SURGICAL MANAGEMENT OF ACTIVE INFECTIVE ENDOCARDITIS DURING 1996-06 IN TABRIZ, NORTHWESTERN IRAN

Objective: Surgical treatment of active infective endocarditis (IE) requires not only homodynamic repair, but also, special emphasis on the eradiation of the infection to prevent recurrence. This study was undertaken to examine the outcome of surgery for active infective endocarditis in a cohort of patients.
Patients and Methods: One hundred and sixty-four consecutive patients underwent valve surgery for active IE in Madani heart centre (Tabriz, Iran) from 1996 to 2006. The patients with diagnosis of IE (according to Duke Criteria) were eligible for the study.
Results: The mean age of patients was 36.3 ± 16 years, with 34.6±17.5 yrs for native valve endocarditis and 38.6±15.2 yrs for prosthetic valve endocarditis (p= 0.169). Ninety-one (55.5%) of patients were males. The infected valve was native in 112 (68.3%) of patients and prosthetic in 52 (31.7%). There was no predisposing heart disease in 61 (37%) of patients. The aortic valve was infected in 78(47.6%), the mitral valve in 69 (42.1%), and multiple valves in 17 (10.3%) of patients. Active culture-positive endocarditis was present in 81 (49.4%) whereas 83(50.6%) patients had culture-negative endocarditis. Staphylococcus aureus was the most common isolated microorganism. Ninety patients (54.8%) were in NYHA classes III and IV. Mechanical valves were implanted in 69 patients (42.1%) and bioprostheses in 95 (57.9%), including homograft in 19 (11.5%) cases. There were 16 (9%) operation-related deaths, but only 1 death in patients undergoing aortic homograft replacement. Reoperation was required in 18 (10.9%) cases.
Based on multivariate logistic regression analysis, Staphylococcus aureus infection (p= 0.008), prosthetic valve endocarditis (p=0.01), paravalvular abscess (p=0.001) and left ventricular ejection fraction less than 40% (p=0.04) were independent predictors of hospital mortality.
Conclusions: Surgery for infective endocarditis continues to be challenging and associated with high operation-related mortality and morbidity. Prosthetic valve endocarditis, impaired ventricular function, paravalvular abscess and Staphylococcus aureus infection associated with hospital mortality. Also we found that aortic valve replacement with an aortic homograft could be performed with acceptable hospital mortality and provided satisfactory results.