Predictors and 3‐year outcomes of compromised left circumflex coronary artery after left main crossover stenting

Abstract

Background: There are few predictors of decreased fractional flow reserve (FFR) in the left circumflex coronary artery (LCx) after left main (LM) crossover stenting.Objectives: We aimed to determine the predictors for low FFR at LCx and possible treatment strategies for compromised LCx, together with their long-term outcomes. Methods: Altogether, 563 patients who met the inclusion criteria were admitted to our hospital from February 2015 to November 2020 with significant distal LM bifurcation lesions. They underwent single-stent crossover percutaneous coronary intervention (PCI) under intravascular ultrasound (IVUS) guidance with further LCx intervention based on the measured FFR. Results: The patients showed significant angiographic LCx ostial affection post-LM stenting, but only 116 (20.6%) patients had FFR < 0.8. The three-year composite major adverse cardiac events (MACE) rates were comparable between the high and low FFR groups (16.8% vs. 15.5; p = 0.744). In a multivariate analysis, low FFR at the LCx was associated with post-stenting minimal luminal area (MLA) of LCx (odds ratio [OR]: 0.032, p < .001), post-stenting LCx plaque burden (OR: 1.166, p < .001), poststenting LM MLA (OR: 0.821, p = .038), and prestenting LCx MLA (OR: 0.371, p = .044). In the low FFR group, those with compromised LCx managed with drugeluting balloon had the lowest three-year MACE rate (8.1%), as compared to either those undergoing kissing balloon inflation (KBI) (17.5%) or stenting (20.5%) (p = 0.299). Conclusion: Unnecessary LCx interventions can be avoided with FFR-guided LCx intervention. Poststenting MLA and plaque burden of the LCx, and main vessel stent length are poststenting predictors of low FFR.

Management of failed stenting of the unprotected left main coronary artery

“…The ostium of the LCX is the area of the left main which is particularly prone to failure of PCI 30,31 . This is in part due to the increased restenosis rate of ostial lesions per se but also the common presence of calcification restricting stent expansion 32 .…”

“…26 Indeed, LMCA lesion location per se is an independent correlate of significant coronary calcification. 27 The ISAR-LEFT-MAIN trial demonstrated the prognostic role of anatomical complexity showing a significantly lower TLR rate at 3 years in patients with SYNTAX scores ≤22 as compared to patients with intermediate (23)(24)(25)(26)(27)(28)(29)(30)(31)(32) and high (≥33) scores (9.2% vs. 14.9% vs. 13.0%, respectively, p = 0.008). 24 Moreover, the involvement of "true" ULMCA bifurcation (Medina 1,1,1) was an independent predictor of TLR (HR 2.12 95% CI: 1.19-3.77, p = 0.011).…”

“…28,29 The ostium of the LCX is the area of the left main which is particularly prone to failure of PCI. 30,31 This is in part due to the increased restenosis rate of ostial lesions per se but also the common presence of calcification restricting stent expansion. 32 Geographic stent miss, inadvertent longitudinal and radial stent deformation 33 and chronic stent fracture induced by cardiac motion inducing cyclic angulation after stent implantation may also be important.…”