Acute myocardial infarction preceded by potential triggering activities: Angiographic and clinical characteristics

Background: In an investigation of the relationship between myocardial infarction (MI) preceded by certain activities or events and coronary angiographic data, including the extent of atherothrombotic involvement during acute MI, we hypothesized that when comparing patients with MI that was preceded by potential triggering activities (PTA "+") to MI without PTA, the former might have a distinct pathogenic basis exhibiting different angiographic and clinical features. Methods: In the framework of a national survey on acute coronary syndromes conducted during a 2-month period in 2002, 662 acute MI patients with complete angiographic data were divided into two groups, according to whether or not they reported the presence of specific unusual events or activities immediately preceding the onset of MI. Results: One hundred and one patients with PTA "+" MI were younger, and included a higher proportion of smokers than their counterparts (n = 561), who were characterized by a higher frequency of hypertension and diabetes. After adjustment for age, gender, prior MI or CABG, diabetes, hypertension, current smoking, serum creatinine level, left ventricular ejection fraction less than 30%, re-ischemia and Killip class II+, 30-day, 6 month and 1-year mortality was similar between the two groups. The incidence of LAD disease (P < 0.01), 3-vessel coronary disease (P < 0.03) and TIMI flow 0 or 1 after coronary angioplasty was significantly lower (P < 0.02) in patients with PTA "+" MI, while infarct-related right coronary artery (RCA) obstruction was significantly higher (OR: 1.7; 95% CI: 1.0-2.9). Conclusion: Further investigation is needed in order to confirm the association between angiographic data and potential triggering activities observed in our study, and to determine the mechanisms responsible for this finding.