Coronary artery dissection is a contraindication for the use of rotational atherectomy, since rotational atherectomy may propagate coronary dissection. In the presence of coronary dissection, conservative management is suggested for approximately 4 weeks to permit the dissection to heal prior to treatment with rotational atherectomy. However, a lot of patients have frequent angina attacks and some patients develop serious complications including abrupt vessel closure during this period. Thus, immediate strategies cope with coronary dissection induced by balloon dilation is needed for the early recovery of those patients. The present study was performed to compare the safety and efficacy of immediate RA and delayed RA in the treatment with nondilatable calcified lesion complicated by coronary dissection.