Intravascular ultrasound analysis of intraplaque versus subintimal tracking in percutaneous intervention for coronary chronic total occlusions: One year outcomes.

OBJECTIVES: We sought to determine the 1-year outcomes of patients receiving successful chronic total occlusion (CTO) percutaneous coronary intervention (PCI) procedures comparing subintimal versus intraplaque wire tracking patterns.

BACKGROUND: CTO PCI utilizes both intraluminal and subintimal wire tracking to achieve successful percutaneous revascularization. Intravascular ultrasound (IVUS) can be used to precisely determine the path of wire tracking.

METHODS: From 2014 to 2016, data from patients undergoing CTO PCI were collected in a single-center database. The primary composite endpoint was target vessel failure (TVF) defined as cardiovascular death, target vessel myocardial infarction (MI), or target vessel revascularization (TVR).

RESULTS: In total 157 patients with successful CTO PCI and concomitant IVUS imaging completed 1-year follow-up. Subintimal tracking was detected in 53.5% of cases and those patients had a higher incidence of prior PCI, prior coronary artery bypass grafting, and higher J-CTO score. At 1-year, the unadjusted rate of TVF in the subintimal tracking group was higher than the intraplaque group (17.9 vs. 6.9%, HR 2.74, 95% CI 1.00-7.54, P = 0.04), driven by numerically higher rates of TVR and peri-procedural MI. After multivariable adjustment, no significant differences in the rates of the TVF between subintimal vs. intraplaque groups were present at 1-year (TVF: HR 1.51, 95% CI 0.38-6.00, P = 0.55). Landmark analysis excluding in-hospital events showed no significant differences in TVF to 1-year.

CONCLUSIONS: IVUS-detected subintimal tracking was observed in over half of successful CTO PCI cases and correlated with baseline and angiographic factors that contributed to the overall rate of TVF at 1-year.