Cases Of Definite Infective Endocarditis Research Articles

Epidemiologic, clinical, and microbiologic profile of infective endocarditis in Argentina: A national survey. The Endocarditis Infecciosa en la República Argentina–2 (EIRA-2) Study

This study aimed to determine the epidemiologic, clinical, microbiologic characteristics, and inhospital outcome of infective endocarditis (IE) in Argentina and compare the results with those of the 1992 IE national survey. A prospective, multicenter study was conducted in 82 hospitals representing 16 of 24 provinces of Argentina. Patients with diagnosis of IE according to the Duke criteria were surveyed during an 18-month period. From 470 surveyed episodes of IE, 390 cases were classified as definite and 80 as possible IE. The mean age of the definite IE cases was 58.5 +/- 17.3 years; male sex, 70.0%; and male-female ratio, 2.3:1. Pathological evidence of IE was available in 26.2%. There was no previously known heart disease in 35.1%, and the proportion of prosthetic valve IE was 15.9%. Causative microorganisms were streptococci, 38.3% (Streptococcus viridans 27.0%, Streptococcus bovis 5.2%, others 6.1%); enterococci, 10.2%; staphylococci, 36.7% (Staphylococcus aureus 29.8%, coagulase-negative staphylococci 6.9%); HACEK group, 6.1%; fungal, 1.4%; and polymicrobial, 2.0%. Blood culture results were negative in 10.8%. Surgical treatment was performed in 26.2%, and the overall inhospital mortality was 24.6%. Patients from the 2002 survey were older (58.5 +/- 17.3 vs 51.3 +/- 18.7 years, P < .01) and more frequently had underlying heart disease (64.9% vs 55.0%, P < .01): degenerative valve disease (11.5% vs 4.8%, P < .01), congenital heart disease (9.5% vs 4.2%, P < .01), and prosthetic valve IE (15.9% vs 8.5%, P < .01). Conversely, the prevalence of rheumatic valve disease was significantly less than in the 1992 survey (5.4% vs 13.0%, P < .01). The EIRA-2 survey shows that the clinical profile of IE has changed in Argentina. Currently, patients with IE are older and have a higher frequency of underlying heart disease, degenerative valve disease, and prosthetic valve IE than previously. The incidence of staphylococcal IE has increased. Inhospital mortality remains high, suggesting that more aggressive measures are needed for the early identification, prevention, and treatment of IE.

Staphylococcus aureus Native Valve Infective Endocarditis: Report of 566 Episodes from the International Collaboration on Endocarditis Merged Database

Staphylococcus aureus native valve infective endocarditis (SA-NVIE) is not completely understood. The objective of this investigation was to describe the characteristics of a large, international cohort of patients with SA-NVIE. The International Collaboration on Endocarditis Merged Database (ICE-MD) is a combination of 7 existing electronic databases from 5 countries that contains data on 2212 cases of definite infective endocarditis (IE). Of patients with native valve IE, 566 patients [corrected] had IE due to S. aureus, and 1074 patients had IE due to pathogens other than S. aureus (non-SA-NVIE). Patients with S. aureus IE were more likely to die (20% vs. 12%; P < .001), to experience an embolic event (61% [corrected] vs. 31%; P < .001), or to have a central nervous system event (21% [corrected] vs. 13%; P < .001) and were less likely to undergo surgery (26% vs. 39%; P < .001) than were patients with non-SA-NVIE. Multivariate analysis of prognostic factors of mortality identified age (odds ratio [OR], 1.4; 95% confidence interval [CI], 1.1-1.7), periannular abscess (OR, 2.4; 95% CI, 1.0 [corrected] -5.6), heart failure (OR, 3.9; 95% CI, 2.3-6.7), and absence of surgical therapy (OR, 2.3; 95% CI, 1.3-4.2) as variables that were independently associated with mortality in patients with SA-NVIE. After adjusting for patient-, pathogen-, and treatment-specific characteristics by multivariate analysis, geographical region was also found to be associated with mortality in patients with SA-NVIE (P < .001). S. aureus is an important and common cause of IE. The outcome of SA-NVIE is worse than that of non-SA-NVIE. Several clinical parameters are independently associated with mortality for patients with SA-NVIE. The clinical characteristics and outcome of SA-NVIE vary significantly by geographic region, although the reasons for such regional variations in outcomes of SA-NVIE are unknown and are probably multifactorial. A large, prospective, multinational cohort study of patients with IE is now under way to further investigate these observations.

