Thursday, November 11, 2004

ESCAPE: Using PAC for acute heart failure treatment is safe but doesn't change outcomes
By Julie McKeel

A randomized evaluation of patients hospitalized with heart failure has concluded that pulmonary artery catheter (PAC)-monitored treatment is just as safe as treatment based on clinical signs alone. However, PAC-guided treatment doesn't improve clinical outcomes, reported investigators from the Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness (ESCAPE) this week at the 2004 American Heart Association Scientific Sessions.

Dr. Monica Shah, formerly with DCRI and now with Columbia University, presented the results along with Lynne Stevenson, MD, of Brigham and Women’s Hospital in Boston. ESCAPE was a multicenter trial designed to test the long-term safety and effectiveness of treatment guided by PAC monitoring and clinical assessments versus that guided by clinical assessments alone in patients hospitalized with severe heart failure.

Recent studies have raised concern that PAC-monitored treatment is widely used with not much evidence that it helps clinically and some indications that it may hurt. However, nonrandomized studies suggest that PAC improves symptoms of heart failure and quality of life and decreases hospitalizations.

Lynne Stevenson, MD

The ESCAPE trial studied 433 patients with recurrent severe heart failure at 26 U.S. and Canadian sites. These patients were assigned to PAC treatment plus clinical assessment or clinical assessment alone. The patients were ill enough so that use of PAC was considered feasible but also stable enough so that urgent PAC was not required for management.

The goal for both study groups was to reduce congestion and improve both lung and heart capacities. The primary end point of ESCAPE was the number of days that patients were hospitalized or dead during the 6 months after randomization. Secondary end points were changes in blood flow through the heart, peak oxygen consumption, and levels of natriuretic peptides, which are proteins produced by the heart in response to overwork. Other secondary end points included PAC-associated complications, resource use, distance walked in 6 minutes, and survival adjusted for patient preferences.

The use of PAC did not significantly affect the primary endpoint or the endpoints of time to death, death plus hospitalization, or days hospitalized. PAC-associated complications occurred in 9 patients randomized to PAC and 1 patient randomized to clinical assessment alone (P =0.01), with no PAC-related deaths occurring. Exercise improved in both groups with the PAC group showing slightly greater improvement.

The ESCAPE trial also explored an often-overlooked aspect of medicine: how the patient's goals for therapy may differ from the clinician's. Quality of life endpoints were measured using the Minnesota Living with Heart Failure questionnaire, which asks the question, "If you had 24 months to live in your current state of health, how many months would you trade to feel better?"

"At the beginning," said Stevenson, "the average patient was willing to trade nine months away. We found this astounding. At the same time we are designing trials to test survival, the patients are saying that what matters to them most was not to live longer, but to live better."

According to Stevenson, patients who had been managed with the PAC were willing to trade fewer months, "wanting six months more time in their current state of health than before treatment, compared with only 1.5 months of improvement in the other group."

"This trial teaches us some important lessons about what patients want. We call survival a hard end point because we can count who dies. The paradox is that survival was not the major goal for most patients in the trial."

Monica Shah, MD

ESCAPE was sponsored by the National Heart, Lung, and Blood Institute. The DCRI project leader for ESCAPE was Cynthia Binanay, and Bruce Althoff, Nevia Hayes, Jane Shavender, Gudaye Tasissa, and Wanda Tate and Drs. Rob Califf, Vic Hasselblad, and Chris O’Connor also were involved with the study.