Current guidelines recommend a patient-appropriate combination of antiplatelets, beta-blockers (BB), ACE inhibitors (ACEI)/ARB and statins to reduce the risk of MI and death from cardiac causes in all patients with coronary artery disease (CAD), but a study published online Oct. 30 in the Journal of the American College of Cardiology found that more than one-third of these patients did not receive whatever combination would have been appropriate for them. Prescribing practices varied widely, leading to the discrepancies.
“[L]ittle is known about secondary prevention medication prescription patterns among CAD patients in the outpatient setting,” wrote the authors, led by Thomas M. Maddox, MD, MSc, of VA Eastern Colorado Health Care System in Denver.
The researchers analyzed 2008 through 2010 data from the National Cardiovascular Data Registry (NCDR) PINNACLE registry, which contains information on quality improvement for outpatient cardiology patients seen in cardiology practices throughout the U.S. They analyzed prescription rates of the different medication classes and defined the optimal combined prescription as 100 percent if patients received all medication classes for which they were eligible. Primary analysis was based on the first visit to the practice.
Patients in the study all had CAD, which included prior MI, PCI or CABG and used BB, ACEI/ARB and statins. They did not include antiplatelets in their eligibility because the use of over-the-counter medications such as aspirin may not be represented in the registry data.
Patients eligible for enrollment who had a previous MI or a left ventricular ejection fraction (LVEF) less than 40 percent were treated with BB, those with diabetes mellitus or LVEF less than 40 percent were treated with ACEI/ARB and those with low-density lipoprotein (LDL) cholesterol greater than 100 mg/dL were treated with statins.
There were a total of 156,145 patients from 58 practices included in the study. Of these patients, 66.5 percent received 100 percent of the medications for which they were eligible at their first visit. When all visits in the year after the initial visit were included, the percentage increased to 69.7. The median optimal prescription rate by practice was 73.5 percent and the range was 28.8 percent to 100 percent.
After the researchers adjusted for various patient variables, the practice median rate ratio was 1.25, meaning there was a 25 percent likelihood that two practices would treat the same patients differently.
There could be a number of reasons why there was considerable variability among practices, such as incorrect classification of patient eligibility, incomplete documentation or factors that contraindicated the medications.
“Further investigation into reasons behind these practice-level differences is needed to provide the right care to the right patient, regardless where they seek that care,” the authors concluded.