Enterococcal Endocarditis: Prospective Data from the Iranian Registry of Infective Endocarditis

Enterococci are responsible for 5% to 18% of infective endocarditis (IE) cases. We aimed to determine demographic data, predisposing factors, clinical presentations, complications and echocardiographic findings concerning enterococcal endocarditis.

Since 2006, all adult patients with a possible or definite diagnosis of IE based on the modified Duke criteria have been enrolled in the Iranian Registry of Infective Endocarditis. In this study, patients with IE of enterococcal origin were detected and their demographic characteristics, predisposing factors, complications, laboratory data and echocardiographic findings were assessed.

Out of 731 patients diagnosed with endocarditis. Enterococci were found in 60 patients: 32 men (53.3%) and 28 women (46.7%) at a mean age of 55.21 ± 17.9 years. Definite IE was diagnosed in 57 (95%) patients, and possible IE was suspected in 3 patients (5%). The most frequent predisposing factor was the prosthetic valve (n=28, 46.7%), followed by a history of previous endocarditis (n=12, 20%). An acute course (<6 wk) was reported in 38 patients (63.3%). Fever (n=58, 95%) and loss of appetite (n=17, 28.3%) were the most frequent symptoms. The most frequent location of involvement was the aortic valve (n=22, 36.7%), followed by the mitral valve (n=20,33.3%). Vegetation was detected in 53 patients (88.3%), abscess formation in 8 (13%). Fifteen patients (25%) had heart failure, and 11 (18%) had central nervous system complications. The mortality rate was 20%.

Given the serious complications and the high mortality rate in the patients with IE of enterococcal origin, which may be due to these organisms' intrinsic resistance to many antibiotics, we suggest further studies to determine more effective antibiotic regimens and even individualized antibiotic therapies for enterococcal endocarditis.