Benefit of Final Kissing Balloon Inflation Mandatory After Simple Crossover Stenting for Left Main Bifurcation Narrowing

Provisional Strategy for Left Main Stem Bifurcation Disease: A State-of-the-Art Review of Technique and Outcomes

Left main coronary artery (LMA) disease jeopardizes a large area of myocardium and increases the risk of major adverse cardiovascular events. LMCA disease is found in 5% to 7% of all diagnostic coronary angiographies, and more than 80% of the patients enrolled in recent large randomized controlled left main trials had distal left main bifurcation or trifurcation disease. Emerging clinical evidence from prospective all-comer registries and randomized trials has provided a solid basis for percutaneous coronary intervention as a treatment option in selected patients with unprotected LMCA disease; however, to date, no uniform recommendations as to optimal stenting strategy for LMCA bifurcation lesions exist. This review provides an overview of provisional stenting technique and escalation to 2-stent strategies in LMCA bifurcation lesions. Data from randomized controlled trials and registries are reviewed. Technical characteristics of optimal provisional LMCA stenting technique and angiographic and intravascular determinants of escalation are also summarized.

Clinical Characteristics and Outcomes following Percutaneous Coronary Intervention in Unprotected Left Main Disease: A Single-Center Study

Background: Hemodynamically significant unprotected left main (LM) coronary artery disease is a high-risk clinical condition because of the large area of myocardium at risk, and it requires prompt revascularization. Percutaneous coronary intervention (PCI) is an appropriate alternative to coronary artery bypass grafting (CABG) for revascularization of unprotected LM disease in patients with low-to-intermediate anatomic complexity or when the patient refuses CABG after adequate counseling by the heart team. Methods: We retrospectively evaluated 201 patients receiving left main (LM) provisional one-stent or two-stent procedures, and we assessed the clinical characteristics and outcomes of patients undergoing unprotected LM PCI. Results: The mean age was 66.5 ± 9.9 years, and 72% were male. The majority of the subjects presented several cardiovascular risk factors, among which arterial hypertension (179 patients, 89.5%) and dyslipidemia (173 patients, 86.5%) were the most frequent. Out of all patients, 162 (81.8%) underwent revascularization by using the one-stent technique, while the two-stent technique was used in 36 patients (18.2%). The median value of fractional flow reserve (FFR) of the side branch was 0.9 [0.85–0.95], and 135 patients (67.1%) showed a value of FFR > 0.8. One hundred nine patients (54.2%) had a stent enhancement side branch length (SESBL) > 2, with median values of 2.5 mm2 [2.1–3]. Regarding angiographic parameters, the LM area as assessed by intravascular ultrasound (IVUS) or optical coherence tomography (OCT) and the grade of stenosis as assessed by quantitative coronary angiography (QCA) were similar between groups. However, patients who required revascularization by using the two-stent technique presented more frequently with intermediate rather than low SYNTAX scores (69.4% vs. 28.4%, p < 0.0001). Also, the same group required kissing balloon inflation (KBI) more frequently (69.4% vs. 30%, p < 0.001). There were no differences regarding the success of revascularization between the use of the one-stent or two-stent technique. FFR was able to predict a SESBL > 2 mm. The cut-off value for FFR to afford the highest degree of sensitivity (74.5%) and specificity (47%) for a SESBL > 2 was >0.86, indicating a moderate accuracy (AUC = 0.61, 95% CI 0.525–0.690, p = 0.036). Conclusions: Unprotected left main PCI is a safe and effective revascularization option amongst a complex and morbid population. There were no differences regarding the success of revascularization between the use of the one-stent or two-stent technique, and there was no significant impact of KBI on side branch FFR measurements but lower side branch FFR values were correlated with angiographic side branch compromise.

