Stevenson L W
Cardiovascular Division, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA.
Ann Thorac Surg. 1996 Jan;61(1):380-7; discussion 391-2. doi: 10.1016/0003-4975(95)00997-3.
Patients with advanced heart failure often cannot undergo cardiac transplantation soon enough to prevent fatal hemodynamic deterioration or sudden death. The approach to these patients includes tailoring of medical therapy with vasodilators and diuretics, which allows stabilization of 60% to 80% of potential candidates. Current criteria for mechanical support before transplantation currently focus on the identification of hospitalized patients with at least 30% chance of death before transplantation. The much larger question relates to the potential use of mechanical support to bridge ambulatory patients, who represent 90% to 95% of the transplant waiting list, with waiting times frequently exceeding 2 years.
From 1988 to 1993, 265 potential candidates were discharged after evaluation for transplantation with New York Heart Association class IV status and left ventricular ejection fraction of 0.25 or less. Patients were analyzed for clinical hemodynamic and echocardiographic profiles that would identify ambulatory patients unlikely to survive without urgent transplantation.
After tailored medical therapy, presenting hemodynamic parameters are not useful for predicting 2-year survival without urgent transplantation, which was 45% at 2 years. Left ventricular diastolic dimension of 80 mm or greater was associated with only 29% two-year survival without urgent transplantation. Serum sodium level less than 132 mEq/L predicted 35% two-year survival without urgent transplantation. Peak oxygen consumption less than 10 mL.kg-1.min-1 identified poor outcome but was often not measured in patients with resting symptoms.
Although definition of indications for urgent bridging requires complex clinical assessment based on immediate risk, it should be possible to identify a larger ambulatory population for whom improved devices will offer extended survival without transplantation.
晚期心力衰竭患者往往无法及时接受心脏移植以预防致命的血流动力学恶化或猝死。针对这些患者的治疗方法包括使用血管扩张剂和利尿剂进行个体化药物治疗，这可使60%至80%的潜在候选者病情稳定。目前移植前机械支持的标准主要集中于识别住院的、移植前死亡风险至少为30%的患者。而一个更大的问题是机械支持在门诊患者中的潜在应用，这些患者占移植等待名单的90%至95%，等待时间常常超过2年。
1988年至1993年，265名潜在候选者在因纽约心脏协会心功能IV级且左心室射血分数为0.25或更低而接受移植评估后出院。分析患者的临床血流动力学和超声心动图特征，以识别不进行紧急移植就不太可能存活的门诊患者。
经过个体化药物治疗后，初始血流动力学参数对预测不进行紧急移植的2年生存率并无帮助，2年生存率为45%。左心室舒张末期内径80mm或更大与不进行紧急移植的2年生存率仅29%相关。血清钠水平低于132mEq/L预测不进行紧急移植的2年生存率为35%。峰值耗氧量低于10mL·kg-1·min-1表明预后不良，但有静息症状的患者常常未进行此项测量。
尽管紧急过渡治疗适应证的定义需要基于即时风险进行复杂的临床评估，但应该能够识别出更多的门诊患者群体，对于他们而言，改进的设备将在不进行移植的情况下延长生存期。
