Microcatheter collateral channel tracking failure in retrograde percutaneous coronary intervention for chronic total occlusion: incidence, predictors, and management.

AIMS: This study sought to demonstrate the incidence, predictors, and management of microcatheter collateral channel (CC) tracking failure in retrograde percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) lesions. METHODS AND RESULTS: Prospectively collected data from 371 consecutive retrograde CTO-PCI procedures between March 2015 and January 2018 were retrospectively analysed. The incidence of initial microcatheter CC tracking failure was 22.5% in 280 procedures with wire CC tracking success. For septal collaterals, CC grade 0-1 collaterals (odds ratio [OR]: 8.3; p<0.001), channel entry angle <90° (OR: 13.0; p=0.001), channel exit angle <90° (OR: 44.3; p=0.004), and Finecross MG as initial microcatheter (OR: 2.7; p=0.032) were independently related to initial microcatheter CC tracking failure. Meanwhile, the only predictor for epicardial collaterals was CC 1 collaterals (OR: 26.9; p<0.001). Frequently applied solutions included microcatheter switching (61.9%), and microcatheter switching combined with GUIDEZILLA (14.3%) or anchoring balloon technique (6.3%). CONCLUSIONS: Initial microcatheter CC tracking failure was found in nearly one quarter of procedures after wire CC tracking success. Independent angiographic predictors of initial microcatheter CC tracking failure included CC 0-1 collaterals, channel entry angle <90°, and channel exit angle <90° for septal collaterals, and CC 1 collaterals for epicardial collaterals.

[Virtual histology intravascular ultrasound assessment of coronary atherosclerotic plaques in diabetic patients].

OBJECTIVE: To evaluate the components and characteristics of coronary atherosclerotic plaques in type 2 diabetic patients using virtual histology intravascular ultrasound (VH-IVUS). METHODS: In vivo atherosclerotic plaques (over 50% angiographic diameter stenosis) of the three main coronary arteries were analyzed by gray-scaled IVUS with planar and volumetric VH-IVUS in consecutive patients examined between September 2008 and March 2009. Patients were divided into two groups: diabetic mellitus (DM) group with 22 patients (39 lesions) and non-DM group with 46 patients (69 lesions). RESULTS: At the minimal lumen area (MLA) site, the percentage of NC (necrotic core) area (19.4% +/- 1.2% vs. 15.1% +/- 1.1%, P = 0.015) and dense calcium (DC) area (15.2% +/- 1.6% vs. 10.7% +/- 1.1%, P = 0.016) were significantly larger while fibrotic tissue (FT) area (56.7% +/- 2.3% vs. 64.8% +/- 1.8%, P = 0.007) was smaller in DM group than in non-DM group. Likewise, volumetric VH-IVUS analysis showed that the percentage of NC volume (21.3% +/- 1.3% vs. 16.5% +/- 1.1%, P = 0.008) and DC volume (16.6% +/- 1.4% vs. 11.3% +/- 1.1%, P = 0.003) were significantly larger while FT volume (55.1% +/- 2.1% vs. 63.9% +/- 1.8%, P = 0.003) was significantly smaller in DM group than in non-DM group. Moreover, significantly higher incidence of VH-TCFA (thin-cap fibro atheromas) was evidenced in the DM group than in the non-DM group (69.2% vs. 42.0%, P = 0.009). However, the remodeling index and the positive remodeling frequency were similar between the 2 groups. CONCLUSION: Incidence of necrotic core, dense calcium plaque and vulnerable plaques in stenotic lesions was higher in DM patients than in non-DM patients.