Interventional Therapy of Bifurcation Lesions

Percutaneous coronary intervention of bifurcation lesions

Bifurcation coronary artery disease is common as the development of atherosclerosis is facilitated by altered endothelial shear stress. Multiple anatomical and physiological factors need to be considered when treating bifurcation lesions. To achieve optimal results, various stenting techniques have been developed, each with benefits and limitations. In this state-of-the-art review we describe technically important characteristics of bifurcation lesions and summarise the evidence supporting contemporary bifurcation techniques.

Feasibility and efficacy of an ultra-short side branch-dedicated balloon in coronary bifurcation stenting

BACKGROUND

Side branch (SB) dilation with an ultra-short balloon after main vessel (MV) stenting may minimise stent failure in coronary bifurcation lesions.

AIMS

We sought to investigate the feasibility and efficacy of the Glider balloon (GB), a side branch (SB)-dedicated balloon 4 mm in length, in coronary bifurcation stenting.

METHODS

In bench testing, stent configuration was examined with micro-focus computed tomography after crossover stenting followed by GB dilation or kissing balloon inflation (KBI). In the clinical study we performed GB dilatation after MV stenting for 207 lesions in 194 patients. Failure of the GB dilation and additional procedures due to inducible stent failure were investigated as well as adverse cardiac events at 1-year follow-up.

RESULTS

In bench testing GB dilation maintained cross-sectional stent area without significant deformation and presented effective jailed strut removal in a high-angled bifurcation model. In the clinical study the cohort included left main, true bifurcation lesion, and two-stent treatment in 42.0%, 45.9%, and 14.0%, respectively. The proximal optimisation technique (POT) or POT-like inflation was performed in 82.1%. GB crossing failure, SB stenting due to dissection, and stent deformation requiring correction by KBI or MV dilation occurred in 8.7%, 1.4%, and 5.8%, respectively. Finally, simple GB dilation without KBI was completed in 91.8% for SB dilation. At one-year follow-up, target lesion revascularisation, cardiac death, myocardial infarction, and stent thrombosis were found in 7.2%, 2.1%, 2.1%, and 1.0%, respectively.

CONCLUSIONS

Simple GB dilation after adequate expansion of the proximal MV stent provided acceptable acute and long-term results as an alternative to KBI.

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.

Procedural and Clinical Outcomes in Management of Bifurcational Lesions in ST Elevation Myocardial Infarction

BACKGROUND

Bifurcation percutaneous coronary intervention (PCI) remains a challenging frontier in interventional cardiology, especially in the setting of ST-elevation myocardial infarction (STEMI). We examined the procedural and clinical outcomes of this patient subset.

METHODS

We conducted a retrospective case-control study. Between February 2006 and March 2011, 129 patients with STEMI underwent bifurcation PCI at our institution. One hundred and twenty-nine (129) control STEMI patients with non-bifurcation PCI were selected from the institutional database, matched for age, gender, culprit vessel, and lesion location. Patients with cardiac arrest, cardiogenic shock, or who required mechanical ventilation were excluded. Twelve (12)-month follow-up data were collected by telephone calls and examination of the medical records.

RESULTS

The average age of patients presenting with STEMI was 61.6 ± 13.1 in the bifurcation group and 61.5 + 31.1 in the non-bifurcation group. There was no difference in lesion type, use of thrombus aspiration catheters, or glycoprotein inhibitors (GPI) among them. Also, the use of drug eluting stent (DES), total cumulative length of stent used, and diameter of the post-dilation balloon were similar. Final kissing balloon post-dilation was performed in 40.3% of bifurcation PCI cases. The incidence of procedural failure (TIMI 0 flow) was 1.5% vs. 0%; p = 0.478. At 12-months follow-up, the bifurcation PCI group had higher incidence of target lesion revascularisation (TLR) (10.9% vs. 3.9%, p = 0.050), mortality (10.1% vs. 2.3%, p = 0.020), and stent thrombosis (9.3% vs. 1.6%; p = 0.013); comprising one acute, nine subacute, and two late vs. two subacute stent thromboses.

CONCLUSIONS

During acute STEMI, bifurcation PCI has excellent acute procedural outcomes, but significantly increased incidence of TLR, stent thrombosis and mortality at 12 months.

Concept and practice of transradial 5 French percutaneous treatment of coronary bifurcation lesions

OBJECTIVES

To assess the efficacy and safety of transradial 5 French percutaneous treatment of coronary bifurcations using conventional devices.

BACKGROUND

Radial artery is smaller than femoral artery, and its size may potentially limit transradial intervention, especially when coronary anatomy is not known.

