SAN FRANCISCO, Sept. 30 (UPI) -- Elderly people with mild to moderate kidney disease who have a heart attack are less likely to get some common life-saving therapies than are heart attack victims without kidney disease, a new study reported Monday.
People age 65 and older who had reduced kidney function and did get treatments such as aspirin, beta blockers or angiotensin converting enzyme -- ACE inhibitors -- were about twice as likely to survive the first 30 days after a heart attack compared to kidney patients who did not receive such interventions.
Lead researcher Michael G. Shlipak told United Press International, "Historically, the use of certain medications, particularly ACE inhibitors and aspirin, has been feared in patients with kidney disease."
Shlipak, assistant professor of medicine at University of California and a physician-investigator at the Veterans Administration Medical Center, both in San Francisco, said there is some basis for this fear, as these patients have a greater risk for side effects.
"However, studies have shown that treatment of patients with kidney disease with these medications will improve survival, despite the increased risk of adverse effects," he said.
Physicians worry the risk of causing an adverse event is immediate and will be seen right away, possibly leading to a patient death and a lawsuit, while some of the benefits often are seen in a longer time frame, Shlipak said.
The research, which included 130,000 Medicare beneficiaries, is in Tuesday's Annals of Internal Medicine.
The study showed patients with mild and moderate kidney disease who got ACE inhibitors were 60 percent less likely to die within a month; with aspirin 50 percent less likely; and, with beta blockers 40 percent less likely to die in 30 days.
People who had heart attacks but no kidney disease got aspirin therapy 83 percent of the time, while 73 percent with mild and 64 percent with moderate kidney disease got aspirin. Aspirin tends to reduce clotting and inflammation.
Patients without kidney disease got beta blockers 50 percent of the time but only 39 percent of mild kidney disease patients and 31 percent of moderate kidney disease patients got them. Beta blockers reduce the heartbeat rate and strength of contraction.
The heart attack victims without kidney disease got ACE inhibitors 36 percent of the time, though more, about 46 percent with mild or moderate kidney disease, received them. The action of ACE inhibitors is complex, however. They tend to lower blood pressure and the heart does not need to work as hard.
About 92 percent of patients without kidney disease survived the first month following a heart attack, but only 80 percent with mild kidney disease and 60 percent with moderate disease survived 30 days.
People with kidney disease are not at higher risk from taking aspirin, according to Vincent W. Dennis, chair of nephrology and hypertension at the Cleveland Clinic Foundation in Ohio.
Regarding the lower percentage of patients with kidney disease treated with aspirin, Dennis told UPI, "I found that totally perplexing."
Cooperation among disciplines might help. "There is growing evidence that collaboration of care for these heart attack patients between the primary caregiver, whether a cardiologist or internist, and a nephrologist is beneficial, bringing about a greater likelihood of aggressive care and perhaps improved outcomes," said Richard A. Lafayette, associate chief for clinical affairs in nephrology at Stanford University School of Medicine, Palo Alto, Calif.
(Reported by Joe Grossman, UPI Science News, Santa Cruz, Calif.)
