Statins May Help Prevent Irregular Heartbeat in Elderly
WEDNESDAY May 9, 2012 -- The widely used class of cholesterol-lowering medications known as statins may help elderly patients with high blood pressure avoid developing atrial fibrillation, a heart rhythm abnormality tied to stroke.
"Our study found that statin therapy in elderly patients with hypertension reduces the risk of new-onset atrial fibrillation," said Dr. Chen-Ying Hung, lead author of a study scheduled for presentation Wednesday at the Heart Rhythm Society's annual meeting in Boston.
But the findings are extremely preliminary and don't provide enough evidence to support this particular use of statins, such as Lipitor (atorvastatin) and Zocor (simvastatin) just yet, said the study authors and outside experts alike.
"We still need further studies to confirm this relationship before we can suggest statin use in [this population]," said Hung, a fellow at the Cardiovascular Center at Taichung Veterans General Hospital in Taiwan, which supported the research.
Other experts agreed.
"We have to be careful about jumping to final conclusions based on studies which are not primarily designed to look at this particular phenomenon," added Dr. Yisachar Greenberg, director of electrophysiology at Maimonides Medical Center in New York City. "This needs to be repeated and confirmed."
Millions of people around the world take statins to treat and prevent coronary disease, but they are also being studied for other indications, such as preventing dementia.
Hung and his collaborators reviewed medical records of 1 million individuals included in a large insurance database in Taiwan. Of about 27,000 patients aged 65 and older, nearly 9 percent took statins. Overall, during a nine-year follow-up, more than 2,200 individuals developed atrial fibrillation.
At the end of the follow-up period, statins had reduced the risk of atrial fibrillation by 19 percent in patients with or without other medical problems, such as diabetes, stroke and kidney disease.
The statins were particularly effective among patients with a higher CHADS2 score, a measurement developed to predict the odds of stroke in patients who already had atrial fibrillation (AF). The score takes into account the presence of congestive heart failure, hypertension and other factors, and recent studies have shown that it can also be used to estimate the risk of stroke in people who don't have atrial fibrillation, Hung said.
"The study is the first to explore the relationship between the AF protective effect of statins and the CHADS2 score," he added.
Dr. Kenneth Ong, interim chief of cardiology at the Brooklyn Hospital Center in New York City, said "statins do reduce inflammation, and inflammation has been associated with atrial fibrillation."
But Ong questioned the validity of the CHADS2 findings. "Although the CHADS2 score may be a practical way of identifying patients who can potentially be treated with statins, it's not a tested method," he said. "They didn't use the score to test a hypothesis. They just examined the data, which may or may not be legitimate."
However, Hung said there are some reasons to believe that statins could affect atrial fibrillation through various methods, including improved lipid (blood fat) metabolism; prevention of atherosclerosis, a build-up of plaque in the arteries, and endothelial dysfunction; and anti-inflammatory and antioxidant actions.
Serious side effects with statins are unusual, but the U.S. Food and Drug Administration recently insisted on label changes alerting users to problems with blood sugar levels and rare cases of confusion and memory loss.
Data and conclusions presented at medical meetings should be considered preliminary until published in a peer-reviewed medical journal.
The U.S. National Library of Medicine has more on atrial fibrillation.
Posted: May 2012
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