Neointimal Healing Score After Contemporary Extraplaque Compared to Intraplaque Recanalization of Chronic Total Occlusion: A 6-Month Follow-Up Optical Coherence Tomography Observational Study.

BACKGROUND: The expanding utilization of extraplaque (EP) strategies has led to increasing success rates in coronary chronic total occlusion (CTO) recanalization. The contemporary EP techniques have shown mid-term outcomes comparable to intraplaque (IP) recanalization approaches. Differential neointimal healing after CTO recanalization by various approaches remains to be identified. AIM: This study aimed to assess the vascular healing response across different CTO recanalization techniques using optical coherence tomography (OCT)-derived Neointimal Healing Score (NIHS). METHODS: This was a prospective, observational, analytic, single-center study recruiting 50 consecutive patients who underwent successful recanalization of 51 coronary CTOs. The recanalization technique (EP vs. IP) was according to the operator's discretion based on the CTO anatomical characteristics. The study aimed to compare the impact of the EP versus IP recanalization technique on the vascular healing assessed by OCT-derived NIHS (evaluating the presence of uncovered and/or malapposed stent struts and intraluminal filling defects), 6 months after the index procedure. RESULTS: The mean age was 58 ± 8 years, and 35 (70%) were males. EP and IP techniques were used in 15 and 36 of the recanalized CTOs, respectively. At 6 months, clinical and angiographic follow-ups were completed for all patients, while interpretable OCT imaging was available for 39 patients (77%). The mean NIHS for all patients was 14.3 ± 9.7. The NIHS was comparable between EP and IP techniques (18 ± 7.4 vs. 14.1 ± 8.4; p = 0.51). Target vessel failure (TVF) occurred in 23.5% of all patients with a numerically nonsignificant higher rate in the EP compared to the IP technique (27% vs. 22%; p = 0.73). CONCLUSION: CTO recanalization using EP techniques is associated with a nonsignificant numerical increase in NIHS without leading to a significant difference in TVF compared to IP techniques at mid-term follow-up.