Patient–valve mismatch: A comparison of mechanical versus biological prostheses in ischemic mitral patients undergoing chordal-sparing mitral valve replacement

BackgroundChordal-sparing mitral valve replacement (MVR) is now preferred over downsized annuloplasty repair in treating chronic severe ischemic mitral regurgitation. However, total leaflet preservation carries the risk of patient–valve mismatch (PVM). The authors aimed to investigate the incidence of PVM among those groups of patients who were treated with either mechanical or biological MVR.ObjectiveThis study aimed to compare the incidence of PVM in ischemic mitral regurgitation patients undergoing total revascularization together with chordal-sparing MVR with either biological or mechanical prosthesis.Patients and methodsA controlled prospective study was carried out at the National Heart Institute Cairo, Egypt. 50 patients who underwent total revascularization together with chordal-sparing MVR for chronic severe ischemic mitral regurgitation were studied to determine the incidence of postoperative PVM. A total of 25 patients had received a biological mitral valve, while the other 25 patients had received a mechanical valve; postoperatively, the authors calculated the pressure gradients across the mitral valve of both groups and the effective orifice area that was indexed to the body surface area of the patients. PVM was defined as an indexed effective orifice area of less than or equal to 1.2 cm2/m2.ResultsThe mean age was 66.32 ± 3.33 years in the biological group and 59.68 ± 2.92 years in the mechanical group. There were nine female patients (36%) in the biological group and seven female patients (28%) in the mechanical group. Aortic cross-clamp time was longer in the biological group, 134.4 ± 8.44 min, with a P value of less than 0.001. ICU stay was longer in the biological group 110.4 ± 21.82 h, with a P value of 0.035. The indexed effective orifice area showed no significant difference between the two groups. There was a tendency for freedom from PVM in the mechanical group, but this did not reach a significant level (P = 0.057).ConclusionMechanical valves are less likely to induce PVM in ischemic mitral patients undergoing chordal-sparing MVR.