Comparison Between Healthcare-Associated and Community-Acquired Infective Endocarditis at Tertiary Care Hospitals in Japan

Background: Healthcare-associated infective endocarditis (HAIE) has become increasingly recognized worldwide because the underlying patient conditions are completely different from those of community-acquired infective endocarditis (CIE). However, data on HAIE in the Japanese population is lacking. We sought to clarify the patient characteristics and prognosis of HAIE in a Japanese population. Methods and Results: A retrospective study was conducted in 158 patients who were diagnosed with infective endocarditis, 53 of whom (33.5%) were classified as HAIE. Compared with patients with CIE, those with HAIE were older (median age 72 vs. 61 years; P=0.0002) and received surgical treatment less frequently (41.5% vs. 62.9%; P=0.01). Regarding causative microorganisms, staphylococci, including methicillin-resistant pathogens, were more common in patients with HAIE (32.1% vs. 14.3%; P=0.01). Patients with HAIE had higher in-hospital mortality (32.1% vs. 4.8%; P<0.0001) and Kaplan-Meier analysis showed worse prognosis for patients with HAIE than CIE (P<0.0001, log-rank test). On multivariate Cox analysis, HAIE (hazard ratio 3.26; 95% confidence interval 1.49-7.14), age >= 60 years, surgical treatment, stroke, and heart failure were independently associated with mortality. Conclusions: HAIE has different clinical characteristics and causative microorganisms, as well as worse prognosis, than CIE. Preventive strategies, and the prompt and appropriate identification of HAIE may improve the outcome of infective endocarditis.