Clinical impact of a new optical coherence tomography-derived volumetric method for evaluating stent expansion

The aim of this study was to investigate the impact of a new optical coherence tomography (OCT)-derived volumetric method for stent expansion (new-OCT method) to predict the target lesion revascularization (TLR) and compare the expansion findings between this new method and the conventional method because, in the real world, there are few clinical data on the new-OCT-method for stent expansion. One hundred forty lesions in 135 patients who underwent OCT-guided percutaneous coronary intervention were enrolled. We compared the new-OCT-method and conventional method to predict the TLR at 1 year. A total of 7 lesions (5.0% of treated lesions) in 6 patients experienced TLR during 1 year of follow up. The minimum expansion index (MEI) using the new-OCT method was significantly lower in the TLR group than non-TLR (60.0% vs. 77.0%; p < 0.001) while the conventional method for assessing stent expansion did not show a statistically significant difference between the two groups (71.3% and 79.7%; p = 0.118). The univariate analysis showed that the stent length, minimum stent area, minimum lumen area, MEI, and renal insufficiency/failure, were significant predictors of a 1-year TLR. The multivariate model identified the stent length, MEI, and renal insufficiency/failure as the independent predictors of TLR and the value of the MEI was the only predictor in the OCT findings. The new OCT-derived volumetric method for stent expansion is superior to the conventional method for predicting the TLR at 1 year. The MEI may be the most practical and efficient way to estimate stent under-expansion.