Researchers at Intermountain Medical Center in Salt Lake City believe they have made a breakthrough connection between atrial fibrillation, a fairly common heart rhythm disorder, and Alzheimer's disease, the leading form of dementia among Americans.
The researchers unveiled findings from their study of more than 37,000 patients that showed a strong relationship between the two May 15 at "Heart Rhythm 2009," the annual scientific sessions of the Heart Rhythm Society in Boston.
The study, which drew upon information from the Intermountain Heart Collaborative Study, a vast database from hundreds of thousands of patients treated at Intermountain Healthcare hospitals, found:
• Patients with atrial fibrillation were 44 percent more likely to develop dementia than patients without the heart disorder.
• Younger patients with atrial fibrillation were at higher risk of developing all types of dementia, particularly Alzheimer's. Atrial fibrillation patients under 70 were 130 percent more likely to develop Alzheimer's.
• Patients who have both atrial fibrillation and dementia were 61 percent more likely to die during the study period than dementia patients without the rhythm problem.
• Younger atrial fibrillation patients with dementia may be at higher risk of death than older AF patients with dementia.
"Previous studies have shown that patients with atrial fibrillation are at higher risk for some types of dementia, including vascular dementia," said T. Jared Bunch, M.D., a cardiologist at Intermountain Medical Center who was the study's lead researcher and who presented the findings at the scientific session. "But to our knowledge, this is the first large-population study to clearly show that having atrial fibrillation puts patients at greater risk for developing Alzheimer's disease."
Alzheimer's is a devastating brain disease affecting about 5.3 million Americans. It is the most common form of dementia (a general term for life-altering loss of memory and other cognitive abilities), and accounts for 60 percent to 80 percent of all dementia cases. Today, it is the sixth-leading cause of death in the United States.
Currently, the known risk factors for Alzheimer's are age, family history and genetics, though injury may also be linked with the disease. Heart health has long been suspected to play a role, but has not been linked. The Intermountain Medical Center study bolsters that connection.
"The study shows a connection between atrial fibrillation and all types of dementia," Bunch said. "The Alzheimer's findings — particularly the risk of death for younger patients — break new ground."
Atrial fibrillation is the most common heart rhythm problem, affecting about 2.2 million Americans. It occurs when the heart beats chaotically, leading blood to pool and possibly clot. If the clot leaves the heart, a stroke can result.
The Intermountain Medical Center study looked at five years of data for 37,025 patients. Of that group, 10,161 developed atrial fibrillation and 1,535 developed dementia during the study period.
The study authors say more research is needed to explore further the relationship between atrial fibrillation and the development of Alzheimer's disease.
"Now that we've established this link, our focus will be to see if early treatment of atrial fibrillation can prevent dementia or the development of Alzheimer's disease," says cardiologist John Day, M.D., heart rhythm services director at Intermountain Medical Center and a co-author of the study.
Editor’s Note: Doctor: Protect Your Brain From Alzheimer's, Parkinson's Today!
Sinus Surgery Relieves Stubborn Sinusitis
When standard medication treatment fails, sinus surgery can relieve all major symptoms typically associated with chronic rhinosinusitis, including nasal obstruction, facial pain, postnasal discharge, headache, and smell disturbances.
That's according to a meta-analysis of 21 studies involving a total of 2070 patients with chronic rhinosinusitis who were followed for an average of 13.9 months after surgery. The results are reported in the journal Otolaryngology — Head and Neck Surgery.
This is the first meta-analysis that has focused on symptom relief following endoscopic surgery and "gives the largest body of evidence that improvement is noted generally," said Dr. Alexander C. Chester of Georgetown University Medical Center in Washington, D.C.
"It has never been clear about which symptoms improve the most and there was some concern about smell disturbances not improving, so it was important to pool the study results," Chester told Reuters Health.
The meta-analysis showed that all symptoms improved significantly following endoscopic sinus surgery; the overall average effect size was 1.19.
"This is a strong effect size," Chester pointed out, given that any effect size greater than 0.8 is considered large.
The effect size was most prominent for nasal obstruction (1.73), followed by facial pain (1.13), postnasal discharge (1.19), headache (0.98), and excessive sleeping (0.97).
In before-and-after analyses, nasal obstruction, facial pain, headache, smell and postnasal discharge improved by roughly 59 percent, 61 percent, 53 percent, 49 percent, and 47 percent, respectively, following surgery.
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