Document Type

Conference Proceeding

Publication Date


Publication Title

J Am Coll Cardiol


Background: The impact of proximal cap ambiguity on procedural techniques and outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has received limited study.

Methods: We examined the clinical and angiographic characteristics and procedural outcomes of 11,169 CTO PCIs performed in 10,932 patients at 42 US and non-US centers between 2012 and 2022.

Results: Proximal cap ambiguity was present in 35% of CTO lesions. Patients whose lesions had proximal cap ambiguity were more likely to have had prior PCI (65% vs 59%; P < 0.01) and prior coronary artery bypass graft surgery (37% vs 24%; P < 0.01). Lesions with proximal cap ambiguity were more complex with higher J-CTO score (3.1 ± 1.0 vs 2.0 ± 1.2; P < 0.01) and lower technical (79% vs 90%; P < 0.01) and procedural success (77% vs 89%; P < 0.01) rates compared with non-ambiguous CTO lesions. The incidence of major adverse cardiovascular events (MACE) was higher in cases with proximal cap ambiguity (2.5% vs 1.7%; P < 0.01). The retrograde approach was more commonly used among cases with ambiguous proximal cap (51% vs 21%; P < 0.01) and was more likely to be the final successful crossing strategy (29% vs 13%; P < 0.01). PCIs of CTOs with ambiguous proximal cap required longer procedure time (140 [95-195] vs 105 [70-150] min; P < 0.01) and more contrast volume (225 [160-305] vs 200 [150-280] mL; P < 0.01).

Conclusion: Proximal cap ambiguity in CTO lesions is associated with higher utilization of the retrograde approach, lower technical and procedural success rates, and higher incidence of in-hospital MACE.

Categories: CORONARY: Complex and Higher Risk Procedures for Indicated Patients (CHIP)





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