Background: Little is known of the relationship between optical coherence tomography (OCT) findings and recurrent restenosis after paclitaxel-coated balloon (PCB) angioplasty for drug-eluting stent in-stent restenosis (DES-ISR). To identify the predictors of recurrent restenosis after PCB angioplasty, we investigated quantitative and qualitative OCT findings during PCB angioplasty for DES-ISR. Methods and Results: In all, 222 DES-ISR lesions treated by PCB angioplasty with OCT assessment and followed-up angiographically at 6 months were divided into restenotic and non-restenotic lesions on the basis of the presence or absence of restenosis at follow-up. There was a significantly higher proportion of the heterogeneous tissue pattern in restenotic than non-restenotic lesions (26.5% vs. 11.0%, respectively; P=0.02). The OCT-derived post-procedural minimal lumen and stent areas were significantly smaller in restenotic lesions, but the intima area was similar in both groups. Post-procedural stent underexpansion, defined as a stent diameter : size of the previous stent ratio <1.0, was more frequently observed in restenotic than non-restenotic lesions (33.3% vs. 17.4%, respectively; P=0.02). Multivariate analysis identified a heterogeneous tissue pattern (odds ratio [OR] 2.92; 95% confidence interval [CI] 1.32-6.47; P=0.006) and post-procedural stent underexpansion (OR 2.36; 95% CI 1.15-4.85; P=0.04) as independent predictors of recurrent restenosis.
Conclusions: The heterogeneous tissue pattern and insufficient post-procedural minimal lumen area, caused primarily by stent underexpansion, may be associated with restenosis after PCB angioplasty for DES-ISR.
Keywords: In-stent restenosis; Optical coherence tomography; Paclitaxel-coated balloon.