SummarySame-day discharge transradial percutaneous coronary intervention (TRI) has been reported to be safe and feasible in Western countries. However, Asia has not produced any reports related to this matter. The present study explored the safety and feasibility of patients with indications for TR coronary angiography and ad hoc PCI with a same-day discharge protocol. Between October 1995 and December 2002, 660 adult patients were admitted to our hospital for ad hoc PCIs. Of these, 214 patients were discharged on the day of their PCI (group A), while the remaining 446 patients were referred for out-patient department (OPD) PCI with subsequent admission (group B). Periprocedural complications were not significantly different between the groups. There were no differences in 1-month major adverse cardiac events including death, myocardial infarction, and target vessel revascularization (1.4% versus 0.2% for groups A and B, respectively; P = 0.068). Three group A cases (1.4%) experienced peri-and post-PCI myocardial infarction and one group B case (0.2%) experienced a post-PCI myocardial infarction. No patient died or required emergency bypass surgery. In group A, 8 cases (3.7%) required cutting balloon angioplasty and 2 cases (0.9%) needed rotational atherectomy. TRI is safe and feasible on an outpatient basis. For select patients, even though PCI can carry the potential risk of subsequent cutting balloon angioplasty or rotational atherectomy, the procedure should still be considered. (Int Heart J 2010; 51: 371-376) Key words: Angioplasty, Out-patient, Transradial T he transradial (TR) approach for diagnostic coronary angiography was first reported in 1989, 1) and the use of TR percutaneous coronary intervention (PCI) was reported in 1992.2) The benefits of TR intervention (TRI) include less bleeding complications, 3) and earlier ambulation and better quality of care after the procedure. 4) Accordingly, TRI has been increasingly adopted for out-patient department (OPD) procedures, with same-day discharge, with a variety of studies including randomized trials verifying the safety and feasibility of the approach in Western countries. [5][6][7][12][13][14][15][16][17][18][19][20] Beginning in 1994, we and others introduced TRI in Asia. [8][9][10] However, feasibility and safety issues of OPD TRI without admission have not been reported in Asia. The present study was undertaken to explore the safety and feasibility of OPD patients with indications for TR coronary angiography and ad hoc PCIs, who fulfilled predefined criteria for same-day discharge after TRI. Consecutive patients after OPD TRIs were selected by operators and were divided into two groups (admission for close observation or without admission), and the clinical outcomes of the two groups were compared prospectively.