A new study by a team from Canada and the US, has found that heart attack victims, who give up taking statins afterwards, double their risk of dying in the next year.
The findings of the study suggest that even though the pills may appear to have failed to prevent a heart attack, it is much better to go on taking them anyway.
In the study, researchers used data from the UK General Practice Research Database to assess the effects of statins - drugs that lower cholesterol levels - in patients who survived heart attacks and were still alive three months later.
Their study showed that the minority of patients who gave up statins after a heart attack were 88 per cent more likely to die in the next year than patients who had never used statins.
The researchers also found that those who had taken statins before the heart attack, and continued to take them afterwards, were 16 per cent less likely to die than those who had never used them.
The study reinforces suspicions that giving up statins has a "rebound" effect that actually increases risk for a while.
This may be because statins have effects that go beyond the reduction in cholesterol levels, and include a reduction in inflammation which is rapidly reversed when people stop taking them.
Regardless of the actual mechanism, researchers suggest that doctors should be careful to keep patients who have had heart attacks on statins.
Dr Stella Daskalopoulou of McGill University in Montreal and colleagues gave an alternative explanation.
They said that those who died were much more ill and stopped taking statins because their health was so precarious.
However, researchers suggested that 'Statin use should only be withdrawn under judicious clinical supervision.'
The study is published in the European Heart Journal.