Clinical Characteristics and Risk Factors for in-Hospital Mortality in 240 Cases of Infective Endocarditis in a Tertiary Hospital in China: A Retrospective Study

Purpose: This study aimed (i) to investigate the clinical characteristics and risk factors related to in-hospital mortality in patients with infective endocarditis (IE) and (ii) to compare the differences in three age groups. Methods: A total of 240 IE cases diagnosed using the modified Duke criteria between January 2016 and December 2019 were included and retrospectively studied. Patients were stratified into three age groups: < 50 y, 50-65 y, and > 65 y. Results: The mean age of the patients was 51 +/- 14 y, and 154 patients (64.2%) were male. In addition, 136 (56.7%) patients with IE had no previous cardiac disease. Congenital heart disease (CHD, 21.3%) was the most common underlying heart disease, followed by rheumatic heart disease (RHD, 8.8%). Streptococcus was found in 55 (22.9%) patients and was the most common causative pathogen, comprising 52.9% of all positive blood cultures. Echocardiography showed the presence of vegetations in 88.3% of cases and the predominant involvement of the left heart valves. Fever and cardiac murmur were the most frequent presentations, with no significant differences among age groups. Compared with younger patients, elderly patients had a lower operation rate and higher in-hospital mortality. The independent risk factors of in-hospital mortality were age > 65 y, intracranial infection, splenic embolization, cerebral hemorrhage, NYHA class III-IV, and prosthetic valve infection. Conclusion: CHD replaces RHD as the most common underlying heart disease in IE patients. Patients without previous cardiac disease are at increased risk of IE. Streptococcus is still the primary causative pathogen of IE. Elderly patients present with more comorbidities and complications, in addition to a more severe prognosis than younger patients. Age older than 65 y, intracranial infection, splenic embolization, cerebral hemorrhage, NYHA class III-IV, and prosthetic valve infection showed poorer in-hospital outcomes.