Aortic root abscess and secondary infective mitral valve disease: results of surgical endocarditis treatment

Abstract

Mortality in active infective endocarditis (AIE) is substantial and reinfection can strongly influence outcome. Assessment of factors influencing mortality is important. We studied 108 (33%) patients suffering from root abscess out of a total of 327 AIE patients admitted to the Deutsches Herzzentrum Berlin for surgical treatment between 1996 and 2003. Among them were 53 (25.5% of all patients) who were diagnosed as having secondary infective mitral valve disease (SMVD). Mean age was 53+/-14.2 years; there were 37 men and 16 women. Risk factors were assessed on the basis of clinical, hemodynamic, echocardiographic and surgical information. Mean follow-up was 325+/-251 days with complete echocardiographic examination performed in patients with double valve surgery. The differences between groups were analyzed using Student's t-test. Multivariate analysis for the whole group suffering from abscess was performed to identify independent factors influencing mortality. In 19 (35.8%) patients suffering from SMVD mitral valve reconstruction was undertaken and mitral valve replacement was performed in 34 (64.2%) patients. There were 27 patients treated with a Shelhigh prosthesis: 18 with double valve replacement (both Shelhigh) and nine with an aortic Shelhigh prosthesis and concomitant mitral valve reconstruction. Homografts were used in 17 patients, with mitral reconstruction in 10 and a stented mitral prosthesis in seven. In nine cases two stented valve prostheses were used. The calculated mean Doppler gradient for homografts and Shelhigh in aortic position was 12 (+/-5.7) and 15 (+/-4.6), respectively (NS). The following predisposing factors for mortality were assessed: severe damage of aortic annulus (OR 4.65, CI 1.22-17.1, P=0.0159); septic shock (OR 3.44, CI 0.85-13.9, P=0.07) and poor ejection fraction (<40%), and dilated LV. Excessive mortality reaching 29% was noted in patients suffering from AIE with aortic ring abscess and SMVD requiring double valve surgery. Double valve surgery with semi-stented Dacron-free valve prostheses is associated with a low rate of reinfection and good function of the implants. The most potent independent risk factors for death were septic shock and severe aortic root destruction.