Retrograde chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is associated with lower success and higher complication rates when compared with the antegrade approach.BACKGROUNDRetrograde chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is associated with lower success and higher complication rates when compared with the antegrade approach.This study sought to assess contemporary techniques and outcomes of retrograde CTO PCI.OBJECTIVESThis study sought to assess contemporary techniques and outcomes of retrograde CTO PCI.We examined the baseline characteristics, procedural techniques and outcomes of 4,058 retrograde CTO PCIs performed at 44 centers between 2012 and 2023. Major adverse cardiac events (MACE) included any of the following in-hospital events: death, myocardial infarction, repeat target vessel revascularization, pericardiocentesis, cardiac surgery, and stroke.METHODSWe examined the baseline characteristics, procedural techniques and outcomes of 4,058 retrograde CTO PCIs performed at 44 centers between 2012 and 2023. Major adverse cardiac events (MACE) included any of the following in-hospital events: death, myocardial infarction, repeat target vessel revascularization, pericardiocentesis, cardiac surgery, and stroke.The average J-CTO (Multicenter CTO Registry in Japan) score was 3.1 ± 1.1. Retrograde crossing was successful in 60.5% and lesion crossing in 81.6% of cases. The collaterals pathways successfully used were septals in 62.0%, saphenous vein grafts in 17.4%, and epicardials in 19.1%. The technical and procedural success rates were 78.7% and 76.6%, respectively. When retrograde crossing failed, technical success was achieved in 50.3% of cases using the antegrade approach. In-hospital MACE was 3.5%. The clinical coronary perforation rate was 5.8%. The incidence of in-hospital MACE with retrograde true lumen crossing, just marker antegrade crossing, conventional reverse controlled antegrade and retrograde tracking (CART), contemporary reverse CART, extended reverse CART, guide-extension reverse CART, and CART was 2.1%, 0.8%, 5.5%, 3.0%, 2.1%, 3.2%, and 4.1%, respectively; P = 0.01).RESULTSThe average J-CTO (Multicenter CTO Registry in Japan) score was 3.1 ± 1.1. Retrograde crossing was successful in 60.5% and lesion crossing in 81.6% of cases. The collaterals pathways successfully used were septals in 62.0%, saphenous vein grafts in 17.4%, and epicardials in 19.1%. The technical and procedural success rates were 78.7% and 76.6%, respectively. When retrograde crossing failed, technical success was achieved in 50.3% of cases using the antegrade approach. In-hospital MACE was 3.5%. The clinical coronary perforation rate was 5.8%. The incidence of in-hospital MACE with retrograde true lumen crossing, just marker antegrade crossing, conventional reverse controlled antegrade and retrograde tracking (CART), contemporary reverse CART, extended reverse CART, guide-extension reverse CART, and CART was 2.1%, 0.8%, 5.5%, 3.0%, 2.1%, 3.2%, and 4.1%, respectively; P = 0.01).Retrograde CTO PCI is utilized in highly complex cases and yields moderate success rates with 5.8% perforation and 3.5% periprocedural MACE rates. Among retrograde crossing strategies, retrograde true lumen puncture was the safest. There is need for improvement of the efficacy and safety of retrograde CTO PCI.CONCLUSIONSRetrograde CTO PCI is utilized in highly complex cases and yields moderate success rates with 5.8% perforation and 3.5% periprocedural MACE rates. Among retrograde crossing strategies, retrograde true lumen puncture was the safest. There is need for improvement of the efficacy and safety of retrograde CTO PCI.