Division of Cardiovascular Diseases, Mayo Clinic, Jacksonville, FL, USA.
J Thromb Haemost. 2014 Dec;12(12):1966-74. doi: 10.1111/jth.12734. Epub 2014 Oct 17.
Mitral valve regurgitation is associated with an acquired hemostatic defect.
We sought to assess the prevalence and severity of acquired von Willebrand syndrome in patients with native valve mitral regurgitation (MR).
PATIENTS/METHODS: Fifty-three patients were prospectively observed with bleeding questionnaires and laboratory tests when undergoing an echocardiographic assessment of MR. In patients referred for mitral valve surgery, testing was repeated postoperatively.
Echocardiography identified 13 patients with mild MR, 14 with moderate MR, and 26 with severe MR. Among patients with mild, moderate or severe MR, loss of the highest molecular weight von Willebrand factor (VWF) multimers occurred in 8%, 64%, and 85%, respectively, median platelet function analyzer collagen ADP closure times (PFA-CADPs) were 84 s (interquartile range [IQR] 73-96 s), 156 s (IQR 104-181 s), and 190 s (IQR 157-279 s), respectively, and the ratios of VWF latex activity to antigen were 0.92 (IQR 0.83-0.97), 0.85 (IQR 0.76-0.89), and 0.79 (IQR 0.75-0.82), respectively (all P < 0.001). Nine patients reported clinically significant bleeding, and seven had intestinal angiodysplasia and transfusion-dependent gastrointestinal bleeding (Heyde syndrome), with the median number of transfusions required being 20 (IQR 10-33; range 4-50). In patients who underwent mitral valve repair (n = 13) or replacement (n = 7), all measures of VWF function reported above improved significantly.
The high-shear environment of moderate to severe MR is sufficient to produce prevalent perturbations in VWF activity. Acquired von Willebrand syndrome may occur in this setting, and appears to be reversible with mitral valve surgery.
二尖瓣反流与获得性止血缺陷有关。
我们旨在评估原发性二尖瓣反流（MR）患者获得性血管性血友病（von Willebrand 综合征）的患病率和严重程度。
患者/方法：53 例患者前瞻性观察了出血问卷和实验室检查，同时进行了 MR 的超声心动图评估。对于接受二尖瓣手术的患者，术后重复检查。
超声心动图确定 13 例患者为轻度 MR，14 例为中度 MR，26 例为重度 MR。在轻度、中度或重度 MR 患者中，最高分子量 von Willebrand 因子（VWF）多聚体缺失分别发生在 8%、64%和 85%，血小板功能分析仪胶原 ADP 闭合时间（PFA-CADP）中位数分别为 84 秒（四分位距 [IQR] 73-96 秒）、156 秒（IQR 104-181 秒）和 190 秒（IQR 157-279 秒），VWF 乳胶活性与抗原的比值分别为 0.92（IQR 0.83-0.97）、0.85（IQR 0.76-0.89）和 0.79（IQR 0.75-0.82）（均 P <0.001）。9 例患者报告有临床显著出血，7 例有肠道血管扩张和依赖输血的胃肠道出血（Heyde 综合征），中位数输血次数为 20（IQR 10-33；范围 4-50）。在接受二尖瓣修复（n = 13）或置换（n = 7）的患者中，上述所有 VWF 功能指标均显著改善。
中重度 MR 的高剪切环境足以引起 VWF 活性的普遍改变。获得性血管性血友病可能在此情况下发生，并且似乎可以通过二尖瓣手术逆转。
