Additionally, the researchers found that patients with the more common, but less severe, form of the disease consume similar amounts of health care resources.
These findings are important, said Lawrence Liao, M.D., Duke cardiologist and principal investigator of the Duke studies, because heart failure is the only cardiovascular disease whose incidence is increasing in the U.S. Given the aging of the population, Liao said that national policy makers need concrete data in deciding how to allocate scarce health care resources - both for treatment and further research.
Liao presented the results of the Duke analysis today (Nov. 12, 2003) at the 76th annual scientific session of the American Heart Association (AHA). His research into this issue was supported by an AHA grant.
"This is the first study to determine the long-term inpatient and outpatient costs of heart failure in an elderly population," Liao said. "Even after accounting for their worse survival and greater co-morbid illness, these patients consume substantially more health care resources than patients without heart failure, and these higher costs persisted through four years of follow-up."
Heart failure is a condition marked by the inability of the heart muscles to pump enough oxygen and nutrients in the blood to the body's tissues. Also known as congestive heart failure, it has many causes, including infections of the heart, coronary artery disease, high blood pressure, previous heart attacks and valve problems. It is estimated that 4.7 million Americans suffer from the condition, with 400,000 new cases reported each year. Once diagnosed with heart failure, about 50 percent of patients will die within five years.
For his analysis, Liao consulted the National Heart Lung Blood Institute's Cardiovascular Health Study, which gathered detailed clinical data on 4,489 elderly Americans living in four regions: Forsyth County, N.C., Sacramento County, Calif., Allegheny County, Penn., and Washington County, Md. By correlating this data with Medicare claims, Liao was able to determine the economic impact of heart failure.
Patients without heart failure had an average of $3,962 of health care costs after one year, with $15,216 after four years. After four years, they had on average 0.92 hospitalizations and 27.9 outpatient doctor visits.
Of the 4,489 patients, 329 patients had heart failure at the beginning of the study, with average one-year costs of $9,545 and average four-year costs of $27,822. Additionally, 319 patients developed heart failure during the study, with one-year costs of $20,619 and four-year costs of $43,385.
"It makes sense for the newly diagnosed patients to have higher costs, since they tend to have more inpatient visits early in the acute phase of their disease," Liao said. "Those already with the disease tend to be cared for on an outpatient basis, which can be less costly."
Those with existing heart failure had on average 2.47 hospital visits after four years, compared to 3.41 for those who developed the disease during the study. In terms of outpatient visits, those with existing heart failure had an average of 34.8, compared to an average of 28.6 for those who developed the disease during the study.
There are two types of heart failure. The most widely known form, called systolic heart failure, is characterized by the inability of the heart to contract strongly enough. In a more newly recognized form of the disorder, known as diastolic heart failure, the heart beats normally but does not fill with enough blood. In both cases, the body is deprived of oxygen-rich blood.
Systole is that part of the heart's pumping cycle when it contracts and pushes blood out to the body. The diastole is when the heart relaxes and fills with blood in preparation for the next heart beat.
Diastolic heart failure has not been considered as serious as the systolic form because its mortality rate is about half that of systolic heart failure's 15 percent annual rate. However, it is estimated that in the elderly, diastolic heart failure is more prevalent than systolic heart failure.
After four years, patients with existing systolic heart failure had average costs of $24,349, compared to $29,162 for those with diastolic heart failure. In terms of patients who developed the disease during the study, systolic heart failure patients saws average costs of $38,303, compared to $44,623 for those who developed diastolic heart failure.
"There are many clinical trials that have examined systolic heart failure, while the number of trials looking at diastolic heart is minuscule," Liao said. "These data would suggest that in terms of its costs to the health care system, more studies need to be conducted to better understand diastolic heart failure."
Joining Liao in his analysis were, from Duke, James Jollis, M.D., David Whellan, M.D., Anita Chen, Kevin Anstrom, Ph.D., and Kevin Schulman, M.D. Also part of the team were D. Kitzman, M.D, Wake Forest University School of Medicine, Winston-Salem, N.C.; Gerard Aurigemma, M.D., University of Massachusetts Medical Center, Worcester, Mass.; and John Gottdiener, M.D., St. Francis Hospital, Roslyn, N.Y.