Most heart failure cases are discovered after patients admitted to hospital

About three out of four people diagnosed at a hospital with congestive heart failure were admitted for some other health condition, a new study found.

This finding surprised the researchers and may have significant implications for patient outcomes, medical costs and care.

People with secondary CHF – those who were admitted to the hospital for another reason – were more likely to die than were those diagnosed with primary CHF, incurred more medical costs and spent more time in the hospital.

The study included a year's worth of inpatient records from more than 2.5 million people admitted to 350 hospitals in the United States . More than half a million of these patients were diagnosed with CHF.

“We expected to see some patients with secondary congestive heart failure, but we didn't think that the vast majority of congestive heart-failure cases would fall into that category,” said Joseph Dasta, a study co-author and a professor of pharmacy at Ohio State University .

Congestive heart failure is a serious condition in which the heart doesn't pump blood as efficiently as it should, leading to a buildup of fluids in body tissues.

Dasta and his colleagues presented their findings in May in Washington , D.C. , at the American Heart Association's Sixth Scientific Forum on Quality of Care and Outcomes Research in Cardiovascular Disease and Stroke.

The researchers used a healthcare database that contained information on patients admitted to 350 hospitals in the United States in 2003. They wanted to know what resources were used to treat people with CHF as well as the costs affiliated with treating those patients.

Of the 2.5 million people admitted to the hospitals that year, one in five (20 percent, or 498,713) had a CHF diagnosis. Of those, 73.7 percent (367,656) were diagnosed with secondary CHF.

And the differences in treatment costs and outcomes between the two groups – primary vs. secondary CHF – are quite significant, said Amy Durtschi, a study co-author and a clinical assistant professor of pharmacy at Ohio State .

On average, people with a diagnosis of secondary CHF stayed in the hospital about three days longer (9.5 days vs. 6.4 days) and their total hospital costs were about $6,000 higher ($20,084 vs. $14,395.)

These patients were twice as likely to die during their hospital stay – 8 percent of the people with secondary CHF died, compared to 4.3 percent of the people with primary CHF. Also, the people diagnosed with secondary CHF were more likely to be discharged to a skilled nursing facility, rather than being sent home.

The researchers say they aren't sure why three-quarters of heart failure patients are diagnosed with secondary heart failure. But they speculate that it may have to do with the difficulty of diagnosing heart failure along with other diseases which are seen in heart failure patients, coupled with the business and economic issues related to coding and hospital outcomes.

For example, if a person is admitted to a hospital twice in one month because of CHF, most insurance companies won't pay for a second diagnosis of primary CHF in that same month, Durtschi said.

“So a physician may need to look for another problem as the primary reason to admit the patient,” she said. “Granted, if someone experiences congestive heart failure twice in one month, he probably has other health problems, too.”

Dasta and Durtschi plan to take a deeper look at the differences between primary and secondary CHF. For one, they'd like to know if CHF combined with any kind of diagnosis – regardless of whether CHF is primary or secondary – drives up hospital and patient costs.

The researchers received financial support from Abbott Laboratories, Abbott Park, Ill. Abbott Laboratories paid for the services performed by NDC Health, the company that owns the database the researchers used.