Nearly half the coronary artery disease (CAD) patients in a seven-year study admitted they don’t consistently take beta blockers, cholesterol-lowering drugs and other medications that could extend their lives, researchers report in Circulation: Journal of the American Heart Association.
Recent focus has been on ensuring that hospitalized patients are prescribed the proper preventive medications at discharge.“However, attention should also be focused on improving long-term and consistent use of those medications,” said Kristin Newby, M.D., lead author of the study and associate professor of medicine at Duke University Medical Center in Durham, N.C.Researchers examined changes in the prevalence and consistency of use of evidence-based secondary prevention medications. From 1995–2002, they found the use of therapies with proven survival benefit in CAD patients has improved.“However, their use remains less than what is optimally needed,” Newby said. “Consistent adherence to these medications was lower despite the fact that failure to use them was associated with lower survival rates.”Researchers tapped the Duke Databank for Cardiovascular Disease to analyze medication adherence among 31,750 patients who had undergone a cardiac procedure at Duke, had at least one coronary artery more than 50 percent blocked or had heart bypass surgery. All patients reported their use of aspirin, beta blockers and lipid-lowering drugs in annual surveys.Patients had to have at least two consecutive surveys returned during the study. Consistent use was defined as reporting use of medications on at least two consecutive occasions and continuing to report use through the end of the study period. Angiotensin-converting enzyme (ACE) inhibitors were reported for patients with and without heart failure. Researchers found the use of all drugs and combinations increased each year. By 2002:
- 83 percent of patients reported using aspirin; 61 percent reported using a beta blocker; 63 percent reported taking a lipid-lowering drug; 54 percent used aspirin plus beta blocker; and
- 39 percent reported using all three drugs.
However, consistent use during the study period was lower. Researchers found:
- 71 percent of patients said they used aspirin consistently; 46 percent adhered to beta blockers; 44 percent stuck with a lipid-lowering drug; 36 percent committed to aspirin plus beta blocker;
- and only 21 percent used all three consistently.
Among patients who had not experienced heart failure, 39 percent reported using ACE inhibitors in 2002; however, consistent use was at 20 percent. Among patients who had experienced heart failure, ACE inhibitor use was 51 percent in 2002 and consistent use was 39 percent.Consistent use of any of the therapies was associated with higher survival rates. An association was not found, however, among patients who used ACE inhibitors but had not experienced heart failure. Older patients, those with heart failure, smokers and diabetics were least likely to consistently take medication.“These are the groups with the highest risk of poor outcome, and therefore the groups that could potentially benefit the most from sustained therapy,” Newby said.As a remedy, she suggested educational and adherence intervention programs implemented via pharmacists and medical care providers.Researchers acknowledge that because the patients were mostly from North Carolina and southern Virginia, the results may not be representative of the entire U.S. population.“Patients with CAD, their families and their care providers should be familiar with the therapies that improve clinical outcomes and understand the importance of taking them regularly,” Newby said. “Each of these individuals plays a critical role in ensuring not only that the drugs are prescribed, but also that they continue to be taken during long-term management of CAD.”Newby said that teams of researchers, clinicians, nurses, pharmacists, policy-makers, patients and their families should continue to work on solutions to guarantee improved and consistent long-term use of evidence-based secondary prevention therapies.The study was supported in part by the Agency for Healthcare Research and Quality, Centers for Education and Research on Therapeutics.
Co-authors are Nancy M. Allen LaPointe, Pharm.D.; Anita Y. Chen, M.S.; Judith M. Kramer, M.D., M.S.; Bradley G. Hammill, M.A.; Elizabeth R. DeLong, Ph.D.; Lawrence H. Mulbaier, Ph.D. and Robert M. Califf, M.D.