Joseph E. Geraci

Prosthetic Valve Endocarditis

Prosthetic valve endocarditis is an infrequent but serious complication of cardiac valve replacement. The overall frequency of prosthetic valve endocarditis is approximately 2%. The frequency of early-onset and late-onset infections is 0.78% and 1.1%, respectively. Staphylococci are the most common isolate from patients with early-onset infection, accounting for 47.5% of the total number of isolates. Staphylococcus epidermidis causes 27% of these staphylococcal infections. Among patients with late-onset infection, streptococci are the predominant microorganism, constituting 42% of the total number of isolates from patients in this group. The overall mortality among patients with prosthetic valve endocarditis is high--59%; the mortality among patients with early- or late-onset infections is 77% and 46%, respectively. Most patients with staphylococcal prosthetic valve endocarditis should undergo cardiac valve replacement in addition to antimicrobial therapy. Closely monitored anticoagulant therapy should be cautiously continued in patients with prosthetic valve endocarditis.

Musculoskeletal manifestations of bacterial endocarditis.

In a retrospective analysis of bacterial endocarditis, 84 of 192 cases (44%) were found to have musculoskeletal manifestations of one or more types. Common manifestations were arthralgias (32 cases), arthritis (26 cases), low back pain (24 cases), diffuse myalgia (16 cases), and myalgias localized to the thigh or calf (11 cases). The joint manifestations typically were monarticular or oligoarticular, and the myalgias were commonly unilateral. No association was found between the pattern of rheumatic symptoms and other clinical manifestations, laboratory tests, or causative bacterial organisms. In 52 patients (27%), musculoskeletal complaints were the first or among the first symptoms of bacterial endocarditis. The frequency and character of these manifestations and their tendency to occur early in the course of the disease indicate that they are an important feature of endocarditis which, if not recognized, may cause a delay in the diagnosis by mimicking a rheumatic disease.

Neurologic manifestations of bacterial endocarditis.

Abstract Twenty-nine percent of patients (110 of 385) with bacterial endocarditis had neurologic involvement. In 60% (65 of 110 patients) the neurologic finding was either the chief complaint or on...

Infective endocarditis—A 25 year overview of diagnosis and therapy

Diagnosis and management of infective endocarditis have significantly changed in the past 25 years. Improved bacteriologic techniques have allowed detection of cases of infective endocarditis caused by unusual organisms. Bactericidal therapy has become available for patients with gram-negative endocarditis and antimicrobial therapy has improved. Echocardiography has become an important diagnostic and management aid, and cardiac valve replacement has dramatically improved the outlook for many patients.

Treatment of streptococcal infective endocarditis

Patients with infective endocarditis caused by penicillin-sensitive streptococci (minimal inhibitory concentration for penicillin of 0.1 microgram/ml or less) may be treated successfully with one of the following regimens: aqueous penicillin G administered intravenously for four weeks, intravenous aqueous penicillin G for four weeks combined with streptomycin for the first two weeks of therapy, or parenterally administered penicillin plus streptomycin for two weeks. A cure rate of at least 98 percent may be anticipated with each of these regimens. During a 12-year period among 142 patients treated for two weeks with penicillin and streptomycin, one (0.7 percent) had relapse and four (3 percent) had vestibular toxicity. The major advantage of the two-week regimen is that it is more cost-effective than the four-week regimens. The major disadvantage of the use of streptomycin is the relatively low risk of vestibular toxicity. Patients with enterococcal endocarditis were treated initially for four weeks with aqueous penicillin G together with either streptomycin (streptomycin-susceptible enterococci, 36 patients) or gentamicin (streptomycin-resistant enterococci, 20 patients). Compared with patients who had symptoms for less than three months, patients with symptoms for longer than three months had a higher relapse rate (0 percent versus 44 percent; p less than 0.001) and mortality (2.5 percent versus 25 percent; p less than 0.001). Patients with mitral valve endocarditis had a significantly higher relapse rate (25 percent) than patients with aortic valve infection (0 percent; p less than 0.01]. Gentamicin-associated nephrotoxicity was more frequent (p less than 0.001) among patients treated with more than 3 mg/kg per day of gentamicin than among those treated with 3 mg/kg per day or less (100 percent versus 20 percent). Relapse and mortality rates did not differ significantly between patients treated with low-dose or high-dose gentamicin regimens. Patients who have had symptoms of enterococcal endocarditis for longer than three months or perhaps patients with mitral valve infection should receive at least six weeks of penicillin therapy together with an aminoglycoside; patients without either high-risk factor may be treated successfully for four weeks.

