Identification of completed coronary stent healing by optical coherence tomography - validation study with histopathology in porcine model of coronary restenosis.

BACKGROUND

The potential of optical coherence tomography (OCT) is limited by incomplete validation with histopathology. The study aimed to assess whether OCT can identify a completely healed coronary stent.

MATERIAL AND

METHODS

The study included 40 swine and total of 106 stents (82 DES, 24 BMS). Follow-up OCT and histopathology examination was done after 28 days (n = 53) and 90-days (n = 53). 273 frames were matched between histopathology and OCT. Histopathologic criteria for completed healing: high endothelialization score (2-3), low inflammation score (0-1), low fibrin score (0-1), high neointimal smooth muscle score (2-3) and lack of binary restenosis.

RESULTS

Predictors of a well healed stent were presence of homogenous neointima (OR: 2.53) and the total number of struts per section (OR: 1.11). The presence of microvessels (OR: 0.28) and increasing neointimal area (OR: 0.65) predicted incomplete healing. Cutoff values were identified: inflammation score was the highest in segments with neointima thickness over 0.35 mm. Persistent fibrin deposits were found at 28-day follow-up in DES with less than 13 embedded struts per section and neointima area less than 2.234 mm². The number of embedded struts per section showed a positive correlation with the healing score, while both protruding covered and protruding uncovered struts showed a negative correlation.

CONCLUSIONS

OCT demonstrated moderate ability to predict completed stent healing.