Effect of coronary bifurcation angle on clinical outcomes in Chinese patients treated with crush stenting: A subgroupanalysis 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% CI 2.975-5.431, 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.