Background: Trimetazidine (Vastinan짰) has been shown to have anti-ischemic properties however; this is a less well known anti-anginal drug that controls myocardial ischemia through intracellular metabolic changes by inhibiting 3-KAT. We clinically assessed the additional therapeutic value of trimetazidine at 6 months in patients (pts) with documented vasospastic angina who are under conventional antianginal medications. Methods: A total 158 pts (91 men, Age; 54.0짹11.5 years) without significant coronary stenosis underwent incremental intracoronary acetylcholine (Ach) provocation test (A1 to A3, 20, 50 and 100關g). Pts were randomly treated with trimetazidine 20mg bid combined with conventional antianginal medications including calcium antagonist, nitrate and/or nicorandil up to 6 months and discontinued if pts are completely angina-free state. Pts were classified as clinical success, recurrent and failure after discontinuation of medication at 6 to 8 months and the efficacy and safety of trimetazidine was evaluated according to the clinical outcomes at 6 months. Results: Baseline characteristics were not different between groups except hyperlipidemia (4.4% vs. 19.0% in non-trimetazidine group, p=0.03). Most pts received diltiazem (n=139), isosorbide dinitrate (n=58) and/or nicorandil (n=85) and mean number of medications for each pts were 2.18짹0.9. All the pts in the trimetazidine group were well tolerated without obvious side effects. Although the trimetazidine group appears to have better clinical outcomes numerically compared with the non-trimetazidine group at 6 months, there were no statistically significant differences between the two groups (Table). Conclusion: Trimetazidine was safe and seemed to improve clinical status at 6 months following conventional antianginal medication although it was not statistically significant. Large, long-term trials assessing the efficacy of trimetazidine comparing with or without conventional medications are required to establish the role of trimetazidine in clinical management of vasospastic angina.