Angina Hospitalization Guidelines Eased : Medicine: Low-risk heart outpatients advised to see their doctor within 72 hours after initial incident for determination of follow-up treatment.

Patients with unstable angina do not necessarily have to be hospitalized if they are otherwise at low risk for heart attacks and are seen by doctors again within 72 hours, federal health officials said Tuesday.

They issued guidelines for the condition that are intended to help doctors quickly determine the appropriate treatment for patients, including whether they should be admitted to hospitals or treated as outpatients.

Difficulty in diagnosing the condition and evaluating the degree of risk often have led to unnecessary hospital admissions, said Harvard University cardiologist Eugene Braunwald, who chaired the panel that drew up the guidelines.

Unstable angina is caused by underlying coronary heart disease and differs from stable angina in that it strikes at unexpected times, such as when an individual is sleeping or at rest. It occurs when the heart does not receive sufficient oxygen, usually as a result of clogged coronary arteries.

The condition is often difficult to diagnose because it can be confused with other medical problems. Many persons suffering from unstable angina are unaware that they have heart disease, the leading killer of American adults.

The guidelines, released in Atlanta at the annual meeting of the American College of Cardiology, were developed by a panel of 19 private sector experts in a process managed by Duke University Medical Center and co-sponsored by the agency and by the National Heart, Lung and Blood Institute--a branch of the National Institutes of Health.

According to the guidelines, only about half of all cases of unstable angina require hospitalization, while the rest can be treated on an outpatient basis. Patients, however, must be accurately evaluated in the emergency room before being sent home to be certain that they are at no immediate risk of a heart attack, the agency said.

Those patients can be treated with aspirin or other blood thinners and released, as long as they are again evaluated within 72 hours, the agency said.

“Accurate diagnosis of unstable angina is very important for patients in the hospital emergency room,” said Dr. J. Jarrett Clinton, administrator of the agency. “It ensures that patients at risk of heart attack are admitted and placed in coronary care units where appropriate care is available. Accurate diagnosis also steers low-risk patients--those not in imminent danger--into outpatient care.”

Nevertheless, the guidelines stressed that anyone experiencing chest pains of “unusual character, severity or duration” should go immediately to a hospital emergency room for evaluation.

Admissions to hospitals for unstable angina rose more than fourfold between 1983 and 1991, from 130,000 to 570,000, totaling 3.1 million hospital days, according to the Agency for Health Care Policy and Research, part of the U.S. Public Health Service of the Department of Health and Human Services.

The guidelines also recommended that:

* All patients believed to have unstable angina should be evaluated initially with a physical exam and electrocardiogram.

* Drugs for initial treatment should include aspirin, nitroglycerin, beta blockers and heparin and calcium channel blockers should not be the first-line approach, although they are frequently administered first.

* Patients believed to be at intermediate or high risk of heart attack or death should be admitted to a coronary care unit and should include individuals who have suffered more than 20 minutes of pain at rest, those with fluid on the lungs, heart murmurs or low blood pressure.

* Patients who do not respond to treatment within 30 minutes should be considered candidates for catheterization, that is, placement of a tube into the heart to detect blockages. Bypass surgery or angioplasty ultimately should be considered.