The study, which followed 516 people with coronary artery disease for an average of more than three years, found that those who scored in the highest third on standard tests of anxiety had nearly double the risk of heart attack or death compared to those in the lowest third.
"It would be ideal now to see whether if we did something about it [anxiety], would that have an impact on prognosis. That has never been done before," said study author Dr Charles M. Blatt, director of research at the Lown Cardiovascular Research Foundation in Boston.
It's also unclear what kind of intervention - drug treatment or counselling - would work best, he added.
"But, even if we don't have evidence that intervening would be helpful, it makes so much common sense if you say that when anxiety is alleviated, the patient does better," Blatt said. "If the patient is allowed time to explain his or her anxieties, that would be helpful. But from a scientific point of view, I can't tell you with great assurance that if anxiety is alleviated, we do better with symptoms. We are trying to answer in a scientific way if there is benefit to be derived."
The findings will be published in the May 22 issue of the Journal of the American College of Cardiology.
In the study, people completed weekly questionnaires, answering such questions as whether they felt peaceful, whether they took a long time to fall asleep at night, or had upset bowels or stomach.Anxiety tied to heart risk
Every one-point increase in the anxiety score was associated with a 6 percent increase in the risk of death or heart attack in the study, Blatt noted.
The initial results of the study, based on a first test of anxiety, were not especially revealing, Blatt said. But, "the cumulative score - how it developed over time, increasing or declining - made a substantial difference in outcome," he said.
Those who started out highly anxious but later found more inner calm reduced their risk markedly, the researchers found.
A referral to a psychologist or psychiatrist might be appropriate for someone with extreme symptoms of anxiety, Blatt said. "But the power of reassurance that a cardiologist has with a patient is extraordinarily important," he added. "It is power that can be harnessed every day."Mechanism still unclear
The search is on for mechanisms relating psychological factors with their physical consequences, said Dr James L. Januzzi, director of the cardiac intensive care unit at Massachusetts General Hospital, who said he has "an active research interest in this area."
"Until we have that understanding of the mechanisms that connect worsening of mood and poor outcomes, it will be hard to develop interventions," Januzzi said.
He's currently working on identifying biomarkers of risk, such as inflammation and injury to the heart muscle, and then relating them to feelings such as anxiety and depression.
"We have found some interesting results," Januzzi said. "We can see a clear signal emerging, using measures of heart dysfunction. In doing so, we may be able to identify a target for treatment."
What seems plain is that "the era of 'it's all in your head' is over," Januzzi said. "There is an intimate connection between the neurovascular and cardiac system that remains unexplored as yet. Patients with anxiety and depression shouldn't feel stigmatised. There are real effects on organ systems other than the heart."
Another report in the same issue of the journal found a significantly increased risk of death in people with heart failure who also had sleep apnoea. The study of 88 people with heart failure found an average survival time of 45 months for those with sleep apnoea, defined as five or more breathing interruptions per hour, and 90 months for those without the breathing disorder.
The study, described as the largest of its kind, was done at the Cincinnati Veterans Affairs Medical Centre and the University of Cincinnati College of Medicine. – (HealthDayNews)Read more: