徐迎佳，硕士，副主任医师。新加坡进修三年。主要从事心内科常见病、多发病的诊治，尤其是冠心病的综合治疗，且在心内科重症的处理方面积累了丰富的经验。 Dr. Xu Yingjia   Associate Consultant of Department of Cardiology，Shanghai Chest Hospital，Shanghai, PRC

新一代左室辅助装置在非终末期心衰患者中的应用前景   New Generation LVADs Destined for Less Sick HF Patients   （上海市胸科医院 徐迎佳 翻译）   要点：装置的微型化简化了手术过程，降低了并发症的发生率。   新一代左室辅助装置的安全性能有了明显的提高，研究者试图将其应用于非终末期心衰的患者，以延长这部分患者的长期生存率，这是心衰器械治疗专题会带给我们的信息。   HeartWare公司研发的植入心包腔内的新一代左室辅助装置HVAD，为一微型的离心泵，可产生动力推动10L/min的血流量。它利用被动式磁轴承和水力轴承的共同作用使无磨损的血泵转子悬浮并旋转起来，产生离心力，推动血液流动。   来自华盛顿医院的Boyce医生汇报了这一新型装置的最新临床试验结果。试验的一级终点定为180天生存率或心脏移植。目前入选了45名患者，其中89%的患者生存期超过180天，其平均依赖HVAD的天数为253天。五名患者在HVAD的支持下仍发生死亡，而另三名患者则成功地脱机。这组患者使用了新一代的左室辅助装置后血液动力学、心功能分级和生活质量都有了明显的改善。   来自费城的Acker医生主要报道了Ventracor公司生产的名为“VentrAssist"的左室辅助装置。这是第三代的左室辅助装置，为一生物相容的离心泵，通过血液动力学机制使血泵转子悬浮并旋转。它被植入左侧横膈下的囊袋。   Acker医生提到了2001年的REMATCH研究，这是第一代左室辅助装置应用于终末期心衰患者的前瞻性研究。研究结果提示LVAD组的早期生存率为药物治疗组的2倍，但二年后两组的生存率无差异。这一研究结果一经公布，随后的研究定位于重症心衰患者应用LVAD效果不劣于药物治疗，对此，Acker医生认为，现在我们迫切地需要REMATCH II研究的出台。   Acker医生进一步指出，LVAD的研究结果不尽如人意，其中很重要的原因是这组患者病情太重，全身营养状况和各器官功能均衰退，如果这群患者有机会早些植入LVAD，最终的结果将有很大的不同。   事实上，Ventracor公司已开始进行一项临床研究，涉及病情相对较轻的心衰患者，患者随机分为二组，一组为短期应用VentrAssist（不超过48小时）和药物治疗，一组为单纯药物治疗。一级终点为无中风的生存，死亡和优于药物治疗，目前已入选了14例患者。   路易斯维尔大学的Dowling博士提出部分辅助装置能补偿2-3L/min的心输出量，扩大了应用指征，可使更多的患者获益。更值得一提的是，整个装置可置于皮下，避免了胸骨切开和转流带来的风险。 在计算机模型研究中，这一装置能有效地提高体循环的灌注，在一比较部分辅助和完全辅助的研究中，接受部分辅助的患者在峰值氧耗和活动耐量等参数方面明显占优势。   Dowling博士着重谈了CircuLite公司的Synergy口袋式循环辅助装置，它类似于起搏器的大小，可通过微创胸廓手术植入。在欧洲有关这一装置的实验性研究已经启动，入选了13例患者，植入后，平均动脉压和心输出指数有了明显的提高。其中8名患者已成功接受了心脏移植， 两名患者在装置的支持下情况稳定，其中一名已经使用装置长达213天。   使用辅助装置的一大缺点是血栓发生率高，一旦发生需更换装置。Dowling博士的报告中提到自使用新一代的Synergy装置后，迄今尚没有发生血栓的报道。   总的来讲，Dowling博士认为部分辅助装置，不仅改善了心衰的生化指标，而且对靶器官的功能、血液动力学和活动耐量均有很大帮助。   （来源：www.tctmd.com）   New Generation LVADs Destined for Less Sick HF Patients   Key Points: Miniaturized devices avoid risks of major surgery.   By TCT Daily Staff   As left ventricular assist devices have evolved and become safer, researchers have looked toward implanting them in less sick patients, offering the possibility of longer-term survival, according to presenters at a session devoted to device-based approaches to heart failure.   One example of a new generation LVAD is HeartWare’s intrapericardial HVAD. This miniaturized centrifugal pump is capable of generating up to 10 L/min of flow. Its wearless impeller is suspended in the pump housing through a combination of passive magnets and hydrodynamic thrust bearing.   Stephen W. Boyce, MD (right), of the Washington Hospital Center in Washington, D.C., provided an update of a pivotal trial of patients implanted with the device. The primary endpoint is survival to 180 days or transplantation. With 45 patients enrolled so far, 89% have survived at least 180 days, with an average time on support of 253 days.   Five patients have died while on support, while three have recovered. According to Boyce, patients have experienced significant improvements in hemodynamics, functional class activity levels, and quality of life. Michael A. Acker, MD, of the University of Pennsylvania Health System in Philadelphia, Penn., focused on the VentrAssist LVAD from Ventracor. This third-generation device is a centrifugal biocompatible pump with a hemodynamically suspended impeller. It is implanted in the left sub-diaphragmatic pocket on bypass.   