Scripps Health is saying it is the first U.S. hospital network to bring its heart care into the world of genetic medicine by offering a test to determine which stent patients may benefit from anti-platelet drug therapy, and which ones won't.
The Scripps announcement follows the Journal of the American Medical Association's August publication of a study that found "compelling evidence" that people with gene mutations, CYP2C19•2, have a poorer response to treatment with clopidogrel (Plavix) than people without the mutation.
While the genotype accounted for approximately 12% of the variation in clopidogrel response, the authors wrote, "with age, BMI and lipid levels, approximately 22% of the variation in clopidogrel response can be explained."
The drug is the second-most commonly prescribed in the U.S. and is commonly given to one million patients a year after they undergo coronary stent procedures.
"Patients who have the reduced function allele have a 50% higher risk of having a cardiovascular event" because of lack of response to clopidogrel, says Matthew Price, MD, director of the cardiac catheterization lab at Scripps Green Hospital in La Jolla, CA.
The four undesirable gene mutations the test will look for occur in 30% of people of European descent and in more than 40% of those with African or Asian ancestry.
In collaboration with Quest Diagnostics, which offers a saliva version of the test, Scripps is offering the screening test for the mutations just to Scripps Clinic patients, who are scheduled for elective stent procedures at the Scripps Green Hospital next door. Price expects about 70 to 100 of the 250 patients who undergo angiography each month will be offered the test, and most will agree.
Price says Scripps Green performs approximately 1,800 elective stent procedures annually, of which 70% are elective. The genetic tests will be made available to all elective stent patients, though some may not be candidates for alternate therapies for various reasons.
"This represents a landmark program in individualized medicine based on considerable new data and new choices for one of the most commonly prescribed medications and medical procedures in the world," cardiologist Eric Topol, MD, chief academic officer of Scripps Health, said in a statement. "This program demonstrates Scripps Health's commitment to being at the forefront of individualized cardiovascular medicine."
It is expected that the majority of insurance providers will pay for the test if the patient is scheduled for angiography with the possibility of stent insertion (less copayments or deductibles). However, Medicare, which pays $200 for the test, will be billed for those beneficiaries, according to a Quest spokeswoman.
Patients at other Scripps system hospitals may be offered the test as the program gets off the ground, Price says.
For those patients found to have the mutation, knowledge will enable different forms of treatment to overcome their resistance to clopidogrel, Price says. Some patients with weak response to the drug will get more of the drug, while others may be given other drugs, such as prasugrel or cilostazol.