French doctors are flagging a likely association between recreational drugs and cardiac problems.

Writing up their findings in Heart, a British Medical Journal publication, the researchers said substances such as cannabis, opioids, cocaine, amphetamines and ecstasy were detected in one in 10 cardiac intensive care patients admitted to 39 French hospitals over a two-week period.

“Compared with other non-using heart patients, users were more likely to die or to require emergency intervention for events such as cardiac arrest or acute circulatory failure,” the medics warned.

They found only half of all patients whose urine samples suggested they had taken drugs actually admitted to it.

A third of the patients younger than 40 had taken drugs, the tests suggested, while 25% of all drug-using patients had dabbled in more than one substance.

In a separate paper, doctors from London’s St Bartholomew’s Hospital and Queen Mary’s University of London said a bigger study would be needed to establish a “causal relationship” between recreational drug use and cardiac conditions.

But they said if doctors knew a patient had used recreational drugs, it “might shed light on the cause of their condition and inform how it’s managed” as well as offering “an opportunity for counselling about the adverse medical, psychological, and social effects of drugs.”

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