The finding, from a 10-year study of more than 4,300 Americans, suggests that the stress relief pets provide humans is heart-healthy.
And dog lovers shouldn't feel left out: Although the study found no such benefit from "man's best friend," that's probably because there simply weren't enough dog owners in the study to draw firm conclusions, the researchers said.
"For years we have known that psychological stress and anxiety are related to cardiovascular events, particularly heart attacks," noted study senior author Dr. Adnan Qureshi, executive director of the Minnesota Stroke Institute at the University of Minnesota in Minneapolis.
According to Qureshi, the new research shows that "essentially there is a benefit in relieving those inciting factors from pets."
He was slated to present the findings Thursday at the American Stroke Association's International Stroke Conference in New Orleans.
The stress-cardiovascular disease link is well-documented in scientific literature, and the affection and pleasure pets give humans is a known stress-buster. In fact, one study presented in 2005 at an American Heart Association meeting found that a single 12-minute visit with a dog improved the heart and lung function of people with heart failure.
In the new study, Qureshi's team analyzed data on 4,435 Americans, aged 30 to 75, who took part in the federal government's second National Health and Nutrition Examination Study, which ran from 1976-1980. According to the data in the survey, 2,435 of the participants either owned a cat or had owned a cat in the past, while the remaining 2,000 had never done so.
Qureshi's team then tracked rates of death from all causes, including heart and stroke.
Cat owners "appeared to have a lower rate of dying from heart attacks" over 10 years of follow-up compared to feline-free folk, Qureshi said.
The magnitude of the effect -- a 30 percent reduction in heart attack risk -- "was a little bit surprising," he added. "We certainly expected an effect, because we thought that there was a biologically plausible mechanism at work. But the magnitude of the effect was hard to predict."
Qureshi -- proud owner of his own feline, Ninja -- stressed that dogs probably would bring people the same kind of benefit, but the numbers of dog owners in the study wasn't big enough to count statistically.
Kathie Cole, a clinical nurse at the UCLA Medical Center and School of Nursing and the lead author of the 2005 dog-and-heart-failure study, said she wasn't surprised by the Minnesota findings.
"I would be inclined to think that any animal that is perceived as meaningful to a person in a positive way would have health benefits," Cole said. She pointed to multiple studies that have found that animal companions "have a calming effect in regard to mental stressors."
Both researchers believe pet ownership should be perceived as a low-cost, low-risk medical intervention that can potentially save or extend lives, especially for the elderly. "The problem right now is that so many apartment buildings or nursing homes aren't allowing animals in," Cole said. "That's the problem I see from a community standpoint."
Qureshi agreed that cats, dogs or other pets may bring tangible medical benefits to owners.
"This opens a whole new avenue or intervention that we hadn't looked at before, one that can be made at the public level," he said. And unlike drugs or surgery, pet ownership "doesn't appear to have any risks to it," he added.