Awaiting a REMATCH   For perspective, Acker referred to the 2001 REMATCH trial involving first-generation LVADs in end-stage heart failure patients. Early survival of patients on LVADs was doubled compared to those on medical therapy, but the benefit disappeared after two years. Since that time, the field has been stuck doing noninferiority trials in very sick patients, Acker indicated. "We need a ‘REMATCH II’ and we need it desperately," he said.   The VAD field has struggled to overcome a Catch-22, said Acker: The reason LVAD results are not better is that only patients with "one foot in the grave" are referred, but that when LVAD results improve, less sick patients will be referred. But, Acker argued, poor results have been driven not by technology failures but by the fact that patients are referred too late, after their nutritional status and end-organ function have declined. "If we could operate on these patients earlier, our results would be better," he noted.   In fact, Ventracor has initiated a destination therapy trial that includes an arm of less sick patients who are not in immediate need of an LVAD. They are randomized to VentrAssist within 48 hours plus medical therapy or medical management alone. The primary endpoint in this arm is survival without stroke or death and superiority to medical therapy. This trial arm has enrolled 14 patients to date.   Employing partial assist devices   Robert D. Dowling, MD, of the University of Louisville, Kentucky, suggested that one way to expand the patient population that may benefit is to employ partial assist devices, which supplement native cardiac output with 2-3 L/min of flow. These smaller devices can be placed superficially, without the risk associated with bypass and sternotomy.   In computer modeling, the devices improved systemic perfusion, and in a trial comparing partial and full support, patients who received partial assist devices did significantly better in parameters such as peak oxygen consumption and ability to exercise.   Dowling singled out the Synergy Pocket Circulatory Assist device. It is small enough to be placed in a pacemaker-like pocket with a mini-thoracotomy approach. The device’s maker, CircuLite, has initiated a pilot study in Europe that so far has enrolled 13 patients. After implantation, the mean arterial pressure and cardiac index increased markedly. Eight patients have been successfully transplanted. Two are still doing well on support; one has been on the device for 213 days.   One downside has been the need for pump exchange due to thrombosis. But since a newer Synergy model has been implanted there have been no instances of thrombosis, Dowling said.   In conclusion, Dowling said, partial assist devices improve not only surrogate markers of heart failure but end-organ function, hemodynamics, and functional status.   Disclosures: Dr. Boyce reports owning stock in HeartWare. Dr. Acker reports no relevant conflicts of interest. Dr. Dowling reports receiving consulting fees from CircuLite.   （source：www.tctmd.com）