SS–13 Association of Final Kissing Balloon Inflation with Major Adverse Cardiac Events in Provisional Crossover Stenting of Distal Left Main Coronary Bifurcation Lesions: A SingleCentre Retrospective Analysis

Abstract

Introduction and Aim: In a provisional single-stent strategy for distal left main (LM) coronary bifurcation lesions, final kissing balloon (FKB) inflation may be performed when stenosis develops at the ostium of the unstented side branch after crossover stenting of the main vessel; whether FKB should be routine or reserved for this situation remains debated. In this study, we compared the characteristics and major adverse cardiac event (MACE) rates of patients who did and did not undergo FKB in a real-world provisional LM bifurcation crossover cohort.

Methods: A total of 150 consecutive patients treated with provisional single-stent LM bifurcation crossover at a single centre were reviewed retrospectively; cases in which a stent was implanted in the side branch were excluded. According to the stent target, 126 cases were classified as LM–left anterior descending artery (LM-LAD) and 24 as LM–circumflex (LM-Cx) crossover; the proximal optimisation technique (POT) was performed in 98.0% of cases. FKB was performed in cases that developed more than 70% stenosis at the side-branch ostium after crossover (n=17; 11.3%); the remaining 133 cases formed the control group. The primary outcome was MACE (a composite of allcause death, myocardial infarction and target lesion revascularisation). Group comparisons were made with Fisher's exact test for categorical variables and the Mann-Whitney U test for continuous variables; associations with rare events were modelled with Firth penalised logistic regression. No correction for multiple comparisons was applied, and p values (p<0.05) are descriptive.

Results: In the overall cohort, the median age was 62.5 years, 73.3% of patients were male and 52.0% presented with acute coronary syndrome (ACS); intravascular ultrasound (IVUS) use was limited (7.3%). The FKB and no-FKB groups did not differ significantly in baseline characteristics; the only statistically significant difference was in ejection fraction (median 60% vs 51.2%; p=0.030), although both medians were within normal limits (>50%). Baseline side-branch stenosis was below 50% in both groups and the groups were comparable. MACE occurred in 14.7% of patients (22/150). For the primary outcome, the MACE rate did not differ between the two groups (17.6% vs 14.3%; odds ratio (OR) 1.29; 95% confidence interval (CI) 0.34–4.90; risk difference +3.4%; 95% CI −15.7% to +22.4%; p=0.72). No significant differences were found for in-hospital mortality (0% vs 7.5%), all-cause mortality (11.8% vs 11.3%), myocardial infarction (0% vs 3.0%) or target lesion revascularisation (6.2% vs 1.5%; p=0.60, 1.00, 1.00 and 0.29, respectively). In the Firth models, low haemoglobin (OR 1.49 per 1 g/dL decrease; 95% CI 1.18–1.92) and presentation with ACS (OR 3.14; 1.16–9.49) were independently associated with MACE, and low estimated glomerular filtration rate (eGFR; OR 1.32 per 10 mL/ min/1.73 m² decrease; 1.08–1.62) and ACS (OR 4.61; 1.43–19.29) with all-cause mortality.

Conclusion: In a real-world provisional LM bifurcation crossover cohort in which the side branch was largely preserved before the procedure, final kissing balloon inflation was performed only in cases that developed stenosis at the side-branch ostium after crossover, and no significant difference was found between the groups in MACE or its components. However, the small size of the FKB group (n=17) and the wide confidence interval render this comparison underpowered to exclude a clinically meaningful difference; moreover, because the FKB group is by definition a selected subgroup that developed side-branch ostial stenosis, the groups also differ with respect to the development of this potentially prognostically unfavourable stenosis. Therefore, although there is no evidence that FKB is harmful, a benefit has not been demonstrated either; the findings are hypothesis-generating and should be confirmed in adequately powered prospective studies. The decision to perform FKB remains an individualised, case-by-case decision based on the post-stenting angiographic result.