Mitral Valve Surgery in Patients with Isolated Mitral Valve Endocarditis - Analyzation of Perioperative Parameters and Long-Term Outcomes

Background: Aim of this study was to investigate the perioperative conditions as well as short- and mid-term outcome of patients with isolated mitral valve (MV) endocarditis undergoing MV surgery.

Methods: Between January 2002 and April 2013, a total of 264 patients with isolated MV endocarditis underwent MV surgery at the Leipzig Heart Center - 166 patients (72.9%) with median sternotomy and 98 patients (37.1%) minimally invasive through a right anterolateral minithoracotomy. Mean age was 63.3 ± 13,6 years, mean LVEF 49.4 ± 24.8%, 152 patients (57.6%) were male, 90 patients (34.1%) suffered from diabetes mellitus. Prior cardiac surgery was performed in 67 patients (25.4%), in average 5.5 ± 8.4 years before. Average logEuroSCORE was 27.7 ± 23.6%.

Results: Microbiological investigations of blood cultures and intraoperative material of the MV tissue/ vegetations were available in 205 patients (77.7%), were in 197 patients (96.1%) positive and showed as the reason for MV endocarditis staphylococcus aureus in 75 patients (38.1%), enterococcus faecalis in 16 patients (8.1%) and staphylococcus epidermidis in another 13 patients (6.6%). Vegetations were located in 37 patients (14%) on the posterior, in 84 patients (31.8) on the anterior, and in 135 patients (51.1%) on both leaflets of the MV. Preoperative cerebral emboli were observed in 21 patients (7.9%), splenectomy due to emboli was performed in 20 patients (7.6%). MV-replacement was performed in 231 patients (87.5%), MV repair with annuloplasty in 28 patients (10.6%), in 5 patients (1.9%) MV surgery was performed on the leaflet level (e.g., vegetatectomy). Overall 30-day mortality was 17.4%. Binary logistic regression analysis showed an increased 30-day mortality for patients with age = > 70 years (OR 2.5, p = 0.008, CI 95% 1.3–5.1), for patients with diabetes mellitus (OR 3.0, p = 0.002, CI 95% 1.5–6.0) and for patients with preoperative dialysis (OR 5.8, p = 0.004, CI 95% 1.8–19.2) Five years survival was 55.5% (95% CI 5.6–6.9 years). The freedom from MV-related reoperation due to reendocarditis after 5 years was 96.6% (95% CI 10.2–10.8 years).

Conclusions: Peri- and postoperative mortality risk for patients with MV surgery due to MV endocarditis is high, especially for patients with immunosuppression due to diabetes mellitus, preoperative dialysis and age > 70 years.