METHODS

Patients with bifurcations lesions undergoing transradial 5 French ad hoc revascularization were treated according to provisional side branch (SB) stenting followed by the POT-SB dilation-final POT sequence. Only conventional devices were used.

RESULTS

Overall, 80 patients (58 men, 65 ± 10 years) were enrolled. True bifurcations accounted for 64% of cases, with the left anterior descending artery/diagonal branch being the most frequent bifurcation site (n = 37, 46%) and left main coronary artery bifurcation being treated in 6 (8%) patients. Angiographic success was achieved in 78 (97.5%) patients through a 5 French guiding catheter whereas in two cases, a 5-6 French guiding catheter upgrade was required to optimize SB treatment after the main bifurcation vessel have been secured. Overall, procedural success was achieved in all but one patient who had periprocedural necrosis following multivessel PCI. Another patient underwent target bifurcation revascularization because of a critical restenosis in a significant SB yielding an acute coronary syndrome five months after the index procedure.

CONCLUSIONS

This study demonstrates the feasibility of transradial 5 French bifurcation intervention with nondedicated devices and preliminary supports its efficacy and safety over a wide range of bifurcation anatomy and complexity.

Treatment strategies for coronary bifurcation lesions made easy in the current era by introduction of the BIFURCAID app

Coronary bifurcation lesions account for 15-20% of all percutaneous coronary interventions. Percutaneous revascularization of these lesions is technically challenging and results in lower success rates than nonbifurcation lesions. There are unique procedural considerations and techniques that are employed in the percutaneous revascularization of these lesions. Our objective is to define the procedural complexities of treating coronary bifurcation lesions and describe the leading provisional and dedicated two stent techniques used to optimize procedural and clinical results, as described in the BIFURCAID app.

Should kissing balloon inflation after main vessel stenting be routine in the one-stent approach? A systematic review and meta-analysis of randomized trials

The KBI (kissing balloon inflation) technique is considered the default strategy for the two-stent approach in real world practice. Studies comparing KBI and No-KBI in patients undergoing the one-stent approach have reported conflicting results. The meta-analysis was performed to compare the clinical outcomes of the KBI strategy and the No-KBI strategy for coronary bifurcation lesions in the one-stent approach. Five randomized studies were included, and a total of 1264 patients were involved in the meta-analysis. The primary outcome was cardiac death. The secondary end points were stent thrombosis, MI (myocardial infarction), target lesion revascularization (TLR), target vessel revascularization (TVR), and main vessel and side branch restenosis. Compared with the No-KBI strategy, the KBI strategy was associated with a significant reduction in side branch restenosis (OR: 0.44, 95% CI: 0.30–0.64, p<0.001). A high risk of main vessel restenosis was found in the KBI group (OR: 2.96, 95% CI: 1.74–5.01, p<0.001). There were no significant differences in rates of cardiac death (OR: 1.89, 95% CI: 0.60–5.95, p = 0.28), stent thrombosis (OR: 0.98, 95% CI: 0.19–4.94, p = 0.98), MI (OR: 0.68, 95% CI: 0.33–1.44, p = 0.30), TLR (OR 1.14, 95% CI 0.68–1.90, p = 0.62), or TVR (OR 1.27, 95% CI 0.75–2.16, p = 0.38). Compared with the No-KBI strategy, the KBI strategy reduced the incidence of side branch restenosis and increased the risk of main branch restenosis in the one-stent approach. However, the clinical outcomes were similar between the KBI and No-KBI groups.

Benefit of a new provisional stenting strategy, the re-proximal optimisation technique: the rePOT clinical study

AIMS

A new coronary bifurcation provisional stenting technique without kissing balloon, rePOT, associating the proximal optimisation technique (POT), side branch inflation and final POT, showed excellent mechanical results in a bench test. The present study sought to use optical coherence tomography (OCT) to quantify the mechanical results of rePOT in vivo in a large patient sample with complex coronary bifurcations.

METHODS AND RESULTS

A total of 106 patients with coronary bifurcations were included in a multicentre prospective registry (left main, 40.6%; true Medina bifurcation, 39.6%). Three OCT runs were performed, at baseline, just after stent implantation and after the complete rePOT sequence, quantifying global malapposition, side branch obstruction (SBO), and various geometric arterial criteria. RePOT was completed systematically. RePOT significantly reduced global strut malapposition from 18.9±13.4% just after stent implantation to 3.2±3.9% (p<0.05), residual SBO from 44.3±12.9% to 17.0±14.3% (p<0.05), and ellipticity index from 1.19±0.11 to 1.13±0.12 (p<0.05). Exhaustive six-month follow-up found only one mother-vessel target lesion revascularisation.

