By William J. Cromie

Gazette Staff

All that exercise, dieting, quitting smoking, new drugs, and new technologies have taken their toll. Without them 127,000 more people in the U.S. would have died from heart disease between 1980 and 1990, according to researchers at the School of Public Health.

From 1960 to 1980, decreases in deaths were due mainly to lowering cholesterol and blood pressure and to stopping smoking. With those changes firmly in place, improvement in caring for those who have already experienced a heart attack has been the main force in driving down the death rates from 1980 to 1990.

"If nothing had changed with regard to reducing risk factors for heart disease, improving survival after a heart attack, and preventing subsequent attacks, we predict that there would have been 127,000 more deaths," declares Milton Weinstein, Kaiser Professor of Health Policy and Management.

"Our analysis suggests that only about one-fourth of this decline in mortality was owing to primary prevention [such as lower blood pressure, lower cholesterol, or quitting smoking]. Most of the decline [72 percent] was explained by improvement in the management of patients already diagnosed with coronary heart disease."

"What startled us was that treating patients with coronary heart disease was having so much more effect than trying to prevent the disease," notes Maria Hunink, an associate professor at both the School of Public Health and the University of Goningen in the Netherlands. "Primary prevention still has an important role to play but most of its effect was realized before 1980."

Technology that reduced the death toll includes increased use of cardiopulmonary resuscitation (CPR), clot-busting drugs given at the time of a heart attack, bypass surgery, angioplasty, and drugs to prevent additional attacks. In the bypass surgery, clogged heart arteries are bypassed with veins transplanted from the legs. In angioplasty, a thin tube containing a deflated balloon is threaded into a heart artery, then the balloon is inflated to push the blockage aside. Sometimes a small cagelike stent is implanted to keep the coronary artery open.

Drugs such as beta blockers and angiotensin-converting enzyme (ACE) inhibitors also have proved effective at preventing second heart attacks.

Although the death rate has fallen, the total number of heart-disease deaths actually increased between 1980 and 1990. This is because the U.S. population has increased and with it the prevalence of heart disease in men and women of all ages. Heart attack is still the single largest killer of Americans.

Role of Cholesterol

In the decade of the 1980s, people consolidated gains achieved in 1960-80 by exercising, dieting, quitting smoking, lowering blood pressure, and reducing cholesterol levels.

In 1980-90, lowering so-called bad cholesterol (low-density lipoprotein) and raising good cholesterol (high-density lipoprotein) by drugs or diet accounted for one-third of the decline in mortality.

"The potential impact of cholesterol-lowering medications appears to be substantial," notes the report. "Results from the current study indirectly support the notion demonstrated in other studies that treating high cholesterol in patients with heart disease is more cost-effective than primary prevention," that is, lowering cholesterol before signs of heart disease appear.

"Those who don't have heart disease, as well as those who do, must attend to keeping their cholesterol levels down by diet and drugs," Weinstein cautioned. "Everyone has to keep at this, as well as keeping blood pressure down and not smoking."

"Our study shows that people have done a good job in preventing death from heart disease," he continued. "We should pat ourselves on the back but not get too complacent."

About 700,000 people still are hospitalized with heart attacks, and about 500,000 die from coronary heart disease each year in the U.S. That toll costs the nation an estimated $80 billion each year, or about 15 percent of the health-care budget.

A full report of this research appears in yesterday's issue of the Journal of the American Medical Association. In addition to those from Harvard, the authors include researchers from the University of California, San Francisco; Dartmouth-Hitchcock Medical Center in New Hampshire; and the University of Cincinnati.