ORLANDO — A standard 7-week course of enhanced external counterpulsation therapy in patients with heart failure who are on optimal pharmacotherapy improves their exercise duration, quality of life, and New York Heart Association class for at least 6 months afterward, according to the results of a randomized trial presented at the annual meeting of the American College of Cardiology.
“We believe these results suggest that EECP provides adjunctive therapy in patients with New York Heart Association [NYHA] class II-III heart failure receiving optimal pharmacologic therapy,” said Arthur M. Feldman, M.D., chairman of the steering committee for the Prospective Evaluation of EECP in Congestive Heart failure (PEECH) trial.
PEECH involved 187 patients with systolic heart failure (HF) and a mean ejection fraction of 26% who were randomized at 29 medical centers to optimal drug therapy alone or in combination with 35 hour-long EECP sessions over 7 weeks.
Patients were unblinded as to their treatment allocation, as were their treating physicians; however, a separate group of blinded investigators performed all patient evaluations, explained Dr. Feldman, professor and chairman of the department of medicine at Thomas Jefferson University, Philadelphia.
The primary study end point was at least a 60-second improvement in exercise duration at follow-up 6 months after the last EECP session. This was achieved in 35% of the EECP group and 25% of controls, a significant difference.
However, there was no between-group difference in a predefined alternative primary end point, the percentage of patients achieving at least a 1.25-mL/kg per minute increase in peak oxygen consumption (VO2).
Exercise duration improved by a mean of 25 seconds in the EECP group, whereas it declined by 10 seconds among controls. To put this 35-second difference into perspective, Dr. Feldman said randomized trials of cardiac resynchronization therapy show it typically results in roughly a 50-second differential in exercise duration, compared with sham therapy.
Improvement in NYHA class was a secondary PEECH end point. At 6 months, 31% of the EECP group, and only 14% of controls showed at least a one-class improvement.
Another secondary end point was quality of life as measured in terms of change from baseline in scores on the Minnesota Living with HF questionnaire.
One month after completion of the EECP sessions, treated patients had a mean 8.9-point improvement, compared with a 3.4-point gain in controls. The quality of life advantage favoring the EECP group remained significant at 3 months, but not at 6 months.
EECP was well tolerated, although one patient developed a pulmonary embolism that investigators believed was therapy related.
Discussant Andrew D. Michaels, M.D., characterized the PEECH results as “mixed.”
“The trial met one of two primary end points. It's somewhat concerning that the end points that were met—namely increased exercise duration, improved quality of life, and improvement in [NYHA] class—are all subject to the placebo effect,” added Dr. Michaels of the University of California, San Francisco.
Dr. Feldman said that although EECP resulted in a significant gain in VO2 in an earlier pilot study, the PEECH population may have been biased against realizing a similar benefit because they were predominantly NYHA class II and hence didn't have a long way to go to reach an essentially normal response.
EECP utilizes a series of ECG-synchronized inflatable cuffs wrapped around the legs. The cuffs swiftly inflate at onset of diastole and rapidly deflate at onset of systole, providing hemodynamic effects similar to intraaortic balloon counterpulsation, including increased coronary artery blood flow along with afterload reduction.
EECP is approved for the treatment of stable angina and the average physician payment under Medicare is $138.34 per session.
Both Dr. Feldman and Dr. Michaels are consultants to Vasomedical Inc., which markets EECP systems and sponsored the PEECH trial.