Frazier O H, Benedict C R, Radovancevic B, Bick R J, Capek P, Springer W E, Macris M P, Delgado R, Buja L M
Division of Cardiopulmonary Transplantation, Texas Heart Institute at St. Luke's Episcopal Hospital, Houston, USA.
Ann Thorac Surg. 1996 Sep;62(3):675-81; discussion 681-2. doi: 10.1016/s0003-4975(96)00437-7.
This study assessed the effect of prolonged left ventricular unloading on native ventricular function.
We reviewed data from 31 patients (30 men, 1 woman) supported more than 30 days (mean, 137 days; range, 31 to 505 days) with the HeartMate left ventricular assist system. The patients' mean age was 46 years (range, 22 to 64 years); 17 had idiopathic and 14 had ischemic cardiomyopathy. Data (anatomic, physiologic, hemodynamic, histologic, and biochemical) were collected at the time of HeartMate implantation, during support with the device temporarily off, and at the time of device explantation.
Routine chest roentgenogram showed improvement in cardiothoracic ratio (0.62 +/- 0.04 to 0.55 +/- 0.03; p < 0.0001). Echocardiography performed with the pump off showed a significant decrease in left ventricular end-diastolic dimension (6.81 +/- 0.87 cm to 5.39 +/- 1.08 cm; p < 0.0005) and a significant improvement in ejection fraction (0.11 +/- 0.05 to 0.22 +/- 0.17; p < 0.02). Cardiac index increased (1.96 +/- 0.52 L.min-1.m-2 to 2.93 +/- 0.73 L.min-1.m-2; p < 0.0001), mean aortic pressure increased (71.40 +/- 10.63 mm Hg to 76.33 +/- 16.84 mm Hg; p = 0.48), pulmonary capillary wedge pressure decreased (24.18 +/- 6.27 mm Hg to 14.48 +/- 3.01 mm Hg; p < 0.0001), and pulmonary vascular resistance decreased (3.34 +/- 2.00 Wood units to 2.51 +/- 0.88 Wood units; p < 0.05). Comparisons of tissue samples taken at the time of implantation and at the time of transplantation showed a marked reduction in myocytolysis. Calcium uptake, calcium-binding rates, and lipid levels normalized in patients studied. Plasma norepinephrine levels decreased to near normal levels.
Prospective studies are now indicated to determine whether device removal without transplantation may be beneficial in selected patients.
本研究评估了长期左心室卸载对天然心室功能的影响。
我们回顾了31例患者（30例男性，1例女性）的数据，这些患者使用HeartMate左心室辅助系统支持超过30天（平均137天；范围31至505天）。患者的平均年龄为46岁（范围22至64岁）；17例患有特发性心肌病，14例患有缺血性心肌病。在植入HeartMate时、设备暂时关闭支持期间以及设备取出时收集数据（解剖学、生理学、血流动力学、组织学和生物化学数据）。
常规胸部X线片显示心胸比率改善（从0.62±0.04降至0.55±0.03；p<0.0001）。在泵关闭状态下进行的超声心动图显示左心室舒张末期内径显著减小（从6.81±0.87 cm降至5.39±1.08 cm；p<0.0005），射血分数显著改善（从0.11±0.05升至0.22±0.17；p<0.02）。心脏指数增加（从1.96±0.52 L·min⁻¹·m⁻²升至2.93±0.73 L·min⁻¹·m⁻²；p<0.0001），平均主动脉压升高（从71.40±10.63 mmHg升至76.33±16.84 mmHg；p = 0.48），肺毛细血管楔压降低（从24.18±6.27 mmHg降至14.48±3.01 mmHg；p<0.0001），肺血管阻力降低（从3.34±2.00 Wood单位降至2.51±0.88 Wood单位；p<0.05）。对植入时和移植时采集的组织样本进行比较，结果显示肌细胞溶解明显减少。所研究患者的钙摄取、钙结合率和脂质水平恢复正常。血浆去甲肾上腺素水平降至接近正常水平。
现在需要进行前瞻性研究，以确定对于某些选定患者，不进行移植而移除设备是否有益。
