Regional variations in the use of heart drugs

While the use of different therapies to treat or prevent heart attacks varies widely across the United States and Canada, Duke researchers found that regions with the highest use of percutaneous coronary interventions had the lowest rates of evidence-based medications.

The Duke researchers wanted to see how the different regions of the country used the following proven therapies -- aspirin, beta blockers, ACE inhibitors and percutaneous coronary interventions, such as angiography and angioplasty -- for improving survival of heart patients.

Unlike the other therapies, aspirin was used uniformly in more than 95 percent of the patients across the regions.

The researchers, led by DCRI cardiology fellow Dr. M. Cecilia Bahit, studied the data collected during ASSENT II, an international trial that enrolled 16,949 heart attack patients between October 1997 and November 1998. Of that group of patients, 4,806 (28 percent) were treated in the U.S. and Canada.

"In the ASSENT II trial, 87 percent of the �eligible' patients who would benefit from beta blockers actually received the drug," Bahit said. "That is up from 72 percent from another large trial (GUSTO-I) in the early 1990s, but it stills shows we have room for improvement."

Some of the regional characteristics include:

-- The West-Central United States had the highest rate of percutaneous interventions (53 percent) while New England had the lowest rate (36 percent).

-- The Mid-Atlantic region and New England used beta blockers 92 percent of the time, while the West-Central region had the lowest (82 percent).

-- ACE inhibitors were least used in the East-Central U.S. (42 percent) and most used in the Mid-Atlantic region (51 percent).

-- Canada, which has a different health care system than the U.S., used percutaneous coronary interventions far less frequently (13 percent) and had higher use rates of beta blockers (85 percent) and ACE inhibitors (52 percent).

"This is a snapshot of how these therapies are used in North America," Bahit said. "We do not know why there is a such a disparity between regions of the U.S., especially since the health care system is much the same. If we could better understand these regional differences, we could be able to improve the care for our patients.

"The bottom line is that while we are getting better, we can still save many more lives if more doctors put into practice what we learn from these clinical trials," she said.

The analysis was supported by the Duke Clinical Research Institute.