News in brief - Sept. 20, 2004

Study links high doses of arthritis meds to increased heart attack risk - Medication comparable to surgery for elderly chest pain patients - Study calls omega-3 fatty acid super brain food against Alzheimer's disease - Cancer risk from full-body scans?

Study links high doses of arthritis meds to increased heart attack risk

Taking more than 25 mg per day of rofecoxib (Vioxx) is linked to a tripling of the risk of heart attack, said a paper presented in August at the International Society for Pharmacoepidemiology Conference in Bordeaux, France.

Researchers analyzed data from the HMO Kaiser Permanente for all patients prescribed COX-2 inhibitors or non-steroidal anti-inflammatories. Patients on higher doses of rofecoxib increased their heart attack risk by a factor of 3.15. No increase was found in patients taking another COX-2 inhibitor, celecoxib (Celebrex).

Kaiser intends to re-evaluate use of this drug based on this information.

The manufacturer disagreed with the conclusions of the study.

"Observational analyses do not have the rigor of randomized, controlled clinical trials. ... Based on the data that are available from our clinical trials, Merck stands behind the efficacy and safety, including cardiovascular safety, of Vioxx," said Peter S. Kim, PhD, president of Merck Research Laboratories.

Medication comparable to surgery for elderly chest pain patients

Patients older than age 75 with chronic angina do just as well with invasive treatment as with medication alone, says a study published online last month in Circulation: Journal of the American Heart Assn.

Researchers at University Hospital in Basel, Switzerland, studied 300 random patients who received either an optimal medication regimen including aspirin, statins and angiotensin-converting enzyme inhibitors or a surgical procedure such as coronary artery bypass graft or percutaneous coronary intervention.

Survival rates were similar after five years, although those on medications alone required higher doses throughout the study. This group also had more nonfatal events, such as recurrent hospitalizations, and 43% ended up having at least one surgical procedure before the end of the study.

Authors of the paper suggest that both treatment strategies can be appropriate options for providing care to this population.

Study calls omega-3 fatty acid super brain food against Alzheimer's disease

A diet high in the omega-3 fatty acid DHA, or docosahexaenoic acid, helped protect the brains of mice genetically engineered to behave like the brains of people with Alzheimer's disease from the memory loss and cell damage caused by the disease, said a study published in the Sept. 2 issue of the journal Neuron.

"Consuming more DHA is something the average person can easily control," said Greg Cole, PhD, senior author of the study and professor of neurology at the David Geffen School of Medicine at the University of California at Los Angeles. "Anyone can buy DHA in its purified form, fish-oil capsules, high-fat fish or DHA-supplemented eggs."

The researchers were using mice bred with genetic mutations that cause the brain lesions linked to advanced Alzheimer's disease to test environmental risk factors for the disorder when they noticed that, while the mice were developing the lesions, they showed minimal memory loss or synaptic brain damage.

They next took a closer look at the animals' diet and found it was chock-full of omega-3 fatty acids. Additional tests led to the conclusion that the DHA-enriched diet was holding their genetic disease at bay, Dr. Cole said.

Cancer risk from full-body scans?

There is a modest, but not negligible, risk of cancer from a single, full-body CT scan, said a study in the September issue of Radiology, and the risk rises considerably if a person has elective annual scans over a number of years.

"The radiation dose from a full-body CT scan is comparable to the doses received by some of the atomic-bomb survivors from Hiroshima and Nagasaki, where there is clear evidence of increased cancer risk," said David J. Brenner, PhD, DSc, lead author of the study and professor of radiation oncology and public health at Columbia University in New York City.

The study found that a 45-year-old who underwent one full-body CT screening would have an estimated lifetime cancer mortality risk of approximately 0.08%, which would produce cancer in one in 1,200 people. But a 45-year-old who has annual full-body CT scans for 30 years would accrue an estimated lifetime cancer mortality risk of about 1.9% or almost one in 50 people.

The report considered risk only for asymptomatic adults who elect to undergo high-tech checkups. "The risk-benefit equation changes dramatically for adults who are referred for CT exams for medical diagnosis. Diagnostic benefits far outweigh the risks," Dr. Brenner said.