Prevalence of extracardiac vascular complications in Abiotrophia spp. and Granulicatella spp. infective endocarditis: Two case reports and a systematic review

Objectives: Infective endocarditis (IE) caused by Abiotrophia spp. and Granulicatella spp. share an increased risk of extracardiac vascular complications (EVC). The current work aims to assess the prevalence of EVC in IE due to these microorganisms. Methods: This was a study with mixed design, consisting in a single center experience combined with a systematic review of multiple databases. We included studies enrolling adults >18 years old with a diagnosis of Abiotrophia spp. and Granulicatella spp. IE. We collected data regarding the presence and the description of EVC in IE along with clinical and microbiological details. Risk of bias assessment was performed using the Newcastle-Ottawa Scale for comparative observational studies, and a dedicated tool for single-arm non-comparative studies. The review was registered in PROSPERO (CRD42023433130). Results: The cohort study identified 2 patients. The systematic review included 83 studies, involving 228 cases of Abiotrophia spp. (n = 103), Granulicatella spp. (n = 94), and unspecified nutritionally variant streptococci (n = 31) IE. EVC occurred in 101/230 (44 %) patients, central nervous system involvement occurred in 66/101 (66 % of total embolisms), and pseudoaneurysm or peripheral vascular embolization occurred in 11/101 (11 %). Conclusions: Considering the observed prevalence of EVC a proactive approach in the diagnosis of such a complication is warranted.