Consumers considering whether to purchase genetic testing services from companies that claim an ability to evaluate their "heart health" ought to put their money toward more reliable cardiovascular disease risk assessors, according to the Evaluation of Genomic Applications in Practice and Prevention Working Group. In its recently published recommendations, the working group says there is "insufficient evidence to recommend testing … genes to assess risk for cardiovascular disease" and that the "net health benefit from use of any of these tests alone or in combination is negligible."
The working group conducted a systematic, evidence-based review of genetic tests that assess cardiovascular disease risk — as outlined in a December Genomics in Medicine paper. The group considered the analytic validity, clinical validity, and clinical utility of seven screens on the market. Member Ned Calonge says the group sought to weigh potential health benefits against possible harms. "At the very least, we wanted to show that these tests do some good," says Calonge, chief medical officer of the Colorado Department of Public Health and Environment. "But on the other end, we also wanted to make sure there are no untoward outcomes of the tests, and that we'd considered those as well."
Cardiovascular disease risk is typically evaluated on the basis of blood pressure, cholesterol levels, and other traditional factors that showed significant correlations with health outcomes in the Framingham Heart Study. New assessment strategies are generally stacked up against this established approach. "We're always comparing cardiac risk strategies back to: 'Is this an improvement over Framingham?'" Calonge says.
Beyond SNPs at 9p21 — for which it found "convincing evidence" of an association with one's risk of heart disease, though not stroke — the EGAPP Working Group reports small cardiovascular disease risk associations for the other variants included in the tests it examined. "Other than one gene, 9p21, the combination of all the other genes gave a negligible increased risk, so it was hard for us to imagine how that would ever be beneficial," Calonge says.
Analytical validity data for many tests was hard to come by, the group also found. While there is a "proprietary nature" to the tests, Calonge says, this lack of information creates a research gap and a "black box" for the consumer.
Despite these findings, Calonge says there is "not sufficient evidence to close the door on this testing." Gene sets with greater predictive power could still be identified, or these panels could be useful for cardiovascular disease "outside of the risk arena," he adds.
When it comes to genetic testing for cardiovascular disease risk, "it's not that there's evidence of no benefit, it's that there's no evidence of benefit," Calonge says. "Those are very different things."