Duke Study Finds Key Heart Drug Underutilized
NEW ORLEANS, LA -- It's the old good news-bad news scenario - the use of a highly effective heart disease medication has increased over the past decade, but it is still being woefully underutilized by cardiologists, according to a Duke Clinical Research Institute study.
While many large-scale clinical trials have clearly demonstrated that the class of medications known as angiotensin converting enzyme (ACE) inhibitors can significantly reduce the risk of death, heart attacks and heart failure complications for those patients most at risk, physicians are at best prescribing these drugs in just over half the cases they should, said Duke cardiologist Dr. Darren McGuire.
After analyzing the data of seven multi-center trials conducted throughout the 1990s involving a total of more than 100,000 patients, McGuire discerned a small, yet steady, increase in the use of ACE inhibitors over the decade.
"ACE inhibitors have been used for many years, and we know that they are very safe and effective at improving important clinical outcomes," said McGuire. "While the trend is improving, which is good news, as many as one-half of all heart patients are not receiving a medication that we know will benefit them."
McGuire prepared the results of his study for presentation Monday at the 73rd annual Scientific Sessions of the American Heart Association. The data analysis was funded by the Duke Clinical Research Institute (DCRI).
The first major trial of 1990s, GUSTO-I, which ran from 1990-93, showed a usage of ACE inhibitors of
18.7 percent, while the ASSENT-2 trial, completed in 1998, showed a usage of just over 50 percent. The five trials in between chronicled the gradual increase of usage from 20 percent to 50 percent.
McGuire explained that often in medicine, there can be a 7- to 10-year lag between the time clinical trials prove the benefits of a particular treatment and the widespread acceptance of the findings and usage by physicians. While this is the general case, McGuire said he is nonetheless disappointed by the low usage of ACE inhibitors, since the evidence supporting their benefits is so clear.
"There have been seven large trials this decade proving their benefits, the evidence has been widely publicized in the press and on the Internet, and leading organizations such as the American Heart Association and the American College of Cardiology now recommend the use of ACE inhibitors in virtually every patient with heart disease," McGuire said.
In the case of ACE inhibitors, the patients at the highest risk for a heart attack are those who benefit the most from the drug - those with weakened heart pumping capabilities, congestive heart failure, diabetes or hypertension.
"There has always been the challenge of translating what we learn in clinical trials into direct patient care," McGuire said.
In the case of ACE inhibitors, McGuire believes that some form of oversight or auditing system - whether it be by physician groups or hospitals - should be used to ensure that whenever these types of patients are treated by physicians, they seriously consider the use of ACE inhibitors.
"Many hospitals and physician practices follow care maps for specific disorders that outline the latest and best practices available," McGuire said. "This could be an effective manner for making sure these patients receive the best treatments available."
As an example of a successful strategy, McGuire cited a recent study by 54 German hospitals participating in the MITRA (Maximal Individual Therapy in AMI) registry, which found that in the mid-1990's, only 15 percent of their heart attack patients were discharged with a prescription for a successful class of cholesterol-lowering drugs known "statins." When physicians were then asked to state on discharge forms whether or not that drug was considered, the usage rate jumped to 77 percent, McGuire said.
The key, McGuire said, is education, whether the efforts be targeted at physicians to increase their usage of the drug, or at patients, so they can inquire about the drug if it isn't being prescribed for them. The Internet can play an important role in both physician and patient education, he added.
However, the time-lag in the widespread acceptance of evidence-based medicine among physicians may be a situation difficult to overcome, he said
Earlier this year, McGuire conducted a small study to see how physician practice patterns change once they learn about the results of a major clinical trial. In his analysis, he looked at the influence of the results of a trial called BARI (for bypass angioplasty randomized investigation), which suggested that diabetic heart patients with coronary artery disease should receive bypass surgery instead of angioplasty, on clinical practice. In this analysis, there was no measurable effect of the trial results on clinical practice among 13 high-volume cardiology practices up to two years after the BARI results were reported.
"Physicians knew about the study and its results, but it had no measurable impact on their treatment choices," McGuire said. "It appears that they continue to believe what they are doing is right, even in the face of evidence to the contrary."
McGuire and his colleagues plan to conduct similar usage studies on other heart medications whose benefits have been proven by clinical trials, such as thrombolytic drugs (clot busters), glycoprotein IIb/IIIa platelet inhibitors, statins and beta-blockers.
Joining McGuire in the current study were, from the DCRI, Dr. Matthew Roe, Eugenia Bastos, Peter Joski and Dr. Robert Harrington. Other colleagues were Dr. Maarten L Simoons, Erasmus University, Rotterdam, Netherlands, and Dr. Harvey White, Green Lane Hospital, Auckland, New Zealand.