In the first-in-man SPIRIT First clinical trial, XIENCE V showed a significant benefit over the bare metal VISION stent. Compared with late loss of 0.85 ± 0.36mm in the VISION arm, XIENCE V reduced late loss by 88% (0.10 ± 0.23mm). Also the clinical safety of XIENCE V was confirmed with a 6-month MACE rate of 7.7%. In the SPIRIT II clinical trial, which compared the efficacy and safety of the XIENCE V stent versus the TAXUS PECSS stent, the primary endpoint was met showing a non-inferiority of the XIENCE V compared with the TAXUS regarding in-stent late loss at 180 days. Actually, XIENCE V was superior to TAXUS and reduced in-stent late loss by 72% from a mean of 0.36 mm to 0.11 mm. In addition, analysis of other key clinical endpoints showed a lower rate of ischemia driven MACE (2.7% vs. 6.5% for XIENCE V vs. TAXUS) and protocol-defined stent thrombosis (0.5% vs. 1.3% for XIENCE V vs. TAXUS). The lower rate of ischemia driven MACE at 180 days was sustained through 1 year and there were no new instances of late stent thrombosis in either group up to 1 year.