A sub-study of the PLATO trial showed that ticagrelor, which is currently under development, was effective at reducing acute coronary syndromes (ACS) in patients with genetic polymorphisms which cause a poor response to conventional drugs.
The study, published in The Lancet, suggests treatment with ticagrelor would mean more patients could receive access to effective treatment.
However, about 10-15% of patients have genetic variations in the genes CYP2C19 and ABCB1, which can cause patients to suffer a poor response to clopidogrel.
A blood test to screen for the genetic polymorphisms would identify those who may respond poorly to treatment, but is often unavailable in UK primary care.
Researchers used data from 10,285 patients who were part of the PLATO trial and agreed to genetic testing.
The primary outcome was a composite of cardiovascular death, MI, or stroke, with 12 months follow-up.
Among patients with the any loss-of-function genotype, ACS occurred less often with ticagrelor than clopidogrel.
However, in patients without a loss-of-function allele there was no difference in efficacy between the two drugs.