NEW YORK - Though fewer American adults were hospitalized with heart failure during the last decade, hospitalization rates among heart failure patients under age 55 saw the least change, according to a new study.
Based on billing data for almost 1.7 million US heart failure patients, researchers found that the number of hospital stays for the condition fell overall by about 27 per cent between 2001 and 2009.
"There have been significant reductions in the absolute number of heart failure hospitalizations. It's just the speed is not the same among the younger patients," said Dr. Jersey Chen, the study's lead author from Kaiser Permanente's Mid-Atlantic Permanente Research Institute in Rockville, Maryland.
Previous research has shown that the number of hospital stays for heart failure - when the heart cannot pump enough blood to the body - dropped by nearly a third between 1998 and 2008 for patients covered by Medicare, the government insurance programme for people over 65.
But the causes of heart failure often differ between younger and older patients, Chen and his colleagues write in the Journal of the American College of Cardiology, and they were unsure whether there had been a comparable drop in hospital stays among younger patients.
For the new study, the researchers used a database of billing records for Americans 18 years old and older.
Between 2001 and 2009, hospitalizations for heart failure fell from 633 hospital stays per 100,000 people to 463 stays per 100,000.
Adults 65 years old and older saw the greatest reductions in hospital stays - a drop of about 37 per cent over the nine years. That compared to a decrease of just 13 per cent among patients 18 to 44 years old and 16 per cent among those between 45 and 55.
The researchers also found that younger heart failure patients showed little reduction in how long they spent in the hospital, or how many of them died within 30 days of admission.
Length of stay in the hospital, on average, fell from about 5.6 days in 2001 to 5.3 days in 2009. But the change was almost entirely among patients over age 65.
Deaths within 30 days of entering the hospital fell by about 8 per cent among adults younger than 45 over the nine-year period, compared to a drop of 22 per cent for patients 45 to 54 years old and a drop of 36 per cent for patients between 55 and 64.
Chen told Reuters Health "the jury is still out" on why younger patients haven't seen the same reductions in heart failure hospitalizations and deaths in the hospital, but it's an area of active research.
He told Reuters Health that it could be that management of risk factors for heart failure in older adults - such as high blood pressure and heart disease - is easier to control, compared to the typical causes of the condition in younger patients.
Birth defects in the heart, for example, would be harder to avoid than high blood pressure, he said.
"I think we need to figure out why, what is causing the heart failure in the younger patients, more precisely than what we can get from this administrative data," Chen added.
The differences between older and younger heart failure patients may also be explained by differences in hospital care and insurance, noted Dr. Adrian Hernandez, an associate professor of medicine and cardiology at the Duke University School of Medicine in Durham, North Carolina.
"While (the authors) speculate some of this may be greater risk factor control, that doesn't seem like something that would have much impact on length of stay," said Hernandez, who wasn't involved in the new research.
Hernandez told Reuters Health there could be differences between a younger patient and an older adult in what an insurer is willing to pay for.
"(The findings are) good news for certain patient groups that have been able to get out of the hospital faster and on a better course, but there is more work to be done to make sure all patients have that experience," Hernandez said.