Low statin use in people with diabetes despite cardioprotective effects, guidelines

Previous studies have shown that taking a statin can significantly cut the risk of a future cardiovascular event in people with diabetes. Researchers say this study is one of the first to look at real-world trends in the use of statin therapy in this patient population and is intended to help inform and potentially improve practice performance and, ultimately, patient outcomes.

"Patients with diabetes, including those without established cardiovascular disease, have a very high risk of having a heart attack or stroke, and they are also more likely to die of one compared to people without diabetes," said Salim Virani, M.D., Ph.D., cardiologist at the Michael E. DeBakey VA Medical Center, associate professor at Baylor College of Medicine in Houston and senior author. "In this study, we found 38 percent of patients with diabetes were not on a statin, which can be lifesaving."

Even when patient factors such as age, gender, race, high blood pressure, high cholesterol, tobacco use and insurance coverage were accounted for, there was a 57 percent practice-level variation in statin use. Virani said this means that if you take two similar patients, one is 57 percent more likely to be prescribed statin therapy on average than a similar patient receiving care at another practice. By comparison, an earlier analysis of statin use among similar patients within the VA health care system showed only 20 percent facility-level variation, which Virani said is likely a reflection of more consistent care, uniform protocols and information technologies, and more consistent medication formulary choices compared to individual cardiology practices.

"Such wide variation illustrates the gap between guideline recommendations and real world practice. Health care providers manage similar diabetes patients differently," Virani said. "While some variation is OK, what we found is concerning and may ultimately affect clinical outcomes."

In November 2013, the American College of Cardiology and the American Heart Association issued guidelines stating that unless contraindicated, statin therapy should be started and maintained in 40-75 year old patients with diabetes whose LDL cholesterol level is ≥70 mg/dL based on an assessment of risk to prevent the development of cardiovascular disease. The American Diabetes Association similarly recommends that a statin be used to supplement lifestyle changes in people with diabetes who are 40 and older, regardless of baseline LDL cholesterol levels or whether they have cardiovascular disease.

Researchers examined practice-level variations in statin therapy among 40-75 year old patients with diabetes and no overt cardiovascular disease between May 2008 and October 2013 (before the present guidelines were issued) from the American College of Cardiology's PINNACLE registry, a national cardiology outpatient quality improvement registry that extracts data directly from electronic medical records. Statin use was defined as its prescription at any time point during the study period, as documented in the medical records. A total of 215,193 patients (582,048 encounters) from 204 cardiology practices were included in the analysis. Compared with patients not receiving statins, those on statins had a higher prevalence of cardiovascular risk factors, were also more likely to receive non-statin cholesterol-lowering therapy (28 vs. 13 percent) and had lower mean LDL cholesterol readings (90 mg/dL vs. 103 mg/dL).

In order to assess the relevance of the study findings in light of evolving clinical guidelines, the researchers also evaluated the results and practice level variation in patients whose LDL-C was <100 mg/dL, a level that had been the commonly accepted treatment goal per the earlier ATP III guideline. The gaps in treatment and the facility level variation by LDL-C levels <100 mg/dL were very similar to the main study results (57.7 and 47 percent, respectively), which suggests the findings are not just related to which guideline is used to measure quality, Virani said.

The researchers stress that the findings underscore the urgent need to intensify national efforts to improve guideline-concordant use of statins in patients with diabetes. One step is for patients and treating providers to talk about how to prevent a heart attack, stroke or related death in the future at every opportunity.

"When these types of discussions happen, patients are more likely to receive evidence-based therapies including statins," he said. "Once one is prescribed, it's important that patients take them and report any problems to their health care provider."

Statins work in several ways, including lowering or removing cholesterol and the buildup of plaque in the arteries and reducing inflammation.

While patients did not have overt cardiovascular disease, because they were seen at a cardiology practice, they may have had an acute cardiology-related issue and may not be representative of the general diabetes population. Virani said an important next step is to identify barriers to statin use and leverage and test electronic medical record alerts and decision support tools at the point of care to improve guideline-driven statin use for risk reduction when appropriate.