Benefits of On-X Mitral Valve Replacement in Cases of Infective Endocarditis.

Purpose. Mitral valve replacement (MVR) is necessary in cases of severe infective endocarditis (IE). Because the On-X valve is expected to be effective in reducing prosthesis-associated turbulent blood flow, we investigated the hemodynamic efficacy of the On-X valve when used for MVR in cases of mitral valve IE. Methods. We compared postoperative outcomes between two groups of patients who underwent MVR for IE: 13 given an On-X valve and 27 given an SJM valve. Results. There were no in-hospital deaths. Late death occurred in 6 cases, all in the SJM group (P = 0.1520). The incidence of late postoperative atrial fibrillation was relatively low in the On-X group (1 case vs. 10 cases, P = 0.068). Univariate analysis showed an association between the effective orifice area and postoperative atrial fibrillation. The effective orifice area and indexed effective orifice area were significantly larger in the On-X group at 2.8 ± 0.7 cm² vs. 2.2 ± 0.5 cm² (P = 0.007) and 1.8 ± 0.5 cm²/m² vs. 1.4 ± 0.4 cm² (P = 0.003), respectively. Conclusions. The suggested reduction in left atrial load attributed to the use of the On-X valve in MVR for IE may reduce the incidence of postoperative atrial fibrillation. [ABSTRACT FROM AUTHOR]