Influence of the Severity of Infective Endocarditis on Long-Term Outcomes After Mitral Valve Surgery

Previous studies have demonstrated the advantages of mitral valve repair (MVP) in infective endocarditis (IE) in early and late outcomes. However, the influence of complexity in mitral valve surgery on long-term outcome is unclear. The purpose of this study was to clarify whether the severity of IE affects long-term outcome.

Fifty-one patients who underwent mitral valve surgery during the active phase of native IE were retrospectively reviewed. Severity score was used as an index for the severity of IE. Severity score assigns a score derived from two aspects: (1) the extent of valvular destruction and (2) technical difficulties for predicting the feasibility of MVP reported by our previous studies. Patient profile, long-term survival, and freedom from recurrence of mitral regurgitation (MR) were compared between those with a severity score of 7 or less (low score: n = 17) and with a severity score of 8 or more (high score: n = 34). Recurrence of MR was defined as a more than moderate grade of MR.

Body weight was lower and body surface area was smaller in high score, and concomitant aortic valve operation was more frequently performed in high score than in low score. MVP was more frequently performed in low score than in high score (88% vs. 38%, P < 0.001), and patients in low score showed a better 10-year survival rate than those in high score (100% vs. 70%; log-rank, P = 0.020). Freedom from recurrence of MR in 10 years after MVP was 100% vs. 53% in low score and high score, respectively (P = 0.008).

Severity of IE is associated with long-term outcome. Patients with low severity have high feasibility of MVP, low risks of reoperation, and good long-term survival. In patients with high severity, the indication for complex repair should be considered, taking age and future redo surgery into consideration.