肺动脉导管临床试验的混杂结果

一项叫做ESCAPE的大规模临床试验发现：死亡与使用肺动脉导管并不相关、入院治疗并不增加，但是提示肺动脉导管不应当做为常规来指导治疗。

肺动脉导管是一种很薄的导管，插入颈静脉穿过右侧心腔进入肺动脉，测量来自右侧心腔流和肺组织的压力与血流。使用一个微小充气气囊测量来自左侧心腔的压力。有3％～5％住院治疗的心衰患者使用肺动脉导管。医生还使用肺动脉导管为每一个患者进行个体化药物治疗，测量药物对心脏功能和症状的作用。

ESCAPE试验包括26个地区的433例患者。初始目标是评估肺动脉导管测量心脏和肺压力精确度的提高，与其它基于对生理体征与症状临床评估的治疗方法相比较，是否能够提高患者生存率以及在6个月内减少住院时间。

Brigham and Women医院的首席研究员Lynne Stevenson博士质问说：“我们知道接受肺动脉导管的患者感觉好了许多，但是为什么他们的死亡与住院治疗并不减少？” Stevenson医生相信，隐藏于事实后面的答案是：用于治疗患者的肺动脉导管的资料存在巨大差异。研究人员正在对临床试验中的超声心动图资料进行深度分析，这或许能够提供调整治疗方法的手段，而无需冒肺动脉导管的风险。
 
Mixed Results in PAC Trial
 
The results of a large clinical trial called ESCAPE (Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness) revealed no deaths related to the use of a pulmonary artery catheter (PAC) and no increase in hospitalizations but did suggest that a PAC should not be routinely used to guide therapy.

A PAC is a thin catheter inserted into a neck vein and passed through the right side of the heart into a pulmonary artery in order to measure pressures and flows from the right side of the heart and the lungs. A tiny balloon is inflated to allow the measurement of pressures from the left side of the heart. A PAC is used in 3-5% of heart-failure patients who are hospitalized. Doctors also use a PAC to individualize medications for each patient and gauge their effects on heart function and symptoms.

ESCAPE involved 433 patients at 26 sites. The primary goal was to evaluate whether the increased precision offered by a PAC regarding heart and lung pressures results in improved patient survival and reduced time spent in the hospital over six months, compared with other therapies based on clinical assessment of physical signs and symptoms.

“We know that patients who received a PAC felt better, but then why didn’t they have fewer deaths or hospitalizations?” asked principal investigator Dr. Lynne Stevenson, of Brigham and Women’s Hospital (Boston, MA, USA). Dr. Stevenson believes the answer may lie in the fact that there was a big variation in how PAC information was used to treat patients. The researchers are conducting an in-depth analysis of the echocardiogram data in the trial, which may suggest some ways to adjust therapy without the risks of a PAC.