Columbia Researchers Develop New Method For Diagnosing Form Of Heart Failure
New York, NY – July 15, 2002 – Researchers at Columbia University have developed a measurement that may solve the problem of diagnosing diastolic heart failure, a form of the disease in which the heart continues to pump normally but has trouble relaxing. Heart failure, a disease due to heart pumping problems, affects more than 5 million Americans. Standard heart failure diagnosis relies on assessing the ejection fraction, a measure of how much blood the heart pumps vs. how much blood the heart holds. An abnormal heart pumps out less than half the heart's blood volume with each beat and has an ejection fraction of 45 percent or lower. This type of heart failure is termed systolic, where the contraction or pumping of the heart, especially the ventricles, is abnormal. But more than 2.5 million people with heart failure symptoms have diastolic heart failure, a condition where the heart still ejects more than 55 percent of its blood and has a normal ejection fraction but holds less blood than a healthy heart. Yet no diagnostic test exists to confirm the problem.identify their problem.
Now Columbia investigators led by Dr. Mathew Maurer, Warner Lambert Assistant Professor of Medicine at Columbia University and director of the Clinical Cardiovascular Research Laboratory at the Allen Pavilion of NewYork-Presbyterian Hospital, have developed a new, non-invasive way to confirm diastolic heart failure. Dr. Maurer et al. are publishing their findings from a study of 140 people using the method, called myocardial contraction fraction, in the July 17 Journal of the American College of Cardiology.
“Diastolic hHeart failure, characterized by shortness of breath, fatigue, persistent coughing, and/or fluid accumulation that may cause swelling of the feet, ankles, legs, and abdomen, is predominantly associated with aging and the long term effect of hypertension and diabetes,” Dr. Maurer says. “As continues to increase in prevalence and incidence because people arpeople aree living longer and suffering the effects of these conditions, due to higher rates of hypertension and diabetesdiastolic heart failure continues to increase at alarming rates. Researchers have long been interested in studying diastolic heart failure but have not had an objective test that would help them confirm the diagnosis.do so. We feel strongly that this may be the test.”
The myocardial contraction fraction relies on a 3-D echocardiograph, developed at Columbia by Dr. Donald King, professor emeritus of radiology and first author of the study. The 3-D echocardiograph takes a series of cross-sectional pictures or “slices” that allow researchers to reconstruct a clear and concise image of the whole heart. In the study, Lyna El-Khoury Coffin, manager of the Clinical Cardiovascular Research Laboratory and a highly experienced cardiac sonographer, performed and analyzed each reconstruction. The researchers used the reconstructed image to compare the amount of blood the heart pumps with the amount of heart muscle mass. Standard ejection fraction uses a two-dimensional echocardiograph and does not measure muscle mass.
In the study, Columbia researchers measured ejection fractions and myocardial contraction fractions in three groups of 140 adults: physically fit, normal sedentary, and adults with diastolic heart failure. All three groups had normal ejection fractions, but their myocardial contraction fractions showed drastic differences – physically fit averaged 50 percent, normal sedentary averaged 40 percent, and diastolic heart failure patients averaged 30 percent.
“Ejection fraction does not identify diastolic heart failure patients because their hearts continue to pump more than half the amount of blood the heart holds,” Dr. Maurer says. “By comparing how much blood the heart pumps with how much heart muscle is pumping the blood, we found that patients with diastolic heart failure had a reduction in the myocardial contraction fraction (MCF). The MCF was also higher in young athletic subjects compared to sedentary normals and was the only variable that we studied which adequately distinguished these subjects.
“The ability of the myocardial contraction fraction to distinguish these groups of patients may be because it quantifies how the heart works in concert with the blood vessels,” Dr. Maurer says. “Our hope is that this will drive the field forward and lead to further research and treatment for diastolic heart failure patients.”