Background: A sizeable proportion of patients with primary stable microvascular angina (MVA; exercise-induced angina, positive exercise stress test [EST], normal coronary arteries) have recurrent symptoms during follow-up. There have been no previous studies, however, on the long-term results of EST and their correlation with symptom outcome.Methods and Results:Follow-up EST was performed in 71 MVA patients at an average of 16.2 years (range, 5-25 years) from the first EST. Angina status was assessed on weekly frequency of angina episodes and nitroglycerin consumption and by whether symptoms had worsened, improved, or remained unchanged over time. At follow-up EST, 41 patients (group 1) had exercise-induced ischemia, whereas 30 patients (group 2) had negative EST. Compared to group 2, group 1 patients more frequently had exercise-induced dyspnea, and had a greater maximum ST-segment depression and a lower coronary blood flow response to adenosine and cold pressor test, but group 2 patients had a more frequent history of rest angina. No differences between the 2 groups were found at follow-up in angina status or change in symptom status during follow-up.
Conclusions: Electrocardiogram results improve significantly in a sizeable proportion of patients with MVA. Changes in EST results, however, were not associated with clinical outcome.
Keywords: Clinical outcome; Exercise stress test; Follow-up; Microvascular angina.