IMPACT OF INCREASED BASAL TONICITY OF CORONARY ARTERY ON ACETYLCHOLINE PROVOCATION TEST RESULT IN KOREAN PATIENT WITH CHEST PAIN

• Sunwon Kim, 
• Seung-Woon Rha, 
• Amro Elnagar, 
• Byoung Geol Choi, 
• sung il Im, 
• Jin Oh Na, 
• Seongwoo Han,
• Cheol Ung Choi, 
• Hong Euy Lim, 
• Jin Won Kim, 
• Eung Ju Kim, 
• Hong-Seog Seo, 
• Chang Gyu Park, 
• Dong Joo Oh

• Cardiovascular Center, Korea University Guro Hospital, Seoul, South Korea

Background

Intracoronary (IC) nitroglycerine (NTG) infusion often induce modest vasodilation in arteries without significant vasoconstriction at provocation test. We designated this phenomenon as ‘baseline spasm’, and investigated the characteristics and clinical meaning of it.

Methods

Acetylcholine (Ach) provocation test was performed with incremental dosage (20, 50, 100μg). Vasoconstriction more than 70% was considered to be positive. A total of 1764 patients (pts) were grouped according to existence of baseline coronary spasm which was defined as diffuse coronary vasodilation more than 30% after IC NTG infusion when compared to initial angiography.

Results

There were no significant differences in baseline characteristics between 2 groups except alcohol consumption history. There was a trend toward greater use of CCB in baseline spasm group. Baseline spasm group had higher incidence of positive provocation test result, multi-vessel involvement, and chest pain during the test. By QCA analysis, pts with baseline spasm had higher incidence of significant vasoconstriction (> 70%) at lower dose of IC Ach. There was a tendency toward higher incidence of myocardial bridge in baseline spasm group.

Conclusion

According to our study, baseline spasm was considered as an important prognostic factor of positive Ach provocation test, an indicator of hyperreactivity of coronary artery to Ach, which represents severe endothelial dysfunction.

Copyright © 2012 Published by Elsevier Inc. All rights reserved.