Backgrounds:?Coronary artery spasm has been identified as an alternative cause for myocardial infarction (AMI) in patients (pts). It has been shown about 50% of ACS pts without obstructive lesion had coronary spasm. However there is few data on the prognosis in these pts. Therefore we aimed to compare prognosis between pts with AMI due to coronary spasm without culprit lesion and AMI due to culprit lesion during 2 year of follow up.?Methods:?A total of 36,797 pts with AMI in the KAMIR (Korea Acute Myocardial Infarction Registry) were grouped according to AMI due to coronary spasm without culprit lesion (CAS MI; N=484) and AMI due to culprit lesion (Stenotic MI; N=36,313). We compared MACE defined as composite of cardiac death (CD), any myocardial infarction (MI), repeat revascularization (RR) at 2 year between the two groups. Results:?The incidence of MACE in pts with CAS MI at 2 follow up was significantly lower than in pts with Stenotic MI (10.8% vs 7.1%; log rank p=0.006). The pts with CAS MI had significantly lower incidence of RR (4.2% vs 0.4%; log rank p<0.001). However the incidence of MI (1.5% vs 0.9%; log rank p=0.594) and CD (5.4% vs 4.6%; log rank p=0.456) were similar between the two groups.?Conclusions:?In overall population with AMI, clinical outcomes of CAS MI was significantly lower than those of Stenotic MI upto 2 years, which is attributable to relatively low rate of RR. However the incidence of CD and MI in the pts with CAS MI could not be so small as compared with those of Stenotic MI.