New research from Columbia University Medical Center is challenging the traditional explanation for the causes of the most common type of heart failure, traditionally called diastolic heart failure.
The study of 145 patients at NewYork-Presbyterian Hospital/The Allen Pavilion suggests that the most common type of heart failure is caused by health problems outside the heart.
The study, published in the April issue of the Journal of Cardiac Failure, suggests the majority of heart failure cases might be better treated with drugs to target specific disorders that are causing the heart failure - e.g. anemia, obesity, hypertension and diabetes - rather than the treatments currently prescribed specifically for heart failure.
Heart failure is the currently the number one reason for hospital admission in patients over the age of 65. With the growing elderly population this condition is expected to increase exponentially. Current estimates are that of the more than 5 million people in the United States with heart failure, more than half have heart failure despite the heart having normal pumping function.
"Our data suggests that the classic definition of heart failure fails to take into account the wide range of health problems that can be associated with the disease," said Mathew S. Maurer, M.D., Irving Assistant Professor of Medicine at Columbia University College of Physicians and Surgeons and Director of the Clinical Cardiovascular Research Laboratory for the Elderly at the NewYork Presbyterian Hospital/The Allen Pavilion, who was the study's principal investigator. "A broader view of heart failure is necessary to understand its causes and treat these patients."
Heart failure patients have been routinely classified into one of two groups - those with hearts that are pumping abnormally, considered systolic heart failure, and those with hearts that pump blood out normally but have trouble filling with blood, which was typically called diastolic heart failure.
The patients who were the subject of the study have heart failure but normal ejection fractions – the measurement of the heart's ability to pump blood. It was previously believed that heart failure patients with a normal ejection fraction had small, thick-walled hearts that made it exceedingly difficult for them to fill with enough blood. The Columbia study showed, however, that many patients with heart failure and normal ejection fractions had hearts that were bigger than average.
Previous studies failed to account for the shape of the heart, but a one-of-a-kind three-dimensional imaging system developed by Columbia University Medical Center's Donald King, professor emeritus of radiology, provided an accurate measurement of heart shape. The other studies just measured heart width, but Dr. King's 3-D echocardiography system also measured heart length, proving that these patients did not have smaller hearts, as previously believed.