More than half of patients pres­cribed dual antiplatelet therapy for coronary artery disease remain on the drugs longer than the recommended 12 months, researchers have found in a Queensland cohort.

They also showed that, despite expectations that the burden of medical therapy would be reduced following stent insertion, this did not occur in practice.

The researchers examined the duration of dual antiplatelet therapy (DAPT) and annual pharmaceutical costs for 740 patients being treated with percutaneous coronary intervention with stent insertion, coronary artery bypass graft surgery or only medical therapy such as antiplatelets, lipid-lowering or antianginal drugs.

Most patients continued DAPT significantly longer than recommended — 31 months on average for those on medical therapy only, and 16 months for stent patients.