Background: The procedural success remains the major limiting factor for percutaneous coronary intervention (PCI) of chronic total occlusion (CTO). Recently, retrograde approach through collateral channels has been introduced to recanalize complex CTOs. Here we describe the procedural outcome of retrograde strategy for CTO PCI according to the experience of institutes and .

Methods: We studied procedural data of 84 consecutive CTO PCI cases performed using retrograde approach from 2006 to 2010, and enrolled in e-CTO multicenter registry.

Results: The overall procedural success rate of retrogradely attempted PCI was 66.7% (56/84). There was no difference of procedural success between institutes performed 1 to 10 cases and > 10 cases (68.8% (22/32) vs. 65.4% (34/52), p=NS). The procedural success also did not changed according to the time period (2006 to 2007, 71.4%, (20/28); 2008, 73.7% (14/19), 2009, 57.7% (15/26); 2010, 63.6% (7/11), p=NS). Pre-procedural CT also did not affect the procedural success (61.5% (16/26) vs. 69.0% (40/58), p=NS).

Conclusions: In our multicenter CTO PCI registry, the procedural success rate of CTO PCI using retrograde approach was moderate. Furthermore, the improvement of success rate according to the procedural volume or year, which might reflect temporal changes in practice pattern, was not seen. Dedicated retrograde operators would be required to improve the procedural success of complex CTO PCI.