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In drug-eluting stent (DES) era, optimal stent expansion (OSE) has been associated with favorable clinical outcomes. In contrast, uncovered stent strut may increase the risk of late DES failure. The relationship of these variables, however, has not been clarified.
We recruited 72 DES-treated lesions in 69 consecutive patients who underwent optical coherence tomography (OCT) examination both post-procedure and at 9-18 months (median 12 months) follow-up. OCT parameters were assessed in each 1mm intervals within stented segments. OSE was defined as post-procedural minimal stent area (MSA) > 90% of the mean reference lumen area on OCT images.
OSE was identified in 29 lesions (40.3%). In the OSE group, MSA was significantly larger at post-procedure (7.12 mm2 vs. 5.92mm2, p=0.020) and the percentage of uncovered stent strut was significantly lower (2.52% vs. 3.85%, p=0.042, table 1) compared to the non-OSE group. Stent expansion was negatively correlated with uncovered stent struts (r=-0.269, p=0.022, figure 1).
|OSE (29 lesions)||NonOSE (43 lesions)||P-value|
|FU Stent CSA, mm2||8.08±2.40||7.46±2.06||0.242|
|FU Lumen CSA, mm2||7.42±2.44||6.98±2.02||0.412|
|FU NIH CSA, mm2||0.69±0.51||0.50±0.36||0.065|
|FU Apposed & Covered, %||97.21||96.02||<0.0001|
|FU Apposed & Uncovered, %||2.32||3.58||<0.0001|
|FU Malapposed & Covered, %||0.22||0.25||0.673|
|FU Malapposed & Uncovered, %||0.10||0.11||0.771|
|FU Orifice branch site & Covered, %||0.12||0.00||<0.0001|
|FU Orifice branch site & Uncovered, %||0.03||0.04||1.000|
Achievement of OCT-guided OSE may improve the coverage of stent struts.
IMAGING: Imaging: Intravascular