To evaluate safety of reduction of dual antiplatelet therapy period to three months after implantation of Ultimaster sirolimus-eluting stent (U-SES).

Additionally to investigate appropriateness of thienopyridine monotherapy with discontinuation of aspirin.

Inclusion Criteria:

• Patients with coronary artery lesion who received percutaneous coronary intervention using Ultimaster sirolimus-eluting stent.
• Patients considered appropriate to discontinue dual antiplatelet therapy at 3 months after stent implantation.
• Patients who have provided written informed consent.

Exclusion Criteria:

• Patients previously experienced stent thrombosis.
• Patients who are unable to clinical follow-up procedure specified in the protocal for the present study.
• Patients who are enrolled or planned to participate in another clinical trials of antiplatelet therapy.

The present study consisted of the following two study arms: the 3-month DAPT arm, a new registry arm in which 1,500 patients are consecutively recruite at 72 medical institutions; and the Longer DAPT arm, a historical control arm that consisted of 1,123 patients at 58 medical institutions.