Technical and procedural outcomes of the retrograde approach to chronic total occlusion interventions

Aims: The retrograde approach is critical for achieving high success rates in chronic total occlusion (CTO) percutaneous coronary intervention (PCI), but has been associated with higher risk of complications. We examined the contemporary outcomes of the retrograde approach to CTO PCI aiming to identify areas in need of improvement. Methods and results: We compared the technical and procedural outcomes of retrograde (n=1,515) and antegrade-only CTO PCIs (n=2,686) in a contemporary multicentre CTO registry. The mean age of patients undergoing retrograde PCI was 65±10 years and 86% were men, with high prevalence of prior myocardial infarction (51%), prior PCI (71%), and coronary artery bypass graft surgery (45%). The mean J-CTO score (3±1 vs 2±1, p<0.001) was higher in retrograde PCIs. The most commonly used collateral channels were septals (65%), epicardials (32%), saphenous venous grafts (14%) and left internal mammary artery grafts (2%). Overall technical (79% vs 91%, p<0.001) and procedural (75% vs 90%, p<0.001) success rates were lower with the retrograde approach, and these patients had a higher rate of in-hospital major complications than antegrade-only PCI patients (5.1% vs 0.8%, p<0.001), due to higher mortality (1.1% vs 0.1%, p<0.001), acute myocardial infarction (1.9% vs 0.2%, p<0.001), repeat PCI (0.7% vs 0.1%, p=0.001), and pericardiocentesis (1.7% vs 0.3%, p<0.001). Conclusions: In summary, the retrograde approach to CTO PCI is performed in higher complexity lesions and is associated with lower success rates and a higher rate of major complications. Clinical Trial Registration: NCT02061436, Prospective Global Registry for the Study of Chronic Total Occlusion Intervention (PROGRESS-CTO).