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.