Long-term prognostic value of Murray law-based quantitative flow ratio in jailed left circumflex coronary artery after left main crossover stenting

We aimed to evaluate the impact of new Murray law-based QFR of jailed left circumflex coronary artery (LCx) on long-term clinical outcomes after left main coronary artery (LM) simple crossover stenting. 164 patients who underwent LM-to-left anterior descending coronary artery simple crossover stenting and had appropriate angiographic view of LCx for QFR computation were enrolled. The primary clinical outcome was the 5-year target lesion failure (TLF), defined as a composite of cardiac death, a target vessel myocardial infarction or target lesion repeat revascularization. The mean QFR of the LCx after LM stent implantation was 0.88 ± 0.09, and 29 patients (17.7%) had a low QFR (< 0.80), which was significantly associated with a higher 5-year rate of TLF when compared with the high QFR group (27.6% vs. 6.7%; HR: 4.235; 95% CI 1.21-14.95; p = 0.0015). The 5-year LCx ostium-related TLR rate in the low QFR group was also higher (17.2% vs. 3.0% in the high QFR group; HR: 6.07, 95% CI 1.63-22.59, p = 0.002). In a multivariate Cox regression analysis, a low QFR in the LCx after LM stenting was an independent predictor of the 5-year TLF rate (HR: 3.21, 95% CI 1.21-8.53; p = 0.019). ROC analysis showed that QFR a negative predictive value (NPV) of 89.6% ([AUC] 0.73, 95% CI 0.58-0.88, p < 0.05), the cutoff point is 0.85. The patients with a low QFR (< 0.80) in jailed LCX after LM simple crossover stenting had worse 5-year outcomes than those with a high QFR. Conversely, a QFR ≥ 0.85 of jailed LCx could serve as a good predictor of low risk of adverse outcome in LCx ostium. The QFR computation of the jailed LCx may be helpful to determine whether an additional procedure is required for the jailed side branch.

Side Branch Late Thrombosis After Left Main Coronary Artery Crossover Stenting

Background

With the established use of crossover stenting technique in bifurcation coronary artery lesions, added clinical benefit of final kissing of the side branch remains debatable. We report a case of a stenosis and thrombus formation of an ostial side branch after crossover stenting.

Case Summary

A 38-year-old man was admitted with acute coronary syndrome complicated by acute pulmonary oedema. He was treated with stenting of the left descending artery (LAD) into the left main coronary artery (LMCA) 12 months earlier. Coronary angiography showed a filling defect in the ostial left circumflex coronary artery (LCX). Optical coherence tomography revealed neointimal growth of the LAD stent resulting in narrowing the LCX orifice and a large thrombus behind stent struts. After treatment of the lesion and optimised implantations of drug-eluting stents, the patient was transferred to the intensive care unit and monitored closely. Given his advanced ischaemic cardiomyopathy, the patient is being evaluated for heart transplantation eligibility.

Discussion

Stent struts across a bifurcated major side branch after crossover stenting could risk late stenosis and thrombus formation of the side branch. The clinical usefulness of routine imaging-guided kissing techniques even with good angiographic results in these cases should be evaluated.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40119-022-00270-w.

Impact of intravascular ultrasound and final kissing balloon dilatation on long-term clinical outcome in percutaneous revascularization with 1-stent strategy for left main coronary artery stenosis in drug-eluting stent era

BACKGROUND

It remains uncertain whether intravascular ultrasound (IVUS) use and final kissing balloon (FKB) dilatation would be standard care of percutaneous coronary intervention (PCI) with a simple 1-stent technique in unprotected left main coronary artery (LMCA) stenosis. This study sought to investigate the impact of IVUS use and FKB dilatation on long-term major adverse cardiac events (MACEs) in PCI with a simple 1-stent technique for unprotected LMCA stenosis.

METHODS

Between June 2006 and December 2012, 255 patients who underwent PCI with 1 drug-eluting stent for LMCA stenosis were analyzed. Mean follow-up duration was 1663 ± 946 days. Long-term MACEs were defined as death, nonfatal myocardial infarction (MI) and repeat revascularizations.

