The Role of the Retrograde Approach in Percutaneous Coronary Interventions for Chronic Total Occlusions : Insights from the Japanese Retrograde Summit Registry

Background: Percutaneous coronary intervention for chronic total occlusion (CTO-PCI) success rates have increased with adoption of the retrograde approach. We evaluated the role of the retrograde approach in CTO-PCI from the analysis of the Japanese Retrograde Summit Registry. Methods and Findings: We analysed 3,229 consecutive PCIs in 56 Japanese centres and included in this registry in January 2012–December 2013. We analysed background characteristics and procedure outcomes of the following groups: A, succeeded using only the antegrade approach; R, succeeded using the retrograde approach; RA, succeeded using the antegrade approach after failure of the retrograde approach; F, failed. Success in initial approach was obtained in 2,854 procedures (88.4%). Procedure numbers and rates in each group were: A, n=2,016 (62.4%); R, n=658 (20.4%); RA, n=180, 5.6%); Group F, n=375 (11.6%). J-CTO scores were 1.24 ± 0.95, 2.16±1.06, 1.69±1.04, and 2.00±1.07, respectively (p<0.0001). Average procedure time was >180 minutes and average air kerma >5 Gy. Overall in-hospital MACCE rate was 0.53%, and was high in Groups R and F (P<0.0001). Conclusions: Procedure success was achieved using only the antegrade approach in many cases. The retrograde approach succeeded even in difficult CTO-PCI cases. Limitations included large amounts of contrast agent, high-dose fluoroscopy, and high complication rate. Therefore, further developments are still required.