Periprocedural outcome of the single-branched ISG was acceptable, and long-term safety and efficacy were demonstrated. However, the procedural complications of the multibranched ISG leave room for improvement.

We assessed long-term outcomes after left main coronary artery (LMCA) stenting based on lesion types and stenting strategies. In the Assessing Optimal percutaneous coronary Intervention for Left Main Coronary Artery stenting registry, we evaluated 1,607 consecutive patients undergoing stent implantation for unprotected LMCA lesions (bifurcation lesions: n = 1318 and nonbifurcation lesions: n = 289). Among the bifurcation lesions, 1,281 lesions were treated with stenting across the bifurcation (bifurcation 1-stent strategy: n = 999 or bifurcation 2-stent strategy: n = 282). Among the nonbifurcation lesions, 219 lesions were treated with nonbifurcation stenting. The median follow-up duration was 4.6 (95% CI 4.5 to 4.8) years. The 5-year risk of bifurcation lesions relative to nonbifurcation lesions was neutral for target lesion revascularization (TLR) (adjusted hazard ratio [HR] 0.82, 95% CI 0.55 to 1.23, p = 0.34) and all-cause death (adjusted HR 1.22, 95% CI 0.87 to 1.71, p = 0.26). The risk of the bifurcation 1-stent strategy relative to nonbifurcation stenting in nonbifurcation lesions was also neutral for TLR (adjusted HR 1.19, 95% CI 0.74 to 1.90, p = 0.47) and all-cause death (adjusted HR 0.81, 95% CI 0.56 to 1.18, p = 0.27). However, the bifurcation 2-stent strategy was associated with worse clinical outcomes than the bifurcation 1-stent strategy in TLR (adjusted HR 1.76, 95% CI 1.23 to 2.52, p = 0.002) and definite or probable stent thrombosis (crude HR 3.50, 95% CI 1.32 to 9.33, p = 0.01), despite neutral risk for all-cause death (adjusted HR 1.00, 95% CI 0.74 to 1.36, p = 0.99). There was no definite or probable very late stent thrombosis up to 5 years. In conclusion, long-term outcomes after stent implantation for unprotected LMCA lesions were not dependent on the bifurcation lesion types but related to the bifurcation stenting strategies with worse outcomes for the bifurcation 2-stent strategy.

We aimed to investigate the effectiveness of a scoring balloon catheter in expanding a circumferentially calcified lesion compared to a conventional balloon catheter using an in vitro experiment setting and elucidate the underlying mechanisms of this ability using a finite element analysis. True efficacy of the scoring device and the underlying mechanisms for heavily calcified coronary lesions are unclear. We employed a Scoreflex scoring balloon catheter (OrbusNeich, Hong Kong, China). The ability of Scoreflex to dilate a calcified lesion was compared with a conventional balloon catheter using 3 different sized calcium tubes. The thickness of the calcium tubes were 2.0, 2.25, and 2.5 mm. The primary endpoints were the successful induction of cracks in the calcium tubes and the inflation pressures required for inducing cracks. The inflation pressure required for cracking the calcium tubes were consistently lower with Scoreflex (p < 0.05, Student t test). The finite element analysis revealed that the first principal stress applied to the calcified plaque was higher by at least threefold when applying the balloon catheter with scoring elements. A scoring balloon catheter can expand a calcified lesion with lower pressure than that of a conventional balloon. The finite element analysis revealed that the concentration of the stress observed in the outside of the calcified plaque just opposite to the scoring element is the underlying mechanism of the increased ability of Scoreflex to dilate the calcified lesion.

Two novel equations which predict the true FFR of LMCA stenosis were demonstrated to be correct. The study also revealed that the functional impact of downstream stenoses on the LMCA stenosis became stronger when the downstream stenoses became more severe.

No abstract