Masashi Kimura

Although retrograde approach for coronary chronic total occlusion (CTO) has been introduced, the procedure is still time and resource consuming. A simplified antegrade approach mightbe another resort. The aim of this study was to evaluate a new device designed to facilitate guidewire re-entry into the true lumen of a CTO from the adjacent subintimal space. Patients with CTO were entered into a prospective registry regardless of lesion characteristics. A new metal-tip catheter was used initially in primary use cases. If it created subintimal tracking, a new re-entry tool (a flat balloon with 2 exit ports offset by 180 degrees) was used as a platform to attempt guidewire penetration into the distal true lumen. In rescue use cases after unsuccessful conventional wiring, the re-entry procedure was subsequently attempted. In 11 CTO lesions attempted, device success was achieved in 8 cases (72.7%). Re-entry procedure success rate was higher in primary use cases (80%) compared to rescue use cases (33.3%). Retrograde approach was conducted immediately after unsuccessful antegrade procedure using this device in the other 3 cases and successful recanalization was achieved in all cases. All lesions were stented, resulting in TIMI 3 flow without major complications. A new coronary re-entry device may provide another strategic option in the antegrade approach to recanalize CTOs.

Percutaneous coronary intervention (PCI) for chronic total occlusions (CTO) remains a challenge. Multislice computed tomographic coronary angiography (CTCA) allows noninvasive evaluation of the coronary artery by visualizing vessel trajectory and morphological features at the occluded site. The aim of this study was to assess the value of CTCA to predict the success of guidewire crossing in PCI to treat CTOs. We performed CTCA in patients with CTOs (of > 3 months' duration); 110 lesions were scanned. Wiring success was defined as complete crossing of the guidewire past the occluded site. Correlation of the following morphological parameters with wiring success was analyzed: target vessel bending (defined as > 45 degrees), shrinkage, severe calcification, presence of side branches, stump morphology, in-stent occlusion and occlusion length. Wiring success was obtained in 93 lesions (85%). In the unsuccessful group, bending, shrinkage and severe calcification were significantly higher compared to the successful group (76% vs. 18%, p < 0.0001; 29% vs. 4%, p = 0.0005; 41% vs. 18%, p = 0.0356, respectively). The wiring success rate was significantly lower in cases with bending, shrinkage and severe calcification (57% vs. 95%, p < 0.0001; 44% vs. 88%, p = 0.0005; 71% vs. 88%, p = 0.0356, respectively). Stump morphology, in-stent occlusion or occlusion length did not significantly affect the outcome. Multivariate analysis showed that bending, shrinkage and severe calcification remained significant independent predictors of wiring failure. Bending, shrinkage and severe calcification are significant predictors for wiring success. CTCA provides a practical determinant of the outcomes in PCI to treat CTOs.

The impact of plaque debulking with directional coronary atherectomy (DCA) prior to single sirolimus-eluting stent (SES) implantation in an unprotected left main coronary artery (LMCA) involving bifurcation stenosis has not been fully evaluated. One hundred and one patients with unprotected LMCA bifurcation lesions treated with single SES implantation (from the LMCA to the left descending coronary artery [LAD] across the left circumflex artery [LCx] ostium) were divided into 2 groups: DCA group (n = 41, plaque debulking with DCA prior to SES implantation) and non-DCA group (n = 60, single SES implantation alone). Clinical outcomes as well as angiographic data at baseline, post procedure and follow up were compared between the two groups. At 1-year follow up, freedom from major adverse cardiac events was 97.4 +/- 2.6% in the DCA group, and 88.6 +/- 4.4% in the non-DCA group (p = 0.129). Baseline quantitative coronary angiographic analyses revealed that the percent diameter stenosis (%DS) of the LCx was higher in the DCA group than in the non-DCA group (36.8 +/- 21.5% vs. 26.9 +/- 19.2%; p = 0.029). Moreover, the %DS of the LCx after PCI and at 9-month follow up was lower in the DCA group (19.2 +/- 13.1% vs. 28.3 +/- 22.7%; p = 0.034; 20.8 +/- 12.3% vs. 31.9 +/- 21.4%; p = 0.007, respectively). Furthermore, restenosis at the LCx ostium was not observed in the DCA group, but was seen in 5 cases in the non-DCA group (0% vs. 10.2%; p = 0.048). Plaque debulking with DCA prior to single SES implantation effectively reduced restenosis of the LCx ostium in this challenging lesion subset.