Clinical Features and Outcomes of Streptococcus anginosus Group Infective Endocarditis: A Multicenter Matched Cohort Study.

BACKGROUND: Although Streptococcus anginosus group (SAG) endocarditis is considered a severe disease associated with abscess formation and embolic events, there is limited evidence to support this assumption.

METHODS: We performed a retrospective analysis of prospectively collected data from consecutive patients with definite SAG endocarditis in 28 centers in Spain and Italy. A comparison between cases due to SAG endocarditis and viridans group streptococci (VGS) or Streptococcus gallolyticus group (SGG) was performed in a 1:2 matched analysis.

RESULTS: Of 5336 consecutive cases of definite endocarditis, 72 (1.4%) were due to SAG and matched with 144 cases due to VGS/SGG. SAG endocarditis was community acquired in 64 (88.9%) cases and affected aortic native valve in 29 (40.3%). When comparing SAG and VGS/SGG endocarditis, no significant differences were found in septic shock (8.3% vs 3.5%, P  = .116); valve disorder, including perforation (22.2% vs 18.1%, P  = .584), pseudoaneurysm (16.7% vs 8.3%, P  = .108), or prosthesis dehiscence (1.4% vs 6.3%, P  = .170); paravalvular complications, including abscess (25% vs 18.8%, P  = .264) and intracardiac fistula (5.6% vs 3.5%, P  = .485); heart failure (34.7% vs 38.9%, P  = .655); or embolic events (41.7% vs 32.6%, P  = .248). Indications for surgery (70.8% vs 70.8%; P  = 1) and mortality (13.9% vs 16.7%; P  = .741) were similar between groups.

CONCLUSIONS: SAG endocarditis is an infrequent but serious condition that presents a prognosis similar to that of VGS/SGG.