Are blood and valve cultures predictive for long-term outcome following surgery for infective endocarditis?

Objective: To evaluate whether perioperative bacteria identification in blo od and/or in valve cultures can predict early and late outcome of surgery f or infective endocarditis, a retrospective study was performed, Methods: Be tween January 1978 and December 1998, 232 patients, 79 (34.1%) female and 1 53 (65.9%) male with mean age of 44.95 +/- 1.03 years (range 8-79) underwen t surgery for infective endocarditis on a native (162 cases) or prosthetic (70 cases) valve. Patients were divided into three groups according to the perioperative x of microbiological tests: Group A: patients with preoperati ve positive blood cultures (83 cases); Group B: patients with positive valv e cultures (35 cases); Group C: patients with negative blood and valve cult ures (114 cases). Categorical values were compared by chi(2) analysis, wher eas continuous data were compared by ANOVA and Bonferroni correction for po st hoc comparisons. Analysis of late survival and complications was perform ed with Kaplan-Meier and Log Rank test. Late mortality, reoperation, periva lvular leak, recurrence of infection were considered as treatment failure. All data were presented as mean +/- standard error. Results: Hospital morta lity was 10.8% (9/83) in Group A, 8.6% (3/35) in Group B, and 14.9% (17/114 ) in Group C (P = 0.52; not significant (NS)). Ten-year survival was 62.7 /- 8% in Group A, 43.9 +/- 19% in Group B and 62.7 +/- 7% in Group C (P = 0 .38; NS). Ten-year freedom from reoperation was 85.2 +/- 6% in Group A, 37. 9 +/- 20% in Group B and 80 +/- 6% in Group C (P = 0.0034). Ten-year freedo m from treatment failure was 56.3 +/- 8% in Group A, 31.6 +/- 16% in Group B and 55.3 +/- 7% in Group C (P = 0.46, NS). Conclusions: Positive blood an d tissue cultures are not predictive for hospital mortality and late treatm ent failure in patients with infective endocarditis. Positive valve culture s, a common finding in patients with staphylococcal endocarditis, are predi ctive for a higher risk of reoperation. (C) 2000 Elsevier Science B.V. All rights reserved.