Background In patients with ischemic mitral regurgitation requiring mitral valve replacement (MVR), the choice of the prosthesis type is crucial. The exercise hemodynamic and functional capacity performance in patients with contemporary prostheses have never been investigated. To compare exercise hemodynamic and functional capacity between biological (MVRb) and mechanical (MVRm) prostheses.

Methods and Results We analyzed 86 consecutive patients with ischemic mitral regurgitation who underwent MVRb (n=41) or MVRm (n=45) and coronary artery bypass grafting. All patients underwent preoperative resting echocardiography and 6-minute walking test. At follow-up, exercise stress echocardiography was performed, and the 6-minute walking test was repeated. Resting and exercise indexed effective orifice areas of MVRm were larger when compared with MVRb (resting: 1.30±0.2 versus 1.19±0.3 cm²/m²; P=0.03; exercise: 1.57±0.2 versus 1.18±0.3 cm²/m²; P=0.0001). The MVRm had lower exercise systolic pulmonary arterial pressure at follow-up compared with MVRb (41±5 versus 59±7 mm Hg; P=0.0001). Six-minute walking test distance was improved in the MVRm (pre-operative: 242±43, post-operative: 290±50 m; P=0.001), whereas it remained similar in the MVRb (pre-operative: 250±40, post-operative: 220±44 m; P=0.13). In multivariable analysis, type of prosthesis, exercise indexed effective orifice area, and systolic pulmonary arterial pressure were joint predictors of change in 6-minute walking test (ie, difference between baseline and follow-up).

Conclusions In patients with ischemic mitral regurgitation, bioprostheses are associated with worse hemodynamic performance and reduced functional capacity, when compared with MVRm. Randomized studies with longer follow-up including quality of life and survival data are required to confirm these results.

背景在需要二尖瓣置换术 (MVR) 的缺血性二尖瓣关闭不全患者中，假体类型的选择至关重要。从未研究过当代假肢患者的运动血流动力学和功能能力表现。比较生物（MVRb）和机械（MVRm）假肢的运动血流动力学和功能能力。

方法和结果我们分析了 86 名连续接受 MVRb (n=41) 或 MVRm (n=45) 和冠状动脉旁路移植术的缺血性二尖瓣关闭不全患者。所有患者均接受术前静息超声心动图检查和6分钟步行试验。随访时进行运动负荷超声心动图检查，并重复进行 6 分钟步行试验。与 MVRb 相比，MVRm 的静息和运动指数有效孔面积更大（静息：1.30±0.2 vs 1.19±0.3 cm ² /m ²；P = 0.03；运动：1.57±0.2 vs 1.18±0.3 cm ² /m ²；磷=0.0001)。与 MVRb 相比，MVRm 在随访时具有较低的运动收缩肺动脉压（41±5 对 59±7 mm Hg；P = 0.0001）。MVRm 的 6 分钟步行测试距离有所改善（术前：242±43，术后：290±50 m；P = 0.001），而 MVRb 保持相似（术前：250±40，术后：220±44 m；P = 0.13）。在多变量分析中，假体类型、运动指数有效孔面积和收缩期肺动脉压是 6 分钟步行试验中变化的联合预测因子（即基线和随访之间的差异）。

结论与 MVRm 相比，在缺血性二尖瓣关闭不全患者中，生物假体与更差的血流动力学表现和降低的功能能力有关。需要进行更长随访的随机研究，包括生活质量和生存数据来确认这些结果。