TCT-436 Association of Myocardial Bridge and Acetylcholine Dose Response in Patients with Vasospastic Angina

• Sung Il Im¹, 
• Seung-Woon Rha¹, 
• Byoung Geol Choi¹, 
• Se Yeon Choi¹, 
• Sun Won Kim¹, 
• Jin Oh Na¹, 
• Seong Woo Han¹, 
• Cheol Ung Choi¹, 
• Hong Euy Lim¹, 
• Jin Won Kim¹, 
• Eung Ju Kim¹, 
• Chang Gyu Park¹, 
• Hong Seog Seo¹, 
• Dong Joo Oh¹

• ¹ Cardiovascular Center, Korea University Guro Hospital, Seoul, Korea, Republic of

Background

It is well known that myocardial bridge (MB) is a risk factor of vasospastic angina. But, clinical significance and angiographic characteristics of patients (pts) with both (+) acetylcholine (Ach) provocation test results and MB according to Ach dose are not clarified yet.

Methods

A total 3034 consecutive pts underwent coronary angiography with intracoronary Ach provocation tests were enrolled for this study. Ach was injected by incremental doses of 20, 50, 100μg into the left coronary artery. Significant coronary artery spasm (CAS) was defined as focal or diffuse severe transient luminal narrowing (>70%) with/without chest pain or ST-T change on ECG. A total 483 pts (15.9%) had both MB with vasospasm. We compared the clinical and angiographic characteristics, and clinical outcomes of (+) provocation pts with MB according to Ach dose (20, 50, 100μg).

Results

The baseline clinical and procedural characteristics are well balanced among the three groups. There was no difference in the incidence of chest pain, ischemic EKG change and AV block in 3 groups. But, the pts with Low Ach dose group (20μg) was associated with higher incidence of baseline spasm, severe vasospasm, more diffuse spasms (>30mm) than those with the High dose group (50,100μg). The incidence of 12-month mortality and recurrent chest pain were higher in the Low Ach dose group (20μg, Table).

Conclusions

The pts with MB significantly responded to low Ach dose were also associated with more diffuse, severe and basal spasm than pts respond to high dose consistent with those without myocardial bridge and 12-month mortality and recurrent chest pain were higher incidence in Low Ach dose group (20μg), suggesting more intensive medical therapy with close clinical follow up will be required for these patients.

Copyright © 2012 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.