Genetic variation could reduce the effectiveness of common heart medication among South Asians

People who have recently had a heart attack are often prescribed clopidogrel, a medication that decreases the risk of having another heart attack. While the drug is very effective at preventing subsequent heart attacks, it can only work if it’s activated by the body’s CYP2C19 enzyme. Certain genetic variations mean the body can’t activate clopidogrel, because it can’t make this enzyme.

An inability to activate clopidogrel is actually very common. An estimated one in three people of European ancestry has one of these genetic variants – and they are even more common in some ethnic groups.

For example, more than nine in every ten Indigenous people of the Pacific islands have one of these genetic variants. So, they probably have a greater risk of subsequent heart attack if prescribed clopidogrel. However, studies linking the genetic variants with real-world health data have not been done in many non-European populations.

Our new study has also shown that clopidogrel may not be effective for many British south Asians. This is significant, as south Asian people suffer from high rates of cardiovascular disease in the UK.

Genetic variants

We began our study by analysing data from 44,396 participants who’d participated in Genes & Health – a study of British-Pakistani and British-Bangladeshi people, which has linked genetic data with national records of health problems and prescriptions.

We found that nearly six in...

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