Procedural failure of chronic total occlusion percutaneous coronary intervention: Insights from a multicenter US registry

Background The hybrid approach to chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has significantly increased procedural success rates, yet some cases still fail. We sought to evaluate the causes of failure in a contemporary CTO PCI registry. Methods We examined 380 consecutive patients who underwent CTO-PCI at 4 high volume CTO PCI centers in the United States using the "hybrid" approach. Clinical, angiographic, complication, and efficiency outcomes were compared between successful and failed cases. Failed cases were individually reviewed by an independent reviewer to determine the cause of failure. Results Procedural success was 91.3%. Compared with patients in whom CTO PCI was successful, those in whom CTO PCI failed had similar baseline clinical characteristics, but were more likely to have longer occlusion length, more tortuosity, more proximal cap ambiguity and blunt stump, and higher mean J-CTO scores (2.8±1.1 vs. 3.5±1.0, P<0.001), and less likely to have collaterals suitable for the retrograde approach (66% vs. 45%, P=0.021). Failure was due to a complication in 10 cases (30%). In the remaining 23 cases (70%) failure was due to inability to wire the lesion (n=21, 4 of which were CTOs due to in-stent restenosis), or poor antegrade flow after PCI (n=5). Conclusions Compared with successful cases, failed CTO-PCI cases are more likely to have higher J-CTO scores, longer occlusion length, ambiguous proximal cap and no appropriate collaterals for retrograde crossing. Development of novel CTO crossing techniques is needed to further increase CTO PCI success rates.