Fritzsche Dirk, Eitz Thomas, Laczkovics Axel, Liebold Andreas, Knaut Michael, Matschke Klaus, Sagie Alex, Mehlhorn Uwe, Horstkotte Dieter, Koerfer Reiner
Heart and Diabetes Center North Rhine-Westphalia, Bad Oeynhausen, Germany.
Ann Thorac Surg. 2007 Feb;83(2):542-8. doi: 10.1016/j.athoracsur.2006.07.074.
After heart valve replacement, patients are at risk of complications that are linked to irregular oral anticoagulation therapy. Depending on the type and position of the valve, the complication rate is 3% to 6% per patient-year. This study presents clinical results of a device enabling early detection of prosthetic dysfunction by frequency measurements.
Between November 2003 and March 2006, ThromboCheck devices were handed out to 483 patients after mechanical heart valve replacement from six heart centers. In each case, the devices were calibrated for individual patients early postoperatively. Taking control measurements, the device calculated deviations from calibrated frequency and amplitude ranges using a fast Fourier transform and sent a warning message to the display if any relevant changes occurred. This message was taken as cause to determine morphologic correlations of the disturbance using imaging techniques, for example, echocardiography or fluoroscopy (observation period, 550.7 patient-years; median application period, 15.1 months).
Twenty-five true positive, 1 false positive, and no false negative measurements occurred. Eleven patients (44%) received thrombolytic therapy with streptokinase or recombinant tissue-type plasminogen activator, resulting in normalization of the digital frequency analysis. In 4 patients (16%), international normalized ratio levels were adjusted under temporary heparinization therapy. Normalization of the valve sounds were achieved within 3 to 7 days. Seven patients (28%) required reoperation despite lysis therapy. Sensitivity was 100% during the observation period; specificity was 99.8%.
Digital frequency analysis represents a reasonable addition to the monitoring of patients after artificial heart valve replacement to detect prosthesis-related complications early on.
心脏瓣膜置换术后，患者存在与口服抗凝治疗不规律相关的并发症风险。根据瓣膜的类型和位置，每位患者每年的并发症发生率为3%至6%。本研究展示了一种通过频率测量能够早期检测人工瓣膜功能障碍的设备的临床结果。
在2003年11月至2006年3月期间，将血栓检查设备分发给来自六个心脏中心的483例接受机械心脏瓣膜置换术的患者。在每种情况下，术后早期对设备进行个体校准。通过对照测量，该设备使用快速傅里叶变换计算与校准频率和幅度范围的偏差，如果发生任何相关变化，会向显示屏发送警告信息。该信息被视为使用成像技术（例如超声心动图或荧光透视）确定干扰形态学相关性的依据（观察期为550.7患者年；中位应用期为15.1个月）。
出现25例假阳性、1例假阳性和无假阴性测量结果。11例患者（44%）接受了链激酶或重组组织型纤溶酶原激活剂的溶栓治疗，数字频率分析恢复正常。4例患者（16%）在临时肝素化治疗下调整了国际标准化比值水平。瓣膜声音在3至7天内恢复正常。7例患者（28%）尽管接受了溶栓治疗仍需要再次手术。观察期内敏感性为100%；特异性为99.8%。
数字频率分析是人工心脏瓣膜置换术后患者监测的合理补充，可早期检测与假体相关的并发症。