CONCLUSIONS

This clinical study of a large sample of complex coronary bifurcations with OCT analysis showed the benefit of the rePOT sequence in provisional stenting, replicating in vivo the excellent in vitro geometric results previously reported, and confirming ease of implementation and medium-term safety.

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.

Contemporary Approach to Coronary Bifurcation Lesion Treatment

Coronary bifurcations are frequent and account for approximately 20% of all percutaneous coronary interventions. Nonetheless, they remain one of the most challenging lesion subsets in interventional cardiology in terms of a lower procedural success rate and increased rates of long-term adverse cardiac events. Provisional side branch stenting should be the default approach in the majority of cases and we propose easily applicable and reproducible stepwise techniques associated with low risk of failure and complications.

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

The role of final kissing balloon (FKB) inflation after simple crossover stenting in unprotected left main (LM) bifurcation stenosis remains unknown. From the Asan Medical Center-Left Main Revascularization (ASAN-MAIN) registry, 413 patients with LM bifurcation stenosis treated by simple crossover stenting with a drug-eluting stent were identified. After simple crossover stenting, FKB inflation was performed in 95 patients (FKB group) and 318 patients finished the procedure without FKB (no-FKB group). The primary end points of the 2-year incidence of major adverse cardiac events (death, myocardial infarction, and left main target lesion revascularization [LM-TLR]) were similar between the FKB and no-FKB groups (12.5% vs 8.5%, p = 0.24). After adjustment, the risk of major adverse cardiac event was not significantly different between the FKB and the no-FKB groups (hazard ratio [HR] 1.10, 95% confidence interval [CI] 0.49 to 2.49; p = 0.82). The risk of death (HR 1.03, 95% CI 0.28 to 3.82; p = 0.98), the composite of death or myocardial infarction (HR 0.95, 95% CI 0.26 to 3.51; p = 0.96), or LM-TLR (HR 1.32, 95% CI 0.46 to 3.75; p = 0.60) were not significantly different between groups. In conclusions, for the treatment for LM bifurcation stenosis, selective, not mandatory, FKB strategy after simple crossover stenting appears to be associated with a favorable outcome.

The Proximal Optimisation Technique for Intervention of Coronary Bifurcations

The proximal optimisation technique (POT) has been proposed as a strategy to improve the results of stent scaffolding of bifurcation lesions. It is a straightforward technique whereby a short, appropriately-sized balloon is inflated in the main vessel just proximal to the carina. The technique has several advantages: it reduces the risk of side branch compromise related to shifting of the carina, it improves stent apposition in the proximal main vessel, and it facilitates side branch access after main vessel stent implantation. When treating bifurcations, final kissing balloon dilation (KBD) has traditionally been used routinely to optimise angiographic results. However, recent clinical data have questioned this philosophy and bench models have demonstrated several shortcomings of KBD. Instead, the optimal strategy may centre on performing POT, followed by side branch dilation, and completed with a final (re)-POT. The following review article describes how to perform POT and presents the evidence to support its' routine use.

Efficacy of kissing balloon inflation after provisional stenting in bifurcation lesions guided by intravascular ultrasound: short and midterm results of the J-REVERSE registry

AIMS

Our aim was to investigate the efficacy of the kissing balloon technique (KBT) in the provisional stenting of bifurcation lesions guided by intravascular ultrasound.

METHODS AND RESULTS

In the J-REVERSE registry, 300 non-left main bifurcation lesions in 299 patients were divided into two groups, KBT (n=163) and non-KBT (n=137). Patient and lesion characteristics were similar except for a higher prevalence of diabetic patients in the non-KBT group. The major adverse cardiac events (MACE) incidence at nine-month follow-up, including target lesion revascularisation, myocardial infarction, stent thrombosis, and death, was 6.3% in the KBT group versus 9.1% in the non-KBT group (p=0.47). Regardless of more SB dissection (10.5% vs. 1.5%, p=0.001), the KBT group obtained a greater luminal volume in the proximal main vessel (MV) (7.8±2.3 vs. 7.0±2.0 mm3/mm, p=0.006), maintained larger minimal lumen diameter at follow-up (2.73±0.43 vs. 2.63±0.39 mm, p=0.04), and demonstrated less binary side branch (SB) restenosis (9.7% vs. 21.0%, p=0.0004), which was beneficial for both true and non-true bifurcation lesions. Multivariate analysis showed the efficacy of KBT on SB restenosis (OR 0.28, 95% CI: 0.12-0.62, p=0.002).

CONCLUSIONS

Although the KBT increased SB dissection, it provided greater luminal gain in the proximal MV and SB with a similar MACE rate to non-KBT treatment up to nine-month follow-up.

