June 5, 2006
CONTACT: Susanne Hartman
Penn Researchers Conclude the ‘Gold
Standard’ in Assessing the Course of Treatment
“Heart failure cardiologists utilize this special kind of exercise test, which examines your body’s ability to utilize oxygen during maximal exercise, to determine a course of treatment for our patients. Up until now, there has been one absolute cut-off level, based on VO2 stress test results, for both men and women. It’s been the ‘gold standard’ for us to decide the risk of proceeding with a treatment like transplant, ventricular assist devices or other therapies,” said Mariell Jessup, MD, Medical Director of the Heart Failure and Transplant program and Professor of Medicine at Penn.
The VO2 is an exercise test in which a patient walks on a treadmill. The patient is outfitted with a mouthpiece that measures the amount of oxygen the body is using during exercise. It can determine how well the heart muscle is delivering oxygen to the muscles of the body in order to do work. If the heart muscle is weak, and the body tries to exercise, the heart may not be able to keep up with the stressful demand and deliver enough oxygen rich blood to muscles. The test measures a patient’s ability to function (their functional capacity to live and work).
Based on the prognosis, it helps to guide cardiologists in deciding which advanced treatments may have to be considered for their patients. If patients have a result below the standard cut-off level, the cardiologist may consider a heart transplant or ventricular assist device.
“The physician must consider the risk of the therapy versus the
risk of keeping what the patient already has. Of all the things we do,
the maximal VO2 is the most potent predictor. We decided to look at what
happened to these patients, both men and women, after they had the VO2
stress test done, to see how many of them went on to receive a heart transplant
and how many did not survive,” explains Lee Goldberg, MD,
MPH, an investigator in the study and Associate Director of the
Heart Failure and Transplant program at Penn. “There have been other
studies suggesting the outcome for women with heart failure is better
than men. We took that one step further, and for the first time, went
back to investigate the outcomes of male and female patients based on
what their VO2 stress test result had been. Now, the question is –
if the VO2 is the main determinant for prognosis in heart failure, we
need to make sure we’re using the right cut-off for both genders.”
The investigators caution that while we now know there are gender differences to consider in determining treatment in heart failure patients, and that this is an important observation -- there is much more research that remains to be done in this area.
The results of this study are published in the June 6, 2006 issue of the “Journal of the American College of Cardiology.” You can access the journal on-line at: http://content.onlinejacc.org/current.dtl. The article is titled, “Effects of Gender on Peak Oxygen Consumption and the Timing of Cardiac Transplantation.” The principal investigator of this study and senior author is Andrew Kao, MD, FACC. Other investigators include Sammy Elmariah, MD and Michael Allen, EMT-P.
This was a single site study conducted at Penn. There was no external funding for this study.
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