Triggering of myocardial infarction by cocaine

Background-Cocaine has been implicated as a trigger of acute myocardial inf arction in patients with and those without underlying coronary atherosclero sis. However, the magnitude of the increase in risk of acute myocardial inf arction immediately after cocaine use remains unknown. Methods and Results-In the Determinants of Myocardial Infarction Onset Stud y, we interviewed 3946 patients (1282 women) with acute myocardial infarcti on an average of 4 days after infarction onset. Data were collected on the use of cocaine and other potential triggers of myocardial infarction. We co mpared the reported use of cocaine in the hour preceding the onset of myoca rdial infarction symptoms with its expected frequency by using self-matched control data based on the case-crossover study design. Of the 3946 patient s interviewed, 38 (1%) reported cocaine use in the prior year and 9 reporte d use within the 60 minutes preceding the onset of infarction symptoms. Com pared with nonusers, cocaine users were more likely to be male (87% vs 674, P = 0.01), current cigarette smokers (84% vs 32%, P<0.001), younger (44+/- 8 vs 61+/-13 years, P<0.001), and minority group members (63% vs 11%, P<0.0 01). The risk of myocardial infarction onset was elevated 23.7 times over b aseline (95% CI 8.5 to 66.3) in the 60 minutes after cocaine use. The eleva ted risk rapidly decreased thereafter. Conclusions-Cocaine use is associated with a large abrupt and transient inc rease in the risk of acute myocardial infarction in patients who are otherw ise at relatively low risk, This finding suggests that studying the pathoph ysiological changes produced by cocaine may provide insights into the mecha nisms by which myocardial infarction is triggered by other stressors.