Three Part Question
In [patients presenting with cocaine associated chest pain] what [is the incidence] of [acute myocardial infarction]?
A 32 year old man presents to the emergency department with central chest pain suggestive of cardiac ischaemia. He has had pain for 50 minutes after nasal cocaine. He is an occasional cocaine user who has not had chest pain previously. He is previously well. His 12 lead ECG is normal and he is now pain free. You see him in the resuscitation room and prescribe oral aspirin 300mg. He is cardiovascularly stable. You admit him and do a 12 hour troponin T, which is normal. The next day a colleague suggests that there was no need to admit as he was well, had a normal ECG, had few risk factors and that as cocaine causes spasm rather than clots he could have gone home. You wonder whether this is good advice.
Cochrane database and Medline 1966-12/02 using the OVID interface.
[exp cocaine OR exp cocaine-related disorders OR exp crack cocaine OR cocaine.mp] AND [exp Myocardial Infarction OR myocardial infarction.mp OR exp Chest Pain OR chest pain.mp] LIMIT to human, English AND abstracts.
No relevant papers found on Cochrane library. Altogether 198 papers were found on MEDLINE of which 8 were relevant to the 3 part question.
|Author, date and country
||Study type (level of evidence)
|Kossowsky WA et al,|
|19 patients presenting with chest pain shortly after intranasal, iv or smoking of cocaine||Prospective cohort study||Coronary angiogram||5 patients:|
4 normal coronary arteries
1 proximal stenosis of right coronary artery
Hospitalised patients only|
|Incidence of AMI||17 (89%) which demonstrate non-Q wave infarction|
2 with Q wave infarction
|Amin M et al,|
70 patients with cocaine associated chest pain
||Retrospective cohort study||Specificity of ECG||60%||Small study
Hospitalised patients only
|Incidence of AMI||22/70 (31%)|
|Sensitivity of ECG||91%|
|Zimmerman JL et al,|
|48 admitted patients with cocaine associated chest pain||Retrospective case note review||Incidence of AMI||3/48 (6%)||Wide distribution of time between use and presentation
Not ED patients
|Number of patients with ECG criteria for thrombolysis||18/48 (37%)|
|Gitter MJ et al,|
|101 admitted patients with cocaine associated chest pain
||Prospective cohort study||Incidence of AMI||No patients had AMI confirmed||Poor gold standard used. CK rises or CKMB fractions
|Number of patients with ECG criteria for thrombolysis||8 (8%)|
|Hollander JE et al,|
|246 patients presenting with cocaine associated chest pain in 6 US centres
||Prospective cohort study||PPV of ECG for AMI||96%||Gold standard was a 2 fold rise in CKMB
Not consecutive enrolment of patients
|Specificity of ECG for AMI||90%|
|PPV of ECG for AMI||18%|
|Sensitivity of ECG for AMI||36%|
|Incidence of AMI||14/246 (6%)|
|Mittleman MA et al,|
|Interviewed 3946 patients with AMI (an average of 4 days after infarction onset)
||Case cross-over study||38 (1%) reported cocaine use in the prior year. 9 reported cocaine use within the 60 minutes preceding the onset of infarction||The users of cocaine sustained a transient 24-fold increase in risk of MI in the hour immediately after cocaine use and that the elevated risk rapidly decreased thereafter||Data based on patient self-report
Small number of exposed cases
The absolute risk of MI onset cannot be directly estimated from the data|
|Weber JE et al,|
|250 patients presenting with cocaine associated chest pain in 29 US centres AMI diagnosed on WHO criteria||Prospective cohort study||Number without ECG changes who had confirmed infarction||2/67 had confirmed AMI||Wide distribution of time between use and presentation (up to 7 days)
6% had no urinary metabolites
Gold standard was a 2 fold rise in CKMB
Most (91%) patients used crack cocaine
|Number with ECG changes compatible with infarction||9/250 of which all had confirmed AMI|
|Incidence of AMI||15/250 (6%)|
|Number with ECG changes compatible with ischaemia||39/250 of which 4 had confirmed AMI|
|Feldman JA et al,|
|293 patients with cocaine associated chest pain. Sub study of the Aci-TIPI trial
||Prospective cohort study||Incidence of AMI||(0.7%) CI 0.08-2.4% with cocaine||Sub study of another trial.
WHO criteria for AMI
Wide variation of AMI incidence between hospitals
|Incidence of ACS||1.4% CI 0.37-3.5%|
The incidence of AMI in cocaine associated chest pain is small but significant. The ECG appears to have a higher false positive rate in these patients. A normal ECG reduces but does not exclude myocardial damage. Most AMI patients will present with ST elevation or an abnormal ECG. Many of the above papers exhibit selection bias as only admitted patients are used, this may account for some of the higher incidences recorded. They also enrol patients who have taken cocaine hours before symptomatology, this contradicts the known pharmacology of cocaine. Early presentation following cocaine use would normally be expected. It must be remembered that some of the reported incidence will be co-incidental. Those patients presenting with normal findings, and a normal ECG have a low but not absent AMI risk. They should have myocardial damage excluded.
Clinical Bottom Line
Acute myocardial infarction should be excluded using cardiac markers in patients presenting to the emergency department with cocaine related chest pain.
- Kossowsky WA, Lyon AF, Chou SY. Acute non-wave cocaine-related myocardial infarction. Chest 1989;96(3):617-21.
- Amin M, Gabelman G, Karpel J, et al. Acute myocardial infarction and chest pain syndromes after cocaine use. Am J Cardiol 1990;66(20):1434-7.
- Zimmerman JL, Dellinger RP, Majid PA. Cocaine-associated chest pain. Ann Emerg Med 1991;20(6):611-5.
- Gitter MJ, Goldsmith SR, Dunbar DN, et al. Cocaine and chest pain: clinical features and outcome of patients hospitalized to rule out myocardial infarction. Ann Intern Med 1991;115(4):277-82.
- Hollander JE, Hoffman RS, Gennis P, et al. Prospective multicenter evaluation of cocaine-associated chest pain. Cocaine Associated Chest Pain (COCHPA) Study Group. Acad Emerg Med 1994;1(4):330-9.
- Mittleman MA, Mintzer D, Maclure M et al. Triggering of myocardial infarction by cocaine. Circulation 2000;99(21):2737-41.
- Weber JE, Chudnofsky CR, Boczar M, et al. Cocaine-associated chest pain: how common is myocardial infarction? Acad Emerg Med 2000;7(8):873-7.
- Feldman JA, Fish SS, Beshansky JR, et al. Acute cardiac ischemia in patients with cocaine-associated complaints: results of a multicenter trial. Ann Emerg Med 2000;36(5):469-76.