Comparative Case-Control analysis of a dedicated self-expanding Biolimus A9-eluting Bifurcation stent versus provisional or mandatory side branch intervention strategies in the treatment of coronary bifurcation lesions

BACKGROUND

In a number of coronary bifurcation lesions, both the main vessel and the side branch (SB) need stent coverage.

OBJECTIVES

To analyze the procedural performance and the impact on radiation times (RT) and contrast medium consumption (CMC) of the Axxess™ stent system (Biosensors, Switzerland) treating de novo bifurcation lesions (DBL).

METHODS

One hundred and ten consecutive prospectively enrolled cases (Axxess Group) and 110 age, sex, and lesion location matched controls undergoing mandatory (Group A, n = 56) or provisional (Group B, n = 54) SB intervention were analyzed.

RESULTS

Although more pre-dilatation was performed in the Axxess Group (92.7% vs. 46.4% [Group A] vs. 24.1% [Group B]), and more stents were used (2.4 vs. 1.2 vs. 1.05), RT and CMC were significantly lower in the Axxess Group [7.9 min/129 ml vs. 14.2 min/209 ml vs. 7.8 min/152 ml; P < 0.001]. Final Thrombolysis In Myocardial Infarction three flow in both branches was significantly more frequent in the Axxess Group (98.2% vs. 94.6% vs. 88.9%; P = 0.02), and post-interventional troponin T elevations were the lowest in the Axxess Group. Eighty one percent of the Axxess-stents could be implanted without technical difficulties. Difficult implantations procedures were mainly related to coronary anatomy. There was no safety concerns (cardiac death, stent-thrombosis) compared to controls. Cumulative 6-months MACE rates were 11% versus 23% versus 25%. TLR rates at 6-months were 5%, 18%, and 15%, respectively.

CONCLUSIONS

Axxess bifurcation stent system procedures were associated with significantly less RT and CMC compared to conventional DBL therapy strategies. Difficult coronary anatomy may hinder successful implantation and a learning curve has to be considered. © 2016 Wiley Periodicals, Inc.

Comparative Analysis of Sequential Proximal Optimizing Technique Versus Kissing Balloon Inflation Technique in Provisional Bifurcation Stenting: Fractal Coronary Bifurcation Bench Test

OBJECTIVES

This study used a fractal bifurcation bench model to compare 6 optimization sequences for coronary bifurcation provisional stenting, including 1 novel sequence without kissing balloon inflation (KBI), comprising initial proximal optimizing technique (POT) + side-branch inflation (SBI) + final POT, called "re-POT."

BACKGROUND

In provisional bifurcation stenting, KBI fails to improve the rate of major adverse cardiac events. Proximal geometric deformation increases the rate of in-stent restenosis and target lesion revascularization.

METHODS

A bifurcation bench model was used to compare KBI alone, KBI after POT, KBI with asymmetric inflation pressure after POT, and 2 sequences without KBI: initial POT plus SBI, and initial POT plus SBI with final POT (called "re-POT"). For each protocol, 5 stents were tested using 2 different drug-eluting stent designs: that is, a total of 60 tests.

RESULTS

Compared with the classic KBI-only sequence and those associating POT with modified KBI, the re-POT sequence gave significantly (p < 0.05) better geometric results: it reduced SB ostium stent-strut obstruction from 23.2 ± 6.0% to 5.6 ± 8.3%, provided perfect proximal stent apposition with almost perfect circularity (ellipticity index reduced from 1.23 ± 0.02 to 1.04 ± 0.01), reduced proximal area overstretch from 24.2 ± 7.6% to 8.0 ± 0.4%, and reduced global strut malapposition from 40 ± 6.2% to 2.6 ± 1.4%.

CONCLUSIONS

In comparison with 5 other techniques, the re-POT sequence significantly optimized the final result of provisional coronary bifurcation stenting, maintaining circular geometry while significantly reducing SB ostium strut obstruction and global strut malapposition. These experimental findings confirm that provisional stenting may be optimized more effectively without KBI using re-POT.

Comparison of failure rates of crossing side branch with pressure vs. coronary guidewire: a meta-analysis

OBJECTIVES

The aim of this study was to compare the failure rates of crossing side branch (SB) with pressure guidewire vs. coronary guidewire after main vessel (MV) stenting in coronary bifurcation lesions (CBL).

BACKGROUND

Percutaneous coronary intervention of CBL is technically difficult. The European Bifurcation Club recommends performing either fractional flow reserve (FFR) estimation of the SB or final kissing balloon inflation (FKBI) after the MV stenting when a significant SB ostial stenosis is present. Even though FFR is recommended in CBL, there is concern about SB crossing with pressure guidewire among interventionists.

