Randomized study on simple versus complex stenting of coronary artery bifurcation lesions: the Nordic bifurcation study

Remote Ischemic Conditioning in Elective PCI?

This review examines the rationale for using remote ischemic conditioning (RIC) in elective percutaneous coronary intervention (PCI) to prevent procedure-related ischemia-reperfusion injury and justifies the importance of periprocedural biomarker elevation following elective PCI as a valid target for RIC. We review the evidence for the use of RIC as a treatment in this setting and document the salutary rules that must be followed to successfully translate RIC for clinical benefit.

Angiographic study of the clinical liaison of drug-eluting stent and paclitaxel-eluting balloon in unifocal side branch ostium stenosis (ASCLEPIUS)

A reliable stenting strategy for treating isolated side branch (SB) ostium stenosis is not well established. The purpose of this study was to examine the 6-month angiographic outcome of a novel technique, called the shoulder technique, on this lesion subtype. Symptomatic patients with isolated SB ostium stenosis, defined as ≥75% diameter stenosis at SB ostium and <50% diameter stenosis in main vessel (MV), were treated with paclitaxel-eluting balloon in MV and drug-eluting stent in SB using the shoulder technique. Angiographic restudy was performed at 5-9 months and clinical follow-up was scheduled regularly every 3 months. There were 46 patients of age 66 ± 12 years with male predominance (76%) recruited. Diagonal ostium (67%) was the most frequent target lesion site. The size and length of paclitaxel-eluting balloon and drug-eluting stent used in MV and SB were 3.01 ± 0.25 and 20 ± 4 mm, and 2.39 ± 0.25 and 17 ± 6 mm, respectively. Angiographic restudy was performed on 43 (93.5%) patients at 6.5 ± 1.6 months. The late loss in MV and SB were 0.04 ± 0.19 and 0.19 ± 0.32 mm, respectively. Angiographic restensosis was seen in 2 (4.7%) patients at SB, whereas no stenosis was induced in MV. Improvement of symptom was reported in 36 (78%) patients. At 1-year follow-up, no death, myocardial infarction, and stent thrombosis was observed; target vessel revascularization was performed on 3 (6.5%) patients. Treatment of isolated SB ostium stenosis using the shoulder technique is associated with a favorable short-term angiographic outcome.

Impact of branching angle on neointimal coverage of drug-eluting stents implanted in bifurcation lesions

OBJECTIVES

To investigate the impact of branching angle (BA) on neointimal coverage of drug-eluting stents (DESs) in bifurcation lesions.

BACKGROUND

Previous experimental studies indicated that BA influences the local flow turbulence and wall shear stress, which are associated with neointimal coverage of DESs.

METHODS

Fifty-five bifurcation lesions in 47 patients were evaluated by serial optical coherence tomography (OCT) before DES implantation and at follow-up. Neointimal coverage was assessed in cross-sectional OCT images containing the side branch; regions including the side branch ostium (SO) and vessel wall (VW) were assessed separately. BA was measured using angiography (Angio-BA) and longitudinal OCT imaging (OCT-BA).

RESULTS

In the SO region, a significant negative correlation was found between the uncovered strut percentage and Angio-BA or OCT-BA (r=-0.41, P=0.0024; r=-0.33, P=0.0167, respectively) and a significant positive correlation was found between Angio-BA and average neointimal thickness (r=0.31, P=0.025), whereas no correlation was observed between OCT-BA and average neointimal thickness (r=0.20, P=0.158). In the VW region, no correlation was found between Angio-BA or OCT-BA and the uncovered strut percentage or average neointimal thickness.

CONCLUSION

BA influence the neointimal coverage over DES struts in the SO at coronary bifurcation lesions, but not in those attached to the VW.

Impact of very high pressure stent deployment on angiographic and long-term clinical outcomes in true coronary bifurcation lesions treated by the mini-crush stent technique: A single center experience

Background

Percutaneous coronary intervention (PCI) for bifurcation lesions (BL) using 2 stents technique is known to be associated with high rates of procedural failure especially on the side branch (SB) mainly due to stent incomplete apposition. Stent deployment at very high pressure (SDHP) may lead to better stent expansion and apposition. However, SDHP may also be at the origin of deeper wall injury resulting into major cardiac adverse events. No data are available on evaluation of SDHP in BL treated by a mini-crush stent technique.

Methods

One hundred and thirteen consecutive patients underwent PCI for BL (Medina 1, 1, 1) using a mini-crush stent technique with SDHP defined as ≥20 atm. An angiographic follow-up was performed at 6 month and clinical follow-up was obtained at a median of 3 years.

Results

Stent deployment mean pressures were 20 ± 1.4 atm (range 20–25) in the main vessel (MV) and 20 ± 1.5 atm (range 20–25) in SB. Simultaneous final kissing balloon was used in 92% of cases. PCI was successful in 100%. Angiographic follow-up was obtained in 83% of patients. Restenosis rate was 13% (12% restenosis in the SB) with only one case (0.8%) of SB probable thrombosis. Another case of late stent thrombosis occurred at a 3 years clinical follow-up.

Conclusion

Compared with previously published studies in which stents were deployed at lower pressure, SDHP does not increase the restenosