New research raises the possibility that lifesaving AIDS (news – web sites) drugs may also increase the risk of heart trouble, though experts say the medicines’ benefits still far outweigh any hazard.
Researchers are at odds over whether the drug combinations are bad for the heart. Conflicting studies of the question were released in Seattle at the Ninth Annual Retrovirus Conference, which concluded Thursday.
The drug combinations have been in widespread use for about six years and have prevented thousands of AIDS deaths. However, doctors are still learning about possible long-term effects.
Some of these side effects quickly became apparent, including odd rearrangements of body fat and a variety of metabolic abnormalities, such as changes in cholesterol levels. But it was unclear whether these would eventually lead to extra heart trouble.
Some of the strongest evidence of a possible heart risk comes from a large study conducted by the Centers for Disease Control and Prevention (news – web sites). It suggests that the overall risk is low, because most patients are relatively young. Nevertheless, those on the drugs have about five times the usual risk of heart attacks.
But another study of U.S. veterans found no such increase.
“It’s not possible to say which is right,” said Dr. Harold Jaffe, the CDC’s acting AIDS chief. “The question is important and will get much more attention in the coming years.”
People with AIDS often take three or more medicines, including a category of drugs called protease inhibitors that are a key ingredient of the pill combinations.
Dr. Scott Holmberg and others from the CDC followed the health of 5,676 HIV (news – web sites)-infected people in eight cities from 1993 to 2001. Half took protease inhibitors.
Heart attacks were rare. Nevertheless, there were 13 among those getting protease inhibitors, compared with just two among people who did not take the medicines.
Protease inhibitors influence the body’s ability to regulate sugar and fat levels in the blood, and there is some evidence of an overall increase in heart attacks among people being treated.
“For all those reasons, we think we are seeing an early but still relative small problem,” Holmberg said.
However, a study led by Dr. Samuel Bozette of the University of California at San Diego questioned whether patients have actually had more heart problems since the introduction of the drug combinations with protease inhibitors.
He examined records of 36,766 HIV-infected veterans over the same period as the CDC’s review. There were about 1,800 hospital admissions for heart disease and strokes.
He concluded that if anything, there was a slight decline in heart disease and strokes following the introduction of protease inhibitors.
“Drug use is going up tremendously. Survival is going up tremendously. But this complication does not seem to be changing,” said Bozette, whose study was partially financed by drug makers.
A smaller analysis by doctors from the Kaiser Permanente health plan in Oakland, Calif., also found no increase in heart trouble among HIV-infected patients after the introduction of protease inhibitors. However, they found heart disease was almost twice as common among people with HIV than in those without, and they concluded that the virus itself, rather the treatment, might be the explanation.
Holmberg said doctors should be especially careful to make sure that people on AIDS treatments lower their risk of heart disease by quitting smoking, keeping their blood pressure under control and taking cholesterol-lowering drugs, if necessary.
“As people with HIV live longer, we will see more of these diseases of aging, so we need to worry more about just keeping people alive,” he said.