Disclosing coronary heart disease risk improves shared decision making on statin therapy

A post-hoc analysis of a randomized study found that intermediate-risk participants who had a family history of coronary heart disease and received a genetic risk score were more likely to take statins.

Lead researcher Maya S. Safarova, MD, PhD, of the Mayo Clinic, and colleagues published their results online in JAMA Cardiology on April 13.

“To our knowledge, this study is the first to demonstrate that discussion of risk associated with a family history of [coronary heart disease] influences shared decision making regarding statin treatment in intermediate-risk individuals,” they wrote. Among participants with a family history of [coronary heart disease], disclosure of a [genetic risk score] was associated with a greater initiation of statins than was disclosure of a [Framingham risk score] alone, suggesting that quantitative genetic risk information additionally influences shared decision making regarding statin therapy.”

Previous research found a family history of coronary heart disease was associated with an estimated 1.5- to 2-fold high risk of coronary heart disease independent of conventional risk factors, according to the researchers.

For this analysis, they evaluated the MI-GENES (Myocardial Infarction-GENES) study, which enrolled residents of Olmsted County, Minn., who were at intermediate risk for coronary heart disease and had not received statin therapy. The residents enrolled between Oct. 9, 2013, and April 28, 2014, and were randomized in a 1:1 ratio to a conventional risk score (the Framingham risk score) alone or the Framingham risk score with a multilocus genetic risk score.

The researchers defined family history as a the presence of angina, MI or myocardial revascularization in a first-degree male or female relative (parents, siblings and children) before 55 or 65 years old, respectively. They calculated a genetic risk score based on genotypes at 28 coronary heart disease susceptibility loci.

A genetic counselor told participants that they had an increased risk of coronary heart disease if a relative had coronary heart disease. A physician then discussed shared decision making regarding statin therapy.

After three and six months, participants received assessments on their low-density lipoprotein cholesterol levels, statin use, dietary fat consumption and physical activity levels.

At baseline, the groups had similar characteristics. The mean age was approximately 59 years old, and approximately 48 percent of participants were males.

The researchers said the genetic risk score and Framingham risk score were higher in participants with a family history of coronary heart disease. However, the two measures were not correlated.

In addition, 47.3 percent of participants with a family history of coronary heart disease began statin therapy compared with 28.4 percent of participants without a family history of coronary heart disease. Of the participants who received a genetic risk score, 64.0 percent of participants with a family history of coronary heart disease and 33.3 percent of participants without a family history of coronary heart disease received statin therapy.

Further, of the participants with a family history of coronary heart disease, 64.0 percent of participants in the genetic risk score group and 33.3 percent of participants in the Framingham risk score group received statin prescriptions.

“The [genetic risk score] was not significantly higher in participants with a family history of [coronary heart disease], suggesting that family history and a [genetic risk score] may provide additive [coronary heart disease] risk information,” they wrote. “Additional studies are needed to investigate whether disclosing risk associated with family history leads to greater adherence to treatment and improved outcomes.”