RESULTS

During the follow-up, 72 (28.2%) MACEs occurred including 38 (14.9%) deaths, 21 (8.2%) nonfatal MIs and 13 (5.1%) revascularizations. The IVUS examination and FKB dilatation were done in 158 (62.0%) and 119 (46.7%), respectively. IVUS use (20.3 versus 41.2%; log-rank P < 0.001), not FKB dilatation (30.3 versus 26.5%; log-rank P = 0.614), significantly reduced MACEs. In multivariate analysis, IVUS use was a negative predictor of MACEs [hazards ratio 0.51; 95% confidence interval (CI) 0.29-0.88; P = 0.017], whereas FKB dilatation (hazard ratio 1.68; 95% CI, 1.01-2.80; P = 0.047) was a positive predictor of MACEs. In bifurcation LMCA stenosis, IVUS use (18.7 versus 48.0%; log-rank P < 0.001) significantly reduced MACEs. In nonbifurcation LMCA stenosis, FKB dilatation showed a trend of increased MACEs (P = 0.076).

CONCLUSION

IVUS examination is helpful in reducing clinical events in PCI for LMCA bifurcation lesions, whereas mandatory FKB dilatation after the 1-stent technique might be harmful in nonbifurcation LMCA stenosis.

Towards a common pathway for the treatment of left main disease: contemporary evidence and future directions: Left main disease treatment

There is increasing evidence to support percutaneous treatment of left main (LM) disease. Due to its major clinical impact, any procedure in the left main should be meticulously planned and performed. In this review, we aim to integrate the available evidence into a common treatment pathway, starting with understanding the distinct anatomical features of the left main. A three-level decision-making process is presented. First, in instances of angiographic ambiguity, intravascular ultrasound and fractional flow reserve can be used to decide if revascularisation could be deferred. Second, if revascularisation is indicated, the risks and benefits of percutaneous versus surgical procedures should be evaluated. Third, if percutaneous coronary intervention (PCI) is chosen, the operator should decide between the provisional single-stent versus upfront two-stent strategies. Regardless of the PCI technique selected, it should be performed according to the recommendations of a stepwise procedure utilising proximal optimisation (POT) after each instance of crossover stenting and kissing balloon inflation (KBI) where necessary. In addition to the recognised quality markers such as POT and KBI, we discuss the clinical relevance of the operator's LM PCI experience and the intracoronary imaging guidance when treating patients with left main disease.

Optimal strategy for side branch treatment in patients with left main coronary bifurcation lesions

INTRODUCTION AND OBJECTIVES

There are no guidelines regarding the most appropriate approach for provisional side branch (SB) intervention in left main (LM) bifurcation lesions.

METHODS

The present prospective, randomized, open-label, multicenter trial compared conservative vs aggressive strategies for provisional SB intervention during LM bifurcation treatment. Although the trial was designed to enroll 700 patients, it was prematurely terminated due to slow enrollment. For 160 non-true bifurcation lesions, a 1-stent technique without kissing balloon inflation was applied in the conservative strategy, whereas a 1-stent technique with mandatory kissing balloon inflation was applied in the aggressive strategy. For 46 true bifurcation lesions, a stepwise approach was applied in the conservative strategy (after main vessel stenting, SB ballooning when residual stenosis> 75%; then, SB stenting if residual stenosis> 50% or there was a dissection). An elective 2-stent technique was applied in the aggressive strategy. The primary outcome was a 1-year target lesion failure (TLF) composite of cardiac death, myocardial infarction, or target lesion revascularization.

RESULTS

Among non-true bifurcation lesions, the conservative strategy group used a smaller amount of contrast dye than the aggressive strategy group. There were no significant differences in 1-year TLF between the 2 strategies among non-true bifurcation lesions (6.5% vs 4.9%; HR, 1.31; 95%CI, 0.35-4.88; P=.687) and true bifurcation lesions (17.6% vs 21.7%; HR, 0.76; 95%CI, 0.20-2.83; P=.683).

CONCLUSIONS

In patients with a LM bifurcation lesion, conservative and aggressive strategies for a provisional SB approach have similar 1-year TLF rates.

