Three Separate Clinical Entities of Infective Endocarditis—A Population-Based Study From Southern Finland 2013–2017

Abstract

Background Health care-associated infective endocarditis (HAIE) and intravenous drug use-related IE (IDUIE) have emerged as major groups in infective endocarditis (IE). We studied their role and clinical picture in population-based survey. Methods A population-based retrospective study including all adult patients diagnosed with definite or possible IE in Southern Finland in 2013-2017. IE episodes were classified according to the mode of acquisition into three groups: community-acquired IE (CAIE), HAIE and IDUIE. Results Total of 313 episodes arising from 291 patients were included. Incidence of IE was 6.48/100,000 person-years. CAIE accounted for 38%, HAIE 31% and IDUIE 31% of IE episodes. Patients in IDUIE group were younger, they had more frequently right-sided IE (56.7% vs 5.0%, P<0.001) IE and S. aureus as etiology (74.2% vs 17.6%, P<0.001) compared to CAIE group. In-hospital (15.1% vs 9.3%, P=0.200) and cumulate one-year case-fatality rates (18.5% vs 17.5%, P=0.855) were similar in CAIE and IDUIE. Patients with HAIE had more comorbidities, prosthetic valve involvement (29.9% vs 10.9%, P=0.001), enterococcal etiology (20.6% vs 5.9%, P=0.002) and higher in-hospital (27.8% vs 15.1%, P=0.024) and cumulative one-year case-fatality rate (43.3% vs 18.5%, P<0.001) than patients with CAIE. Staphylococcus aureus caused one-fifth of IE episodes in both groups. Conclusion Our study indicates that in areas where injection drug use is common IDUIE should be regarded as a major risk group for IE along with HAIE and not seen as part of CAIE. Three different risk groups, CAIE, HAIE and IDUIE, with variable characteristics and outcome should be recognized in IE.

Healthcare-associated infective endocarditis: source of infection and burden of previous healthcare exposure

“…This retrospective population-based study included all IE episodes which were diagnosed and treated in adult patients during the years 2013–2017 and who resided in the study area. 7 All episodes met the modified Duke criteria for possible or definite IE. 9 Detailed study protocol has been previously presented.…”

“… 9 Detailed study protocol has been previously presented. 7 Roughly 0.9 million adults resided in the study area, which consisted of six municipalities in Southern Finland. Acute care hospitals, three that belong to Helsinki University Hospital and two Helsinki city hospitals, are responsible for the treatment of severe infections, such as IE, in this area, and these hospitals were included in the study.…”

“…The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in blood cultures has been low, and hence, only 8% of all IE episodes caused by S. aureus have been MRSA. 7 …”

“…In our population-based study including all adult IE episodes diagnosed between the years 2013 and 2017 in Southern Finland, we found that one-third of all episodes and almost half of the episodes in patients who did not inject drugs were HAIE. 7 The incidence of HAIE was 2.0/100,000 person-years in adult population. In this paper, we studied further the patients with HAIE to determine the source of infection, the associated microbiology, the extent, and impact of prior healthcare contact and differences between nosocomial and non-nosocomial acquisition of HAIE in a population-based level.…”

“… 3 – 6 HAIE is associated with considerably worse prognosis compared to community-acquired IE. 4 – 7 HAIE constitutes one-fourth to one-third of all IE cases, and its incidence is increasing. 4 – 8 The increase is most likely attributable to aging of the population, increasing number of invasive diagnostic and therapeutic procedures, more common cardiac surgery, and widened diagnostic criteria for HAIE.…”