In a bid to improve management of patients who present with chest pain and other heart attack symptoms, the American Heart Association (AHA) has issued a scientific statement recommending doctors ask about cocaine use when they examine younger patients with chest pains and who have no obvious risk factors for heart disease.
The statement is published as a paper in an early online issue of Circulation, the journal of the AHA, and is authored by Dr James McCord, chair of the statement writing committee and cardiology director of the chest pain unit for the Henry Ford Medical System in Detroit, Michigan, and colleagues.
McCord explained that if doctors suspect a heart attack, then they should rule out cocaine use early on because cocaine exposure changes what is safe and what is not. The statement emphasizes in particular that:
- Clot-busters and beta-blockers are dangerous for patients who have been exposed to cocaine.
- Bare metal stents rather than drug-eluting stents should be used in long-term cocaine users.
- Most cocaine-associated chest pain is not a heart attack.
- Patients who have been exposed to cocaine should be placed under observation for 9 to 12 hours.
Assessment of cocaine use is particularly important for younger patients, said McCord. 37 per cent of all cocaine-related visits to emergency departments are by people aged between 35 and 44 years, he added.
Research shows that chest pain that is associated with cocaine use tends to appear within three hours of taking the drug, but the chemical residue stays in the body for a minimum of 18 hours and can continue to present problems, said McCord. Also, doctors have more difficulty diagnosing heart attacks using electrocardiographs of younger patients, he explained.
Cocaine-associated emergency department visits went up by 47 per cent between 1999 and 2002, said the authors, which means that the number of cocaine users that doctors are likely to come across as a result of such admissions will probably increase.
A common method for diagnosing and treating heart attacks is to take the patient into the catheterization lab (the “cath lab”), which has the equipment that allows the doctor to insert a thin tube or catheter into a heart artery and then use imaging techniques to see where the blockage might be, and then inflate a small balloon to open the the artery.
Where a cath lab is not available, a doctor may give a patient who appears to have had a heart attack a clot busting drug instead. However, if the patient is a recent cocaine user there is an added risk of bleeding into the brain because of the higher blood pressure induced by the cocaine. So this procedure should only be used if the doctor is absolutely certain the patient has indeed had a heart attack, said the authors.
Beta-blockers are used to reduce blood pressure without causing narrowing of the arteries. But in patients who have recently been using cocaine and who present with chest pain, beta-blockers may actually produce the opposite effect: they could increase blood pressure and make the arteries already narrowed by cocaine even narrower. This has been shown to have potential fatal consequences in studies using animals, said McCord.
Drug eluting or bare metal stents are used to restore blood flow to the heart where there is no arterial blockage. Studies have shown that long term cocaine users fitted with stents have a tendency to lapses in taking the regular medication needed to stop drug-eluting stents becoming blocked, and that is why the statement recommends such patients be fitted with bare metal ones only.
Cocaine can worsen the effects of a heart attack, said the authors, because it increases the heart’s need for oxygen, elevating heart rate, blood pressure and contraction power at each beat. But at the same time the drug also constricts blood vessels and makes it harder for the heart to get the oxygen it needs. This increases risk of clotting and manifests as angina, which is felt as chest pain.
The statement draws attention to other conditions that can develop alongside chest pain and heart attacks with cocaine users, and it is important that these are also looked for as they can be crucial to the treatment that is followed. For instance, one condition that can accompany cocaine use is aortic dissection (a tear in a blood vessel that can be fatal), another is bleeding into the lung (“crack lung”).
Other symptoms that patients who use cocaine also report having alongside chest pains are shortness of breath, palpitations, feelings of anxiety, nausea, dizziness and sweating profusely. These are very similar to heart attack.
“Management of Cocaine-Associated Chest Pain and Myocardial Infarction. A Scientific Statement From the American Heart Association Acute Cardiac Care Committee of the Council on Clinical Cardiology.
James McCord, Hani Jneid, Judd E. Hollander, James A. de Lemos, Bojan Cercek, Priscilla Hsue, W. Brian Gibler, E. Magnus Ohman, Barbara Drew, George Philippides, and L. Kristin Newby.
Circulation, Published before print on March 17, 2008.
DOI:10.1161/CIRCULATIONAHA.107.188950
Sources: American Heart Association press statement.
Written by: Catharine Paddock, PhD