Mechanisms and clinical significance of quality of final kissing balloon inflation in patients with true bifurcation lesions treated by crush stenting technique

Background The mechanisms responsible for the occurrence of a kissing unsatisfied （KUS） result after classical crush stenting remain unclear. The present study aimed at analyzing the mechanisms and clinical significance of KUS. Methods Two hundred and thirteen patients with true bifurcation lesions treated with classical crush stenting and final kissing balloon inflation （FKBI） were assigned to upper, middle, and lower groups according to the position of the side branch re-wiring assessed by visual estimation, quantitative coronary analysis （QCA） and intravascular ultrasound （IVUS）. Angiographic follow-up was indexed at 12 months. Results The upper group was characterized by a larger bifurcation angle of 55.53°±25.25° （P=0,030） and a longer procedural time （42.43±23.92） minutes （P=0.015）. The overall rate of KUS by visual estimation was 10.48%, with 5.4% in the upper group, 3.9% in middle group, and 36.1% in lower group （P 〈0.001）. For the diagnosis of KUS, visual inspection demonstrated a good correlation with both QCA and IVUS. Smaller stent diameter was the main reason for KUS in the upper group, while extra-stent side wire location, or re-wire in a low position was the main mechanism attributed to KUS in the lower group. The Lower group had more restenosis, with most restenotic lesions at a lower position of the side branch ostium. KUS （HR 1.652, 95% Cl 1.332-2.088, P 〈0.001） and re-wiring position （HR 2.341, 95% Cl 1.780-4.329, P 〈0.001） were two independent predictors of side branch restenosis. Re-wiring position （OR 0.458, 95%C/0.336-0.874, P=0.001） and side stent expansion （OR 3.122, 95%C/2.883-5.061, P=0.014） were factors predicting the findings of KUS. Conclusions Side wire outside side stents resulted in more KUS and restenosis. Different restenotic lesion types reflected individual mechanisms contributing to the development of plaque proliferation.

Effect of coronary bifurcation angle on clinical outcomes in Chinese patients treated with crush stenting： a subgroup analysis from DKCRUSH-1 bifurcation study

Background Bifurcation angles may have an impact on the clinical outcomes of crush stenting. We sought to compare high （≥60°） with low （〈60°） bifurcation angle in patients who underwent either classical or double kissing （DK） crush stenting for bifurcation lesions from the DKCRUSH-1 data base. Methods There were 212 patients with 220 lesions, some with low-angle （n=138） and some with high-angle （n=74）. Angiography was indexed at 8-month after procedure. Primary endpoint was the occurrence of major adverse cardiac events （MACEs）, defined as cardiac death, myocardial infarction and target lesion revascularization （TLR）. Secondary endpoint included late lumen loss, the rate of restenosis, and final kissing balloon inflation （FKBI）. Results At 8 months, clinical follow-up was 100%; angiographic follow-up was 75% in the low-angle group and 83.3% in the high-angle group. There were no significant differences in the FKBI between the high-angle group （91.43%） and the low-angle group （82.39%）. In the high angle group, there was a significant difference in contrast volume used （P=0.005） but no significant difference in acute gain, minimum lumen diameter （MLD）, late loss and diameter stenosis in the pre-bifurcation segment, post-bifurcation segment or side branch. When lesions were assigned into with- （n=-133） and without-FKBI （n=42）, significant side-branch late loss was seen in the group without-FKBI （（0.65±0.49） mm vs （0.47±0.62） mm, P=0.02）, with a resultant greater restenosis rate （37.68% vs 18.32%, P=0.001）. No difference was detected in the MACE free survival rate between the high and low angle groups （82.39% vs 82.36%, P=0.84）. The rate of stent thrombosis tended to be higher in the lower-angle group although there was no significant difference （P=0.38）. The TLR free survival rate was 87.2% in the with-FKBI group vs 73.5% in the without-FKBI group （P=0.001）. Cox regression analysis showed that the independent predictors for target vessel revascularization were the side branch stent MLD post stenting （hazard ratios （HR） 1.028, 95% CI 2.357-16.233, P=0.002）, lack of FKBI （HR 4.910, 95% CI 4.706-8.459, P=0.001） and unsatisfactory kissing （HR 3.120, 95% CI2.975-5.431, P=0.001）. Conclusions Bifurcation angles do not influence the clinical outcome of crush stenting. Successful final kissing balloon inflation, regardless of bifurcation angles, can predict TLR.

Crush stenting in treating coronary bifurcate lesions： paclitaxel eluting stents versus sirolimus eluting stents

Background Because no data regarding the comparison of crush stenting with paclitaxel （PES） or sirolimus eluting stents （SES） for coronary bifurcate lesions have been reported, we compared the clinical outcomes of these two types of stents. Methods Two hundred and thirty patients with 242 bifurcate lesions were enrolled in a prospective, nonrandomized trial Primary endpoints included myocardial infarction, cardiac death and target vessel revascularization at 8 months. Results All patients were followed up clinically and 82% angiographically at 8 months. Final kissing balloon inflation was performed in 72% in the PES and 75% in the SES groups （P〉0.05）. Compared to the SES group, PES group had a higher late loss and incidence of restenosis （P=0.04） in the prebifurcation vessel segment. The postbifurcation vessel segment in the PES group had a greater late loss （（0.7±0.6） mm vs （0.3±0.4） mm, P〈0.001） and higher restenosis in the side branch （25.5% vs 15.6%, P=0.04） when compared to the SES group. There was significant difference of insegment restenosis in the entire main vessel between PES and SES groups （P=0.004）. Target lesion revascularization was more frequently seen in the PES group as compared to the SES group （P=0.01）. There was significant difference in the accumulative MACE between these two groups （P=-0.01）. The survival rate free from target lesion revascularization was significantly higher in the SES group when compared to the PES group （P〈0.001）. Conclusion SES is superior to PES in reducing restenosis and target lesion revascularization by 8-month follow-up after crush stenting for bifurcate lesions.