In vitro and in vivo activity of ciprofloxacin against enterococci isolated from patients with infective endocarditis.

In vitro activity of ciprofloxacin against 27 strains of enterococci was inoculum dependent. Using inocula of 10(5) to 10(6) or 10(7) to 10(8) CFU of enterococci per ml, the MICs for 50 and 90% of strains tested increased from 1 to greater than or equal to 128 micrograms of ciprofloxacin per ml with the higher inoculum compared with the lower inoculum. The MBC for 50% of strains tested increased from 2 to greater than 128 micrograms/ml and the MBC for 90% of strains tested increased from 8 to greater than 128 micrograms of ciprofloxacin per ml with the lower and higher inocula, respectively. The combination of penicillin-gentamicin was more effective in vitro than the combination of ciprofloxacin-gentamicin against the low or high inoculum of enterococci. Using two strains of enterococci, we studied the efficacy of ciprofloxacin in the treatment of enterococcal experimental endocarditis in rabbits. Ciprofloxacin used alone or combined with gentamicin was significantly less effective (P less than 0.01) than procaine penicillin alone or procaine penicillin combined with gentamicin for the treatment of enterococcal experimental endocarditis. The combination of ciprofloxacin-procaine penicillin was not a more effective therapy than procaine penicillin alone.

Antimicrobial therapy of experimental endocarditis caused by nutritionally variant viridans group streptococci.

Rabbits with nutritionally variant viridans group streptococcal experimental endocarditis were treated three times daily for 3 days with procaine penicillin (1.2 X 10(6) U) alone or together with low-dose streptomycin (2 mg/kg), high-dose streptomycin (8 mg/kg), low-dose gentamicin (0.32 mg/kg), or high-dose gentamicin (1.05 mg/kg). The mean 0.5-h serum concentrations of streptomycin were 5.3 and 22.5 micrograms/ml in the low- and high-dose group, respectively, and the concentrations of gentamicin were 0.7 and 2.5 micrograms in the low- and high-dose groups, respectively. The combination of procaine penicillin with each dose of aminoglycoside was significantly more effective (P less than 0.001) than was procaine penicillin alone. In combination with procaine penicillin, the higher dose of streptomycin was significantly more effective (P less than 0.02) than the lower dose of streptomycin. The higher dose of streptomycin was not significantly more effective than either dose of gentamicin. The results of treatment with the high or low dose of gentamicin were virtually identical.

Streptococcus mutans endocarditis.

Abstract Nine patients withStreptococcus mutansendocarditis were seen between 1966 and 1973. They had the typical clinical picture of subacute bacterial endocarditis, with fever, heart murmur, and ...

Treatment of streptomycin-susceptible enterococcal experimental endocarditis with combinations of penicillin and low- or high-dose streptomycin.

We used two strains of streptomycin-susceptible enterococci (MIC, 64 and 128 micrograms of streptomycin per ml, respectively) isolated from patients with infective endocarditis. When combined with penicillin, 20 micrograms of streptomycin per ml killed both strains synergistically in vitro whereas combinations of 5 and 10 micrograms of streptomycin per ml did not act synergistically against either strain. By using the rabbit model of enterococcal experimental endocarditis, animals were treated for 3 days with procaine penicillin (1.2 X 10(6) U intramuscularly three times daily) together with low-dose streptomycin (3.5 mg/kg) or high-dose streptomycin (10 mg/kg) intramuscularly three times daily. The peak concentrations of streptomycin in serum at 0.5 h were 9.2 and 26.8 micrograms/ml in the low- or high-dose group, respectively. When combined with procaine penicillin, both dosages of streptomycin were more effective (P less than 0.01) than procaine penicillin alone for the treatment of enterococcal experimental endocarditis. There was no significant difference in the efficacy of procaine penicillin plus low-dose streptomycin versus procaine penicillin plus high-dose streptomycin therapy of enterococcal experimental endocarditis.

Bactericidal Activity of Combinations of Penicillin or Clindamycin with Gentamicin or Streptomycin Against Species of Viridans Streptococci

Checkerboard bactericidal studies were performed with two strains each of Streptococcus mitis, S. salivarius, and S. sanguis, and the results were analyzed by the use of isobolograms. Synergy between penicillin and streptomycin or gentamicin was demonstrated with four strains, representing two of S. salivarius, one of S. sanguis, and one of S. mitis; the remainder were either too susceptible or too resistant to be analyzed. Clindamycin with streptomycin or gentamicin acted synergistically with three strains, representing two of S. sanguis and one of S. salivarius; the remainder were either too susceptible or too resistant to be analyzed.