According to a study, millions of people in the UK who take aspirin to reduce their chances of heart attack and stroke might actually benefit more from a different medication that costs under 4p daily.

Those diagnosed with coronary artery disease (CAD) are usually instructed to take aspirin daily to thin their blood, aiming to lower the likelihood of serious heart issues.

However, a significant new study shows that switching to the blood thinner clopidogrel could reduce the risk of heart-related incidents or death by an additional 14%.

Researchers from an international collaboration, which includes experts from Imperial College London, claim this alternative offers better protection and should be considered as the primary option in medical treatments.

Their findings were simultaneously published in The Lancet medical journal and presented at the European Society of Cardiology congress in Madrid.

Coronary artery disease, often referred to as coronary heart disease, is the most prevalent heart condition, affecting 2.3 million individuals in the UK.

It occurs when arteries in the heart become narrowed by a build-up of atheroma, a fatty material within their walls.

The pain or discomfort felt from such narrowing is called angina and if a blockage occurs it can cause a heart attack.

 Patients with CAD have traditionally been put on aspirin for the rest of their life but evidence supporting its long term benefits and safety have been limited.

Now researchers have analysed seven previous randomised trials involving 28,982 patients with CAD who had been taking clopidogrel or aspirin, known as antiplatelet medications.

After an average of 5.5 years, those on clopidogrel were 14 per cent less likely to have suffered a heart attack or stroke or to have died from a heart-related condition than those on aspirin.

The analysis drew from diverse patient groups, including those who had undergone procedures like stent placement or had experienced acute coronary syndrome.

It also examined various subgroups to ensure the findings applied broadly.

Notably, even patients who might respond less well to clopidogrel due to genetic or clinical factors still benefited from its use over aspirin.

And there was no statistically significant difference in rates of major bleeding, a known but rare side-effect of taking blood thinners.

Writing in The Lancet, the experts said: ‘This comprehensive synthesis of available evidence indicates that, in patients with CAD, long-term clopidogrel monotherapy offers superior protection against major cardiovascular and cerebrovascular events compared with aspirin, without an excess risk of bleeding.

 ‘The superior efficacy of clopidogrel versus aspirin was consistent across multiple key subgroups, including individuals with clinical features predictive of poor clopidogrel responsiveness, supporting the generalisability of these findings to the broad spectrum of patients with CAD.

‘These results support a preference for clopidogrel over aspirin for chronic antiplatelet monotherapy for patients with stable CAD.

‘The widespread availability, generic formulation, and affordability of clopidogrel further supports its potential for extensive adoption in clinical practice.’

The review identified 256 deaths or incidents of major bleeding in the clopidogrel group and 279 in the aspirin group, giving rates of 0.71 and 0.77 per 100 patient years, respectively.

However, the difference in these death and bleeding rates was not statistically significant.

The NHS drug tariff indicates a 28 pack of 75mg clopidogrel tablets, which are widely used to prevent blood clots, costs just £1.01 or 3.6p each.

The same size pack of 75mg aspirin tablets cost 69p or 2.5p each.

The authors say that because both medications are widely available, the study’s findings have the potential to influence clinical guidelines worldwide and improve patient outcomes.

 However, further research on the cost-effectiveness of clopidogrel, as well as broader population studies, is needed to support changes in treatment standards, they add.

Professor Bryan Williams, chief scientific and medical officer at the British Heart Foundation, said: ‘Aspirin is a commonly prescribed drug to help prevent repeat heart attacks and strokes.

‘This research suggests that clopidogrel, an alternative to aspirin, might be more effective at preventing recurrent heart attack or stroke.

‘Importantly, these benefits come without a greater risk of major bleeding.

‘These findings are likely to impact the medications doctors prescribe to their patients to reduce their risk of future heart problems.’