Long-term follow-up of patients with mild coronary artery disease and endothelial dysfunction

Background-Coronary endothelial dysfunction is characterized by vasoconstri ctive response to the endothelium-dependent vasodilator acetylcholine. Alth ough endothelial dysfunction is considered an early phase of coronary ather osclerosis, there is a paucity of information regarding the outcome of thes e patients. Thus, this study was designed to evaluate the outcome of patien ts with mild coronary artery disease on the basis of their endothelial func tion. Methods and Results-Follow-up was obtained in 157 patients with mildly dise ased coronary arteries who had undergone coronary vascular reactivity evalu ation by graded administration of intracoronary acetylcholine, adenosine, a nd nitroglycerin and intracoronary ultrasound at the time of diagnostic stu dy. Patients were divided on the basis of their response to acetylcholine i nto 3 groups: group 1 (n = 83), patients with normal endothelial function; group 2 (n = 32), patients with mild endothelial dysfunction; and group 3 ( n = 42), patients with severe endothelial dysfunction. Over an average 28-m onth follow-up (range, 11 to 52 months), none of the patients from group 1 or 2 had cardiac events. However, 6 (14%) with severe endothelial dysfuncti on had 10 cardiac events (P<0.05 versus groups 1 and 2). Cardiac events inc luded myocardial infarction, percutaneous or surgical coronary revasculariz ation, and/or cardiac death. Conclusions-Severe endothelial dysfunction in the absence of obstructive co ronary artery disease is associated with increased cardiac events. This stu dy supports the concept that coronary endothelial dysfunction may play a ro le in the progression of coronary atherosclerosis.