MATERIALS AND METHODS

We undertook a comprehensive literature search to identify all relevant studies reporting the failure rates of SB crossing after MV stenting with either pressure or coronary guidewire. A random effects model was used to compare the failure rates between the two approaches.

RESULTS

Our search identified six studies that reported failure rates of SB crossing with a pressure guidewire (n = 648) and 11 studies that reported failure rates of SB crossing with a coronary guide-wire (n = 2601). Estimated pooled failure rate was 3·9% (95% CI: 1·5% to 9·6%) for inability to cross SB with pressure guidewire. Estimated pooled failure rate of SB crossing with coronary guidewire was 3·1% (95% CI: 1·5% to 6·2%). There was no significant difference between the failure rates in the two groups (P = 0·70).

CONCLUSION

The failure rates of SB crossing after MV stenting are low with both pressure and coronary guidewire procedures, with no significant difference between the two approaches.

Percutaneous Coronary Intervention for Bifurcation Lesions

This article summarizes treatment alternatives for coronary bifurcation lesions. It also reviews current definitions and classifications pertaining to bifurcation lesions and provides an overview of the impact of bifurcation lesions on clinical outcomes.

Optimal kissing balloon inflation after single-stent deployment in a coronary bifurcation model

AIMS

To define the optimal kissing balloon inflation (KBI) after single-stent deployment in a coronary bifurcation model.

METHODS AND RESULTS

We deployed stents in main vessels (MV) followed by KBI in various conditions and compared the stent configurations. A) KBI at the operator's discretion vs. under the guidelines of minimal balloon overlapping (MBO). Various stent configurations were observed after the former option, whereas similar maximal dilation points were observed under the MBO guidelines. B) Long balloon overlapping (LBO) vs. MBO with proximal MV dilated by a large balloon. The proximal MV was dilated to an ideal round shape with MBO versus an oval shape with LBO. C) Two-link vs. 3-link stents. Although the 2-link stent was advantageous to open the side branch, it incurred a risk of overdilatation of the proximal struts, whereas the 3-link stent preserved its structure. Computed simulations of coronary flow were analysed in the following left main coronary models: circle with a diameter of 4 and 5.5 mm, ellipse with longitudinal direction and tilt position. They revealed that the overdilated side was exposed to low shear stress regardless of its shape.

CONCLUSIONS

Optimal KBI can be achieved with MBO and proximal dilatation by an optimally sized balloon.

Final kissing balloon inflation: the whole story

Final kissing balloon inflation (KBI) after provisional bifurcation stenting has failed to provide clear clinical benefit except for a decrease in side branch stenosis, while a significant reduction of major adverse cardiac events has been documented in two-stent deployment. The optimisation of KBI in terms of proximal optimisation technique, appropriate guidewire re-crossing, minimal balloon overlapping, and balloon size selection may overcome the drawbacks of conventional KBI by: 1) correcting the proximal malapposition expected from fractal geometry; 2) optimising side branch ostium strut opening while conserving a bifurcation area free of malapposition at both the carina and the side branch ostium; and 3) optimising the geometry, velocity fields and shear rate.

Randomized Comparison of FFR-Guided and Angiography-Guided Provisional Stenting of True Coronary Bifurcation Lesions: The DKCRUSH-VI Trial (Double Kissing Crush Versus Provisional Stenting Technique for Treatment of Coronary Bifurcation Lesions VI)

OBJECTIVES

This study sought to compare the outcomes of fractional flow reserve (FFR)-guided and angiography (Angio)-guided provisional side-branch (SB) stenting for true coronary bifurcation lesions.

BACKGROUND

Angio-guided provisional SB stenting after stenting of the main vessel provides favorable outcomes for the majority of coronary bifurcation lesions. Whether an FFR-guided provisional stenting approach is superior has not been studied.

METHODS

A total of 320 patients with single Medina 1,1,1 and 0,1,1 coronary bifurcation lesions undergoing stenting with a provisional SB approach were randomly assigned 1:1 to Angio-guided and FFR-guided groups. SB stenting was performed for Thrombolysis In Myocardial Infarction flow grade<3, ostial SB stenosis>70%, or greater than type A dissection after main vessel stenting in the Angio-guided group and for SB-FFR<0.80 in the FFR-guided group. The primary endpoint was the 1-year composite rate of major adverse cardiac events (cardiac death, myocardial infarction, and clinically driven target vessel revascularization).