Toward a sequential provisional coronary bifurcation stenting technique. From kissing balloon to re-POT sequence

The specific anatomy of coronary bifurcations makes them prime sites of atherogenesis and complicates revascularization. Account must be taken of the systematic difference in diameter between the 3 constituent vessels so as to minimize final side-branch ostium obstruction and maintain the law of conservation of flow, while respecting the bifurcation angles. Kissing balloon inflation (KBI) was long recommended, but never clearly demonstrated clinical benefit in single-stent provisional stenting. The detrimental proximal overstretch induced by simultaneous inflation of balloons, observed clinically and confirmed experimentally, probably explains this inefficacy. Advances in knowledge of bifurcation pathophysiology and experimental bench studies gradually led to the development of a new purely sequential technique, re-POT, without balloon juxtaposition, comprising 3 successive steps: (1) initial "proximal optimization technique" (POT), (2) side-branch opening, and (3) final POT. In contrast to KBI, re-POT has been progressively assessed from bench to first clinical study. The aim of the present review is to present the pathophysiological specificities of coronary bifurcations, and some explanations for the failure of KBI which led to the development of a new purely sequential coronary bifurcation provisional stenting strategy, based on re-POT.

Prognostic impact of final kissing balloon technique after crossover stenting for the left main coronary artery: from the AOI-LMCA registry

It is still uncertain whether the final kissing balloon technique (FKBT) is mandatory after crossover stenting for the left main coronary artery (LMCA). Assessing Optimal Percutaneous Coronary Intervention for LMCA (AOI-LMCA) registry, a 6-center retrospective registry, enrolled 1809 consecutive patients for LMCA stenting in Japan. In the present analysis, 5-year clinical outcomes were compared between non-FKBT (n = 160) and FKBT (n = 578) groups in patients treated with crossover stenting with drug-eluting stents from the LMCA to the left anterior descending artery. Propensity score-matched analysis was also performed in 160 patient pairs. In the entire study population as well as in the propensity-matched population, the cumulative 5-year incidence of the primary outcome measure (target lesion revascularization: TLR) was not significantly different between the FKBT and non-FKBT groups (10.7 versus 14.3%, P = 0.49, and 11.8 versus 14.3%, P = 0.53, respectively). In the sensitivity analysis by the multivariable Cox proportional hazard model, the effect of FKBT relative to non-FKBT for TLR remained insignificant (adjusted HR 0.89, 95% CI 0.47–1.69, P = 0.72). Regarding the TLR location, there were no significant differences in the cumulative incidences of TLR for LMCA-only, for the main branch, and for the side branch between the 2 groups (2.2 versus 1.3%, P = 0.93, 11.8 versus 9.1%, P = 0.71, and 8.2 versus 7.6%, P = 0.82, respectively). FKBT after a 1-stent strategy for LMCA crossover stenting did not affect TLR and other clinical outcomes during 5-year follow-up.

Clinical Trial Registration: Assessing Optimal Percutaneous Coronary Intervention for Left Main Coronary Artery Stenting Registry (AOI LMCA Stenting Registry). http://www.umin.ac.jp/ctr/index/htm/. Unique Identifier: UMIN000014706.

Final kissing balloon inflation for coronary bifurcation lesions treated with single-stent technique : A meta-analysis

BACKGROUND

The efficacy of final kissing balloon (FKB) inflation in one-stent techniques for bifurcation lesions is controversial. The goal of the present study was to investigate the impact of FKB on long-term clinical outcomes in one-stent strategies.

METHODS

A literature search of the PubMed, Embase, and Cochrane Library databases was undertaken through August 2017. The primary outcome was major adverse cardiac events (MACE), defined as the composite of cardiac death, myocardial infarction, and target lesion revascularization. Overall hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using the random-effects model.

RESULTS

Ten studies comprising 7364 patients treated with a one-stent technique were included in the analysis. Overall, FKB did not demonstrate a significant reduction in MACE compared with non-FKB in both randomized trials (HR: 1.13; 95% CI: 0.65-1.98) and observational studies (HR: 0.86; 95% CI: 0.61-1.20). The risk of cardiac death (HR: 0.89; 95% CI: 0.53-1.49), myocardial infarction (HR: 0.76; 95% CI: 0.53-1.09), and target lesion revascularization (HR: 0.96; 95% CI: 0.74-1.23) was also similar in both groups.

CONCLUSION

FKB may not be mandatory and a selective FKB strategy might be more justified in one-stent techniques for bifurcation lesions.