P2754Streptococcal infective endocarditis: distribution of species and their prognosis

Abstract

Abstract Background Infective endocarditis (IE) is frequently caused by streptococcal species. However, there is limited knowledge about the relationship between different streptococcal species and IE, and their associated outcomes. Purpose To examine the prevalence of streptococci at species level in IE, and to relate these different species to outcomes. Methods From 2002–2012 we prospectively collected consecutive patients with IE admitted to two tertiary heart centres covering a catchment area of 2.4 million people. The registry comprises 915 IE patients, 366 (40%) with streptococcal IE. Based on phylogenetic relationship, streptococcal species were classified into seven main groups: Mitis, Bovis, Mutans, Anginosus, Salivarius, Pyogenic and Nutritionally Variant Streptococcus (NVS). Classification at species level was not possible in 51 patients, who were excluded. Complications and prognosis of streptococcal IE were compared between the subgroups, and at species level. Results We included 315 patients with streptococcal IE. Mean age was 63 (IQR 52–76) years, and most were men (67%). A total of 115 patients (37%) had a previous heart valve disease, 58 (18%) had a prosthetic valve, 22 (7%) had previously had IE and 29 (9%) had a cardiac electronic device. With 148 episodes (47%) the Mitis group was the most common cause of IE. Other frequent groups were the Pyogenic group and the Bovis group, accounting for 66 (21%) and 51 (16%) of the cases, respectively. Surgery was carried out in 55% (n=173) of all cases. Patients infected with S. pneumoniae or S. agalactiae had a significantly higher rate of surgery, 72.2% (n=13) and 71.9% (n=23) respectively, whereas the Bovis group had a significantly lower rate, 35.5% (n=18) (p=0.048). The aortic valve was infected in 137 patients (43.5%), mitral valve in 105 patients (33.3%) and both valves were infected in 53 patients (16.8%). Twenty patients (6.3%) had right-sided IE, including pacemaker lead IE. There was no significant difference between the species subgroups regarding type of infected valve. Embolization and osteitis were observed in 76 (24.1%) and 30 (9.5%) patients, respectively. There was no significant difference between the species groups, as was the case with mortality: 23 patients (7.3%) died in-hospital and the one-year mortality was 16% (n=50). Distribution of streptococcal IE Conclusion Species of the Mitis group were the most frequent Streptococci causing IE. Patients infected with S. pneumonia or S. agalactiae had significantly higher rate of surgery, and patients infected with S. bovis group had lower rate of surgery. There was no significant difference in rate of complications such as abscesses, embolization, osteitis or mortality between the streptococcal species. Acknowledgement/Funding Supported by grants from Herlev-Gentofte University Hospital Research Foundation