The changing epidemiology of infective endocarditis in a tertiary center


Despite the adequate antibiotic prophylaxis, the incidence and mortality rate of infective endocarditis (IE) is still high. In the past few decades, several studies have noted an increase in the proportion of IE caused by staphylococcal species.The aim of our retrospective study was to assess the clinical and microbiological characteristics, trends, and the 1, 6 and 12-month cardiovascular (CV) mortality rate of patients administered for IE in our tertiary hospital between January 1, 2006 and December 31, 2016.We identified 465 cases (311 men, 154 women) of 448 patients, mean age was 56,1 ± 16,4 years (14-92). Native left-sided IE (NLIE) was assessed in 286 cases (61,5%, mitral in 117, aorta in 116, combined in 53 cases), prosthetic valve IE (PVIE) was in 111 cases (24%, early in 44, late in 67), right-sided IE (RIE) in 12 cases (2,5%), cardiac device related IE (CDRIE) in 50 cases (11%), other in 6 cases (1%). The underlying infection was caused by streptococci in 124 cases (27%), Staphylococcus aureus (SA) in 112 cases (24%, out of them 23 had MRSA), coagulase negative Staphylococcus (CoNS) in 39 cases (8%), enterococci in 75 cases (16%). Blood culture negative cases found in 61 patients (13%), in 38 cases (8%) other, diversified germs and in 16 cases (4%) there were no data on the pathogen agent. one-month was 12.8%, six-month was 26.4%, one-year was 29.7%, and five-year was 40%. There was a significant difference in the mortality rate regarding both of the type of IE and in terms of the underlying microorganism (log-rank p = 0.03 and p = 0.04 resp). The worst survival rate was detected among patients with PVIE, and patients with staphylococcal infection, especially with MRSA. Cox regression found that age (HR: 1.4; CI:1.3-1.6; p <0.001), ejection fraction (HR: 1.4; CI:1.2-1.5; p <0.001), hemoglobin and creatinin levels (HR: 0.9; CI:0.8-0.97 p = 0.01; HR: 1.3; CI: 1.1-1.5; p = 0.001 resp.), MRSA compared to streptococcal infection (HR: 2.5; CI:1.4-4.5; p <0.001), stroke as complication (HR: 1.98; CI:1.4-2.8; p <0.001) were independent risk factors of mortality.In terms of temporal trends the rate of combined NLIE decreased over time (14.5% to 5.1%, p = 0.03), while the rate of other types of IE did not changed. Regarding the type of underlying microorganism the rate of SA infection increased (17% to 41%, p = 0.002) and the rate of CoNS decreased (16.1% - 1.3% p < 0.001) over time. The 1-year mortality rate did not change through the years.During the observed 11 years 465 cases were administered with IE to our tertiary hospital, out of which two-third were NLIE. One-quarter of the underlying microorganism were streptococci, and the rate of Staphylococcus aureus infection was increased over time, which was associated with a worse prognosis. In addition IE had a high mortality, which unfortunately did not improve through the years.