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.