March 30, 2007

Study finds medical therapy alone effective for stable heart patients

Featured Image

David Maron, M.D., talks with patient Dolores Benedict. (photo by Susan Urmy)

Study finds medical therapy alone effective for stable heart patients

Results were released this week from a study examining the effectiveness of stenting when combined with medical therapy in patients with stable coronary artery disease.

The COURAGE Trial (Clinical Outcomes Utilizing Revascularization and Aggressive DruG Evaluation) is the first study specifically designed to assess the benefit of combining Percutaneous Coronary Intervention (PCI) and intensive medical therapy, versus medical therapy alone.

Investigators found that optimal medical therapy without routine PCI can be implemented safely in the majority of patients with stable coronary artery disease — without sacrificing quality of care or clinical outcomes.

The study was published this week in the New England Journal of Medicine.

Many studies have been conducted to determine the individual roles of medical therapy, PCI and bypass in patients with coronary artery disease, but investigators measured the major endpoints — death or nonfatal heart attacks — that occurred in each study group to determine if the addition of stenting or PCI to aggressive medical therapy reduced the risk of death or heart attack. Medical therapies included anti-platelet therapy (aspirin and or plavix), statins, beta-blockers, ACE inhibitors, smoking cessation and diet and exercise regimes.

The trial, the largest randomized study of its kind, was designed in part by Vanderbilt University Medical Center's David Maron, M.D., associate professor of Medicine. Maron began designing the trial in 1994 shortly after his arrival at Vanderbilt.

“Our hypothesis was that the combination of stenting plus optimal medical therapy would be better than medical therapy alone,” said Maron.

“We found no difference between the groups in the number of deaths and nonfatal heart attacks. We also looked at secondary endpoints such as hospitalization for acute coronary syndromes, and there was no difference.

“Once we determined there was no difference in major cardiovascular endpoints, we turned our attention to how effectively the different management strategies treated angina.

“At baseline, 88 percent of the patients enrolled in the study had angina. At 3 years into the study, 72 percent of those in the PCI group were angina free, compared to 67 percent of those randomized to the medical therapy group.

“The difference was statistically significant in favor of PCI,” said Maron. By 5 years into the study, 74 percent of the PCI group was angina free, compared to 72 percent in the medical therapy group. This difference was not statistically significant.

During the trial, one-third of patients initially randomized to the medical therapy arm of the study “crossed over” to receive PCI for control of angina.

“Although PCI plus medical therapy was superior to medical therapy alone for treatment of angina, the improvement in angina for both groups was considerably greater than the difference between the two groups,” said Maron. “I was amazed at how well the medical therapy group did in terms of angina control.”

Maron said the study's findings reinforce existing guidelines stating that PCI can be safely deferred in patients provided that evidence-based medical therapy is instituted.

“We and our patients have grown accustomed to turn to PCI whenever we discover a narrowed artery causing chest pain.

“Our study found that even when there is severe narrowing in the coronary artery, it is just as safe in a stable patient to try medication and lifestyle measures first,” he said.

According to Maron more than one million stenting procedures are performed in the United States each year, with at least half of those procedures done on patients with stable coronary disease.

Despite the decline in the death rate linked to heart disease over the past three decades, it remains the single largest cause of death in the world.

Maron and a team of investigators are in the midst of analyzing data collected during the COURAGE Trial to determine quality of life outcomes and cost effectiveness of the two management strategies.

The trial enrolled more than 2,200 patients from 50 sites in the United States and Canada between 1999 and 2004. Participating sites in this country were Veterans Affairs hospitals and non-VA centers that are predominately academic medical centers.

Local investigators along with Maron were Raphael Smith, M.D., professor of Medicine emeritus at the Nashville VA, David Hansen, M.D., associate professor of Medicine at Vanderbilt, and Carol Mitchell, R.N. (study coordinator).