Staphylococcus aureus Endocarditis

The global significance of infective endocarditis (IE) caused by Staphylococcus aureus is unknown. To document the international emergence of health care-associated S aureus IE and methicillin-resistant S aureus (MRSA) IE and to evaluate regional variation in patients with S aureus IE. Prospective observational cohort study set in 39 medical centers in 16 countries. Participants were a population of 1779 patients with definite IE as defined by Duke criteria who were enrolled in the International Collaboration on Endocarditis-Prospective Cohort Study from June 2000 to December 2003. In-hospital mortality. S aureus was the most common pathogen among the 1779 cases of definite IE in the International Collaboration on Endocarditis Prospective-Cohort Study (558 patients, 31.4%). Health care-associated infection was the most common form of S aureus IE (218 patients, 39.1%), accounting for 25.9% (Australia/New Zealand) to 54.2% (Brazil) of cases. Most patients with health care-associated S aureus IE (131 patients, 60.1%) acquired the infection outside of the hospital. MRSA IE was more common in the United States (37.2%) and Brazil (37.5%) than in Europe/Middle East (23.7%) and Australia/New Zealand (15.5%, P<.001). Persistent bacteremia was independently associated with MRSA IE (odds ratio, 6.2; 95% confidence interval, 2.9-13.2). Patients in the United States were most likely to be hemodialysis dependent, to have diabetes, to have a presumed intravascular device source, to receive vancomycin, to be infected with MRSA, and to have persistent bacteremia (P<.001 for all comparisons). S aureus is the leading cause of IE in many regions of the world. Characteristics of patients with S aureus IE vary significantly by region. Further studies are required to determine the causes of regional variation.

Blood Culture-Negative Endocarditis in a Reference Center

To identify the current etiologies of blood culture-negative infective endocarditis and to describe the epidemiologic, clinical, laboratory, and echocardiographic characteristics associated with each etiology, as well as with unexplained cases, we tested samples from 348 patients suspected of having blood culture-negative infective endocarditis in our diagnostic center, the French National Reference Center for Rickettsial Diseases, between 1983 and 2001. Serology tests for Coxiella burnettii, Bartonella species, Chlamydia species, Legionella species, and Aspergillus species; blood culture on shell vial; and, when available, analysis of valve specimens through culture, microscopic examination, and direct PCR amplification were performed. Physicians were asked to complete a questionnaire, which was computerized. Only cases of definite infective endocarditis, as defined by the modified Duke criteria, were included. A total of 348 cases were recorded-to our knowledge, the largest series reported to date. Of those, 167 cases (48%) were associated with C. burnetii, 99 (28%) with Bartonella species, and 5 (1%) with rare, fastidious bacterial agents of endocarditis (Tropheryma whipplei, Abiotrophia elegans, Mycoplasma hominis, Legionella pneumophila). Among 73 cases without etiology, 58 received antibiotic drugs before the blood cultures. Six cases were right-sided endocarditis and 4 occurred in patients who had a permanent pacemaker. Finally, no explanatory factor was found for 5 remaining cases (1%), despite all investigations.Q fever endocarditis affected males in 75% of cases, between 40 and 70 years of age. Ninety-one percent of patients had a previous valvulopathy, 32% were immunocompromised, and 70% had been exposed to animals. Our study confirms the improved clinical presentation and prognosis of the disease observed during the last decades. Such an evolution could be related to earlier diagnosis due to better physician awareness and more sensitive diagnostic techniques. As for Bartonella species, B. quintana was recorded more frequently than B. henselae (53 vs 17 cases). For 18 patients with Bartonella endocarditis, the responsible species was not identified. Species determination was achieved through culture and/or PCR in 49 cases and through Western immunoblotting in 22. Comparison of B. quintana and B. henselae endocarditis revealed distinct epidemiologic patterns. The 2 cases due to T. whipplei reflect the emerging role of this agent as a cause of infective endocarditis. Because identification of the bacterium was possible only through analysis of excised valves by histologic examination, PCR, and culture on shell vial, the prevalence of the disease might be underestimated. Among patients who received antibiotic drugs before blood cultures, 4 cases (7%) were found to be associated with Streptococcus species (2 S. bovis and 2 S. mutans) through 16S rDNA gene amplification directly from the valve, which shows the usefulness of this technique in overcoming the limitations of previous antibiotic treatment. Right-sided endocarditis occurred classically in young patients (mean age, 36 yr), intravenous drug users in 50% of cases, and suffering more often from embolic complications. Finally, 5 cases without etiology or explaining factors were all immunocompetent male patients with previous aortic valvular lesions, and 3 of the 5 presented with an aortic abscess. Further investigations should be focused on this group to identify new agents of infective endocarditis.

Prognostic Factors in 61 Cases of Staphylococcus aureus Prosthetic Valve Infective Endocarditis from the International Collaboration on Endocarditis Merged Database

Staphylococcus aureus prosthetic valve infective endocarditis (SA-PVIE) is associated with a high mortality rate, but prognostic factors have not been clearly elucidated. The International Collaboration on Endocarditis merged database (ICE-MD) contained 2212 cases of definite infective endocarditis (as defined using the Duke criteria), 61 of which were SA-PVIE. Overall mortality rate was 47.5%, stroke was associated with an increased risk of death, and early valve replacement was not associated with a significant survival benefit in the whole population; however, patients who developed cardiac complications and underwent early valve replacement had the lowest mortality rate (28.6%).