocarditis include a congenitally anomalous pulmonic valve, intravenous drug abuse, and the presence of indwelling intravenous or flow-directed pulmonary artery catheters. More cases of group B streptococcus endocarditis are being reported. The risk factors for group B streptococcus endocarditis include diabetes mellitus, cancer, alcoholism, malnutrition, immunocompromised status, intravenous drug abuse, postpartum and postabortion states, and underlying valvular disease. The vegetations of this type of endocarditis are usually large and have a higher tendency to result in embolism. The presentation of group B streptococcus endocarditis is usually acute and may result in rapid valve destruction if not treated promptly. A case of isolated pulmonic valve endocarditis caused by group B streptococcus, Streptococcus agalactiae, is presented that was diagnosed with multiplane transesophageal echocardiography in a 40-year old, alcoholic, malnourished man, who was successfully treated with intravenous penicillin G. The literature on the isolated pulmonic valve endocarditis caused by group B streptococcus is reviewed.     

Group B streptococcal infective endocarditis

From 1970 to 1983, five patients with group B streptococcal endocarditis were treated at the Mayo Clinic, Rochester, Minn. The minimal inhibitory concentration and the minimal bactericidal concentration of penicillin were 0.09 microgram/mL or less and 1.56 micrograms/mL or less, respectively. The in vitro activity of cefazolin against group B streptococci was similar to that of penicillin. In three of the five cases, penicillin and streptomycin acted synergistically in vitro against group B streptococci. Four of the five patients were cured, three by use of an aminoglycoside combined with penicillin, ampicillin, or vancomycin. Three of the five patients had multiple large systemic emboli, and one of the three died of brain-stem infarct. Penicillin alone or in combination with an aminoglycoside is effective therapy for group B streptococcal endocarditis. Patients unable to tolerate penicillin may be treated with cefazolin or vancomycin. Clindamycin therapy should be avoided in patients with endocarditis caused by strains that are tolerant in vitro to clindamycin.     

Fibrinolytic therapy in bacterial endocarditis: Experimental studies in dogs

An investigation was undertaken to assess the value of addingstreptokinase therapy to standard penicillin treatment of artificiallyinduced infective endocarditis due to Streptococcus sanguis.In pigs a low-grade infection could be induced which closelysimulated streptococcal endocarditis in man, but for technicalreasons this model proved unsatisfactory for further experimentation.In dogs the induction of S. sanguis endocarditis produced amore severe illness with a short natural history. Dogs weredivided into two groups, one treated with penicillin alone,the other with penicillin and streptokinase. A five-day cdurse,in which twice daily injections of an acylated streptokinase-plasminogencomplex were given, caused a substantial reduction in the sizeof vegetations and possibly a higher proportion of cures andless damage to the valves. Infarction of the brain, almost certainlydue to embolism, was significantly greater in the streptokinasetreated group, but the same was not true of the kidneys. Thepossible value of such treatment for certain kinds of bacterialendocarditis in man, especially in the right side of the heart,is discussed.     

Improved detection of infective endocarditis with transesophageal echocardiography.

The incremental advantage of transesophageal echocardiography was determined by comparing results of paired transthoracic and transesophageal echocardiographic examinations performed in 61 patients for evaluation of suspected infective endocarditis. According to clinical and pathologic data, 31 of 61 (51%) patients had finding that were positive for infective endocarditis. Studies were graded as positive or negative for vegetations and were also graded for image quality. The sensitivity of transesophageal echocardiography in detecting vegetations was 88% versus 30% for transthoracic studies (p less than 0.01). For patients with aortic valve infective endocarditis, transesophageal sensitivity was 88% versus 25% for transthoracic sensitivity, because transesophageal echocardiography successfully separated vegetations from chronic valve disease caused by sclerosis or calcification (p less than 0.01). For patients with mitral valve infective endocarditis, transesophageal sensitivity was 100% versus 50% for transthoracic sensitivity, because transesophageal echocardiography distinguished vegetations from myxomatous changes or detected vegetations on prosthetic valves (p less than 0.01). Thus transesophageal echocardiography improves recognition of infective endocarditis, particularly in the presence of underlying valvular disease.     

Unusual endocarditis: "rare bug, rare site"

A 27-year-old man was diagnosed with infective endocarditis due to Streptococcus agalactiae. Large vegetations were seen on the anterior mitral valve leaflet and also on the right ventricular side of a membranous ventricular septal defect. Streptococcus agalactiae is a rare cause of endocarditis, and it is very rare to find large vegetations around ventricular septal defect. The authors present this interesting case of unusual endocarditis with vegetations in both the right and left heart. This case is the first reported case of infective endocarditis involving the left and the right sides of the heart at the same time in a nonintravenous drug user.     

Reliability and clinical relevance of detection of vegetations by echocardiography in bacterial endocarditis.

The efficacy of M-mode echocardiography in identifying vegetations and the clinical relevance of such a finding were evaluated in 36 patients with bacterial endocarditis, 18 of whom had pre-existing valvar lesions. Of 22 patients with vegetations demonstrated by echocardiography, 21 had major complications of bacterial endocarditis and eight died, whereas only eight of the 14 patients without detectable vegetations had similar complications and only two died. Nine of the 11 patients with pre-existing valvar lesions and echocardiographic evidence of vegetations came to operation or necropsy, and in eight of these the presence of vegetations was confirmed. In the other, none was found at surgery performed after an interval of six months. M-mode echocardiography can reliably detect vegetations in patients with bacterial endocarditis even in the presence of pre-existing valvar lesions, and may permit the identification of a subset of high risk patients who may need early surgery.     

Vegetations in infective endocarditis. Clinical relevance and diagnosis by cross sectional echocardiography.

Cross sectional echocardiography identified vegetations in 45 of 62 (73%) patients who had clinical evidence of active infective endocarditis. The sensitivity of this technique in diagnosing vegetations in infective endocarditis was 93% and the specificity 89%. The predictive value of a positive test was 96% and that of a negative test 80%. Vegetations were detected with a similar frequency on the aortic and mitral valves. The incidence of valvar incompetence, congestive heart failure, and the need for surgical intervention was similar in the patients with and without vegetations. Embolism occurred in 47% of those patients with vegetations and in 12% of those without. The mortality rate was 27% in those with vegetations, and no patient without vegetations died. Thus cross sectional echocardiography is accurate in diagnosing vegetations in patients with infective endocarditis, and this finding identifies patients at high risk of embolic complications and death.     

Group B streptococcal bacteremia in a community teaching hospital

Group B streptococcal bacteremia outside the perinatal setting is not commonly emphasized. This report reviews all episodes of group B streptococcal bacteremia during a four and a half year period in a large community teaching hospital. Fourteen episodes occurred in neonates, four in parturient women, and 28 in other adults. Bacteremic adults were usually elderly with an average age of 68 years. Group B streptococcal bacteremia occurred in adults with various underlying diseases, including diabetes mellitus, liver disease, peripheral vascular disease, and hematologic disease, and in those receiving long-term steroid therapy. Infections causing group B streptococcal bacteremia in adults included decubitus ulcers, pneumonia, endocarditis, cellulitis, arthritis, osteomyelitis, and meningitis. Thirteen of 28 episodes of group B streptococcal bacteremia in adults were hospital-acquired. Overall mortality in adults was 70 percent. Group B streptococcal bacteremia in adults outside of the perinatal setting is associated with significant underlying diseases and has a high mortality.