Getting to the heart of the problem: serological and molecular techniques in the diagnosis of infective endocarditis

Epidemiological Profile and Mortality of Infective Endocarditis Over the Past Decade: A Systematic Review and Meta-Analysis of 133 Studies

Infective endocarditis (IE) is an increasingly prevalent condition with relatively high mortality, whose epidemiology has become more complex with an aging population, an increased number of comorbidities, and an increasing incidence of health-care associated IE. Epidemiological data on the causative microorganisms of IE, prevalence of involvement of the different cardiac valves, and IE-associated mortality are clinically relevant. Eligible studies were identified through a systematic search of PubMed/MEDLINE database from 2010 to 2020, and a random effects model meta-analysis was conducted. 133 studies comprising 132,584 patients from six continents were included in this systematic review. The most common causative agents were Staphylococci species in 36% of cases, followed by Streptococci species (26%) and Enterococci species (10%). Out of studies that provided further speciation, the predominant species was Staphylococcus aureus with an incidence of 29%, followed by Viridans group Streptococcus (12%). The short-term mortality rate (defined as in-hospital or 30-day mortality) was 17%. The highest mortality was reported in studies from Latin America with a mean mortality rate of 33% and the lowest mortality was reported in studies from Oceania at 13%. The aortic valve was the most commonly affected valve (46%), followed closely by the mitral valve (43%). The prevalence of tricuspid valve IE was 7% and multivalvular IE occurred in 14% of cases. Our study highlights a shift in epidemiological profile of IE over the last decade with S. aureus identified as the most common causative microorganism of IE. PROTOCOL REGISTRATION: PROSPERO CRD42024602342.

Polymicrobial Infective Endocarditis: Clinical Features and Prognosis

To describe the profile of left-sided polymicrobial endocarditis (PE) and to compare it with monomicrobial endocarditis (ME).Among 1011 episodes of left-sided endocarditis consecutively diagnosed in 3 tertiary centers, between January 1, 1996 and December 31, 2014, 60 were polymicrobial (5.9%), 821 monomicrobial (81.7%), and in 123 no microorganism was detected (12.2%). Seven patients (0.7%) were excluded from the analysis because contamination of biologic tissue could not be discarded. The authors described the clinical, microbiologic, echocardiographic, and outcome of patients with PE and compared it with ME.Mean age was 64 years SD 16 years, 67% were men and 30% nosocomial. Diabetes mellitus (35%) were the most frequent comorbidities, fever (67%) and heart failure (43%) the most common symptoms at admission. Prosthetic valves (50%) were the most frequent infection location and coagulase-negative Staphylococci (48%) and enterococci (37%) the leading etiologies. The most repeated combination was coagulase-negative Staphylococci with enterococci (n = 9). Polymicrobial endocarditis appeared more frequently in patients with underlying disease (70% versus 56%, P = 0.036), mostly diabetics (35% versus 24%, P = 0.044) with previous cardiac surgery (15% versus 8% P = 0.049) and prosthetic valves (50% versus 37%, P = 0.038). Coagulase-negative Staphylococci, enterococci, Gram-negative bacilli, anaerobes, and fungi were more frequent in PE. No differences on age, sex, symptoms, need of surgery, and in-hospital mortality were detected.Polymicrobial endocarditis represents 5.9% of episodes of left-sided endocarditis in our series. Despite relevant demographic and microbiologic differences between PE and ME, short-term outcome is similar.