Background

There have been many studies about acetylcholine (Ach) induced coronary artery spasm (CAS). However, although basal CAS is common in clinical practice, clinical outcomes according to the response to Ach in patients with basal CAS areunknown.

Methods

A total of728 patients without significant coronary lesion who have visible CAS before Ach test were enrolled between November 2004 and October 2010. Patients were divided into two groups according to the response to the acetylcholinetest. (Ach responder group: n=495, Ach non-responder group: n=233).

Results

Baseline characteristics, laboratory findings and medication history of patients in the each group were matched using propensity score matching. ECG change during Ach test (ST segment change or T wave inversion) was more frequent in Ach responder group (p<0.001). There was no significant difference in mortality or major adverse cardiac & cerebrovascular events (MACE) between two groups. But Ach responder group showed significant higher rate of recurrent chest pain which needs re-evaluation of coronary artery.(OR; 3.05, 95%CI; 1.32-7.01, p=0.009). And this difference was significant after multivariate analysis of other cardiovascular risk factors (OR; 3.22, 95%CI; 1.43-7.27, p=0.005).

Conclusion

Ach responsive patients who have basal CAS was not associated with MACE, but associated with recurrent chest pain. Therefore, more intensive anti-spastic medication and close clinical follow up would be needed for this kind of patients.

Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.