RESULTS

Comparing the Angio-guided and FFR-guided groups, treatment of the SB (balloon or stenting) was performed in 63.1% and 56.3% of lesions respectively (p=0.07); stenting of the SB was attempted in 38.1% and 25.9%, respectively (p=0.01); and, when attempted, stenting was successful in 83.6% and 73.3% of SBs, respectively (p=0.01). The 1-year composite major adverse cardiac event rate was 18.1% in both groups (hazard ratio: 0.91, 95% confidence interval: 0.48 to 1.88; p=1.00). The 1-year target vessel revascularization and stent thrombosis rates were 6.9% and 5.6% (p=0.82) and 1.3% and 0.6% (p=0.56) in the Angio-guided and FFR-guided groups, respectively.

CONCLUSIONS

In this multicenter, randomized trial, angiographic and FFR guidance of provisional SB stenting of true coronary bifurcation lesions provided similar 1-year clinical outcomes. (Randomized Study on DK Crush Technique Versus Provisional Stenting Technique for Coronary Artery Bifurcation Lesions; ChiCTR-TRC-07000015).

Coronary bifurcation lesions: Present status and future perspectives

Coronary bifurcation lesions (CBLs) are challenging and associated with a higher rate of adverse events than non-bifurcation lesions. In the era of drug-eluting stents, 2 primary interventional strategies for treating CBL include the complex strategy the main vessel (MV) and side-branch (SB) stenting, and the simple strategy MV stenting combined with provisional SB stenting. The meta-analysis of the simple vs. complex strategies demonstrated an increased incidence of myocardial infarction in the complex strategy. Likewise, the Tryton dedicated bifurcation stents, as compared with the simple strategy, increased the rate of myocardial infarction. In contrast, the Nordic-Baltic Bifurcation Study IV demonstrated that event rates were not significantly different comparing the simple vs. complex strategies in true bifurcation lesions involving a large SB. Fractional flow reserve (FFR) has emerged as a powerful catheter based tool for the functional assessment of a stenosis, but the role of FFR on the long-term outcomes of patients with CBL has not been studied. Given the recent evidence that Tryton stents (a dedicated bifurcation stent) increased event rates, and the lack of benefit from using 2-stent techniques (the Nordic Baltic Bifurcation Study IV) in true CBL, assessing the FFR of the SB seems now of outmost importance, but randomized data are lacking. An intravascular study showed that kissing balloon inflation (KBI) significantly reduced SB stenosis, restored stent lumen at the carina, and expanded stent in the proximal segment. However, a recent randomized study showed no significant benefit of routine KBI. This review highlights current concepts and future perspectives in patients with CBL.

Assessment of side branch predilation before a provisional T-stent strategy for bifurcation lesions. A randomized trial

BACKGROUND

A simple approach is the predominant strategy for the percutaneous coronary intervention of bifurcation lesions. Performing side branch (SB) predilation in this context is currently a matter of controversy. In this study, we assess the efficacy of SB predilatation before a provisional T-stent strategy for bifurcation lesions.

METHODS

Between February 2009 and November 2012, 372 patients with true bifurcation lesions were randomized to either predilation of the SB (n = 187) or no predilatation (n = 185) before main branch (MB) stent implantation and a subsequent SB provisional stent strategy.

RESULTS

There were no significant differences between the patient groups regarding the baseline characteristics. After MB stent implantation, the TIMI flow of the SB was higher in the patients with SB predilation: TIMI flow 0 to 1; 2 (1%) versus 18 (10%), P < .001; and TIMI flow III; 179 (96%) versus 152 (82%), P < .001. Side branch stenting rates were 4% versus 3%, P = not significant. In addition, 60 patients (32%) from the SB predilation group presented SB residual stenosis by visual inspection <50%, and TIMI flow ≥III did not require any additional treatment. The failure rate of SB rewiring, the time of rewiring, the number of wires used, and the incidence of major events were similar in both groups of patients.

CONCLUSIONS

Predilation of the SB resulted in improved TIMI flow after MB stenting and less indication to subsequently treat the SB. If rewiring of the SB is required, predilation did not hinder this maneuver.

Impact of kissing balloon inflation on the main vessel stent volume, area, and symmetry after side-branch dilation in patients with coronary bifurcation lesions: a serial volumetric intravascular ultrasound study

OBJECTIVES

Intravascular ultrasound (IVUS) was performed to investigate the impact of kissing balloon inflation (KBI) on the main vessel (MV) stent volume, area, and symmetry after side-branch (SB) dilation in patients with coronary bifurcation lesions (CBL).

BACKGROUND

It remains controversial whether KBI would restore the MV stent area and symmetry loss after SB dilation.

