Infective endocarditis epidemiology over five decades: a systematic review

Abstract

Aims: To Assess changes in infective endocarditis (IE) epidemiology over the last 5 decades.

Methods and results: We searched the published literature using PubMed, MEDLINE, and EMBASE from inception until December 2011.

Data from: Einstein Medical Center, Philadelphia, PA were also included. Criteria for inclusion in this systematic review included studies with reported IE microbiology, IE definition, description of population studied, and time frame. Two authors independently extracted data and assessed manuscript quality. One hundred sixty studies (27,083 patients) met inclusion criteria. Among hospital-based studies (n=142; 23,606 patients) staphylococcal IE percentage increased over time, with coagulase-negative staphylococcus (CNS) increasing over each of the last 5 decades (p<0.001) and Staphylococcus aureus (SA) in the last decade (21% to 30%; p<0.05). Streptococcus viridans (SV) and culture negative (CN) IE frequency decreased over time (p<0.001), while enterococcal IE increased in the last decade (p<0.01). Patient age and male predominance increased over time as well. In subgroup analysis, SA frequency increased in North America, but not the rest of the world. This was due, in part, to an increase in intravenous drug abuse IE in North America (p<0.001). Among population-based studies (n=18; 3,477 patients) no significant changes were found.

Conclusion: Important changes occurred in IE epidemiology over the last half-century, especially in the last decade. Staphylococcal and enterococcal IE percentage increased while SV and CN IE decreased. Moreover, mean age at diagnosis increased together with male:female ratio. These changes should be considered at the time of decision-making in treatment of and prophylaxis for IE.

Figure 1. Flowchart of the selection process.

Figure 2. Epidemiology of Infective Endocarditis.

Figure shows age (A), male percentage (B) or prosthetic valve IE (C) of patients in each decade (mean in green, centerline of diamond) and variance (as size of diamond) plus standard deviation (blue). Each dot in column represents a particular study mean. N below decades represents total number of patients in each decade. A) IE patients are older in the last two decades. B) Male to female ration increased in the last decade. C) No significant changes were found on prosthetic valve IE. However a trend towards an increase can be seen. *= p<0.05; **=p<0.01; ***=p<0.001.

Figure 3. Summary of Worldwide Microbiology of Infective Endocarditis.

Bars represent percentage of Staphylococcus aureus (SA) (light green), Streptococcus viridans (SV, dark green), enterococci (Entero, light blue), coagulase-negative staphylococcus (CNS, dark blue), and Culture negative (CN, white) endocarditis in each decade. *= p<0.05; **=p<0.01; ***=p<0.001.

Figure 4. Microbiology of Infective Endocarditis.

Figure shows percentage of Staphylococcus aureus (SA) IE (A), coagulase-negative staphylococcus (CNS, B), enterococci (C), Culture negative (D) and Streptococcus viridans (SV, E) of patients in each decade (mean in green, centerline of diamond) and variance (as size of diamond) plus standard deviation (blue). Each dot in column represents a particular study mean. N below decades represents total number of patients in each decade. A) SA increased in the last decade. B) CNS increased over time. C) enteroccoci increased in the last decade. D) Culture negative endocarditis decreased in the last decade. E) SV decreased over time. *= p<0.05; **=p<0.01; ***=p<0.001.

Figure 5. Regional Differences for Staphylococcus Aureus and Intravenous Drug Abuse.

Figure shows percentage of Staphylococcus aureus (Staph, SA) IE in North America (A) or Europe (B) and intravenous drug abuse related IE in North America (C) and Europe (D), of patients in each decade (mean in green, centerline of diamond) and variance (as size of diamond) plus standard deviation (blue). N below decades represents total number of patients in each decade. A) SA increased markedly over last half century in North America B) No changes in SA were found in Europe. C) IVDA related IE frequency increased in North America. D) IVDA related IE percentage decreased in Europe in the last decade. *= p<0.05; **=p<0.01; ***=p<0.001.

Figure 6. In-Hospital Mortality of Infectious Endocarditis.

Figure shows percentage of in-hospital mortality of Infectious Endocarditis in each decade (mean in green, centerline of diamond) and variance (as size of diamond) plus standard deviation (blue). Each dot in column represents a particular study mean. N below decades represents total number of patients in each decade. In-hospital mortality decreased after the 1960s and remained stable thereafter. ∗∗=p<0.01.