Poor communication may lead some patients with chest pain to be admitted to the hospital even when their risk for a heart attack is low, a small study suggests.

"Ideally, you want the conversation between a physician and a patient to be as straightforward as possible, but in our study of admissions for cardiac observation, we found the risks of going home were terribly overinflated and so was the potential benefit of staying overnight in the hospital," said lead study author Dr. David Newman.

Newman, a researcher in emergency medicine at the Icahn School of Medicine at Mount Sinai in New York City, and his colleagues surveyed 425 pairs of doctors and patients shortly after the patients were admitted to the hospital for acute coronary syndrome, an umbrella term for situations such as a heart attack or unstable angina where blood flow to the heart is suddenly blocked.

Symptoms can include chest pain, as well as nausea, dizziness and shortness of breath, as well as pain or discomfort in one or both arms, the jaw, neck, back or stomach. Risk factors include smoking, high blood pressure, high cholesterol, diabetes and obesity.

The researchers excluded patients from the study who had a blood test or an electrocardiogram (ECG) confirming that they had acute coronary syndrome.

Instead, they focused only on how doctors and patients communicated when lab tests did not definitively suggest that hospital admission was necessary.

The average age of patients in the study was 58, and the group was roughly half men and half women. Slightly more than half of the patients had annual incomes of $50,000 or less. About 40 percent had no education beyond high school.

Patients reported that their physicians spoke to them about their chances of having a heart attack in 65 percent of cases, but the doctors said they discussed this in only 46 percent of cases.

Doctors and patients agreed about the heart attack risk only one third of the time, the study found.

Asked about the odds of a heart attack or other acute event within the next 30 days, doctors said this was possible in five percent of cases, while patients said this eight percent of the time. The average risk for this patient population should be less than two percent, the researchers write in the Annals of Emergency Medicine.

"Part of the problem could be a difference in risk tolerance between physicians and patients," said Dr. Erik Hess, a researcher in emergency medicine at the Mayo Clinic in Rochester, Minnesota, who wrote an editorial accompanying the study. "A low risk to physicians is you don't want anyone going home with a myocardial infarction. If a patient learns their risk is two percent they may be willing to take that risk if it means not staying in the hospital overnight."

Because the researchers didn't collect outcomes data on patients, the study couldn't confirm whether less than two percent of the participants actually had an adverse event. They also relied on physicians and patients to correctly recall conversations about the diagnosis and risks, instead of using audio or video recordings to verify what was discussed.

Still, the findings speak to the need for a communication breakdown to be repaired, said Dr. Daniel Munoz, who teaches cardiology at Vanderbilt University Medical Center in Nashville, Tennessee.

"What's striking is that they were very careful to select patients who weren't in the active throes of a heart attack and who didn't have an alarming ECG, and both the physicians and the patients still overestimated the risks," said Munoz, who wasn't involved in the study.

The danger of poor communication about risks, beyond the unnecessary tests and hospitalizations, is the waste of limited resources, said Newman. "People admitted for a cardiac stay can easily get a $5,000 to $10,000 workup in one night, resources that you could spend giving one person primary care for an entire year."