METHODS

A total of 88 serial IVUS examinations of the MV were performed after MV angioplasty, MV stenting, SB dilation, and KBI in 22 patients with CBL. The MV stent was divided into proximal, bifurcation, and distal segments; the stent volume index (SVI), minimal stent area (MSA), stent symmetry index (SSI), and external elastic membrane (EEM) volume index were measured in 198 stent segments and compared after MV stenting, SB dilation, and KBI.

RESULTS

In the bifurcation segment, SVI, MSA, and SSI were significantly smaller after SB dilation than after MV stenting and KBI (SVI was 6.10 ± 1.50 mm(3)/mm vs. 6.68 ± 1.60 mm(3)/mm and 6.57 ± 1.60 mm(3)/mm, respectively, p < 0.05; MSA was 5.15 ± 1.30 mm(2) vs. 6.08 ± 1.40 mm(2) and 5.86 ± 1.50 mm(2), respectively, p < 0.05; and SSI was 0.78 ± 0.02 mm(2) vs. 0.87 ± 0.03 mm(2) and 0.84 ± 0.03 mm(2), respectively, p < 0.05). KBI restored the MV SVI, MSA, and SSI after SB dilation. In the proximal segment, SVI, MSA, and EEM volume index were significantly larger, but SSI was smaller after KBI than after MV stenting and SB dilation. In the distal segment, neither SB dilation nor KBI had a significant impact on the MV stent volume or symmetry.

CONCLUSIONS

This is the first comprehensive volumetric IVUS analysis of CBL, to our knowledge, demonstrating that KBI restores the MV stent volume, area, and symmetry loss after SB dilation in the bifurcation segment, and induces asymmetric stent expansion in the proximal segment.

Treatment of coronary bifurcation lesions: stent-covering of the side branch with and without PCI of the side branch: a retrospective analysis of all consecutive patients

Background

Treatment of coronary bifurcation lesions is a complex problem.

Methods

This retrospective single-center study included all consecutive patients with PCI of coronary bifurcations with stent covering of the side branch (SB) between January 2008 - August 2011.

Two methods were compared: group A represented patients without treatment of SB, group B were patients with treatment of SB.

Results

Our study group (n = 98) was group A (n = 64, 65.3%) and group B (n = 34, 34.7%). Mean follow-up was 14.1 (group A) vs 12.3 (group B, p = ns) months.

Mean age (years) was 70.3 (group A) vs. 67.0 (group B, p = ns), NSTEMI/STEMI was present in 54.7% (group A) vs. 41,2% (group B, p = ns).

Duration of x-raying (min, group A vs group B) and the amount of contrast medium (ml) were significantly lower in group A: 18.1 min vs 20.1 min and 225.8 ml vs 307.4 ml (p < 0.05).

Final TIMI flow III inside the MB was reached in 98.4% (group A) vs. 97.1% (group B, p = ns), inside the SB in 84.4% vs. 94.1% (p = ns).

Target lesion revascularization and target vessel revascularization was seen in 15.9% (group A) vs 32.4% (group B, p = 0.07), cardiac death in 7.9% (group A) vs 14.7% (group B, p = 0.3).

All MACE revealed were: 23.8% (group A) vs. 47.1% (group B, p = 0.02).

Conclusion

In patients with coronary bifurcations a simpler strategy has a significantly lower MACE.

Trial registration

ClinicalTrials.gov Identifier: NCT01538186

A novel technique in the use of fractional flow reserve in coronary artery bifurcation lesions

The side branch (SB) in bifurcation lesions is a frequently encountered challenge that interventional cardiologists must face. There is great interest in determining fractional flow reserve (FFR) in the SB to help guide treatment decisions; however, difficulty with the pressure guidewire limits its widespread use. We propose a novel technique that will ease the incorporation of FFR in routine evaluation of bifurcation lesions, and allow better assessment of provisional stenting and need for SB intervention. Conventionally, to measure SB FFR, the jailed SB is re-crossed through the stent strut using a pressure wire. Our technique involves the use of a microcatheter and wire exchange within the SB, thereby alleviating some of the technical difficulties associated with the FFR wire. In light of the difficulties and clinical concerns associated with bifurcation lesions, we propose an innovative method to ease the incorporation of FFR to allow better assessment of provisional stenting and need for SB intervention.

Three-year outcome of sirolimus-eluting stent implantation in coronary bifurcation lesions: the provisional side branch stenting approach versus the elective two-stent approach

AIMS

To explore optimal management strategies for bifurcation lesions with sirolimus-eluting stents (SES).

METHODS AND RESULTS

Among 12,824 patients enrolled in the j-Cypher Registry, we identified 2,122 patients with 2,250 non-left main bifurcation lesions (average age: 69 years; diabetes: 39%; acute coronary syndrome: 24%; lesion length ≥30 mm: 17%; true bifurcation: 53%) treated exclusively with SES. The majority of lesions (1,978 lesions, 88%) were treated by provisional side branch stenting approach with a 4.5% crossover rate, while the elective two-stent approach (stenting both main and side branches) was adopted in 272 lesions. The 3-year incidence of target-lesion revascularisation (TLR) was significantly higher in the elective two-stent group than in the provisional group (18.5% vs. 9.8%, p<0.0001). The incidence of definite stent thrombosis was not different between the two groups (1.3% vs. 0.61%, p=0.21). Among 1,871 lesions with main branch stenting alone, final kissing balloon dilatation (FKB) was performed in 938 lesions (50%). The incidence of TLR was not different between the two groups with or without FKB (9.9% vs. 9.2%, p=0.98).

CONCLUSIONS

The provisional approach provided a good long-term outcome in the majority of lesions with low crossover rate to the two-stent approach. Lesions treated with FKB had similar TLR outcome to those without FKB after main branch stenting alone.

Natural history of side branches jailed by drug-eluting stents

BACKGROUND

 Stent deployment across side branch (SB) ostium is common in daily practice. The present study investigated the natural history of SBs jailed by drug-eluting stents (DES).

METHODS

 The thrombolysis in myocardial infarction (TIMI) flow grades of 271 consecutive SBs jailed by DES in 196 patients was assessed immediately after the procedure and at 9 months of follow-up. Patients receiving any SB intervention were excluded.

RESULTS

Of 271 jailed SBs, occlusion occurred in 6.27% and deterioration of flow occurred in 6.27% immediately after stenting. In patients with these SB changes, periprocedural myocardial infarction was more likely than in those without (10.0% vs. 1.8%, P = 0.017), while there was no increase of cardiac death or life-threatening complications such as stent thrombosis and Q-wave myocardial infarction (Q MI) during follow-up. At 9 months, angiography showed that one-third of the initially obstructed SBs were still occluded. In contrast, flow was maintained in almost all (98.6%) SBs with early TIMI flow grade 3 and there was no delayed occlusion of these branches. Multiple regression analysis showed that lesion complexity (Medina bifurcation class, calcification, and preprocedural TIMI grade 2 flow in the SB) and technical factors (jailing by overlapping stents) were related to SB occlusion or flow deterioration.

CONCLUSIONS

 Jailed SBs showing good flow after stenting had a favorable angiographic and clinical outcome after 9 months of follow-up. However, preprocedural lesion complexity and technical factors should be considered to avoid SB occlusion/flow deterioration associated with periprocedural myocardial infarction.

Pocket related complications in 163 patients receiving anticoagulation or dual antiplatelet therapy: D-Stat Hemostat versus standard of care

BACKGROUND

Pocket hematoma is a common complication after cardiac rhythm device implantation (CRDI) in patients receiving anticoagulation or dual antiplatelet therapy (DAPT). We sought to assess the safety and effectiveness of D-Stat Flowable Hemostat ([D-Stat]-a mixture of thrombin and collagen) in these patients.

METHODS

We conducted a prospective case control study and enrolled all patients admitted for CRDI receiving anticoagulation or DAPT. Participants received either D-Stat into the pectoral pocket as an adjunct to standard of care versus the standard of care (UC) alone. The primary endpoint was a composite of hematoma needing evacuation, and pocket infection.

RESULTS

We included a total of 163 patients (mean age 72 ± 8 years). 119 (73%) were male. 82 patients (50%) received D-stat and 81 (50%) usual care; 82 patients (50%) were treated with anticoagulation, 62 patients (38%) received DAPT, and 19 patients (12%) both. The primary endpoint occurred in 12/82 patients from the D-Stat group and 3/81 patients of the control group (14.6% versus 3.7%; p=0.03). The use of D-Stat tended for a higher incidence of pocket hematoma requiring evacuation (8.5% versus 2.4%; p=0.12), and an increased rate of pocket infections (6.1% versus 1.2%; p=0.21). Postoperative Immunoglobulin E levels (86 ± 147 IU/ml (D-Stat) versus 120 ± 231 IU/ml (UC)) and increase of C-reactive protein (D-Stat: ∆19 mg/l versus UC: 14 mg/l) were similar in both groups (p=0.26 and p=0.4, respectively).

CONCLUSIONS

Administration of D-Stat does not decrease the frequency of clinically relevant pocket hematomas. The observed rate of pocket infections in the D-Stat group is a matter of concern.