Myocardial infarction and patent coronary arteries - an uneventful association?

Abstract

Background: Although many studies addressed the issue of the occurrence of acute myocardial infarction (MI) in patients with angiographically patent coronary arteries, controversies exist concerning the pathophysiology and clinical outcome in this syndrome.
Aim: To evaluate the clinical course of patients with MI and patent coronary arteries as well as to assess the post-infarction short-term prognosis.
Methods: A retrospective analysis of patients with acute MI admitted to our institution over a period of 8 years (1995-2002) was performed. The study group consisted of 62 patients with MI and angiographically patent coronary arteries, examined within the first 30 days after the infarction, and the age and gender-matched control group of 62 patients with acute MI and significant coronary artery stenoses.
Results: Cardiovascular risk factors found in the study group versus the control group were: smoking 47 (66.1%) vs 54 (87.1%) patients (NS); dyslipidemia 18 (29.0%) vs 44 (74.2%) patients (p<0.005), and family history of coronary artery disease 16 (25.8%) vs 37 (61.3%) patients (p<0.05). The post-infarction complications were: ischaemic recurrences in 25 (40.3%) vs 46 (74.2%) patients (p<0.05); heart failure in 11 (17.7%) vs 26 (41.9%) patients (p<0.05); mechanical events in 12 (19.4%) vs 16 (25.8%) patients (NS); arrhythmias in 18 (29.0%) vs 12 (19.4%) patients (NS); peripheral thromboembolic complications in 5 (8.1%) vs 2 (3.2%) patients (NS), respectively.
Conclusions: In the population with MI and patent coronary arteries, smoking was the only well represented risk factor. Although there was a significantly lower incidence of ischaemic events and heart failure after MI in patients with patent rather than stenotic coronary arteries, the mechanical, arrhythmic and thromboembolic complications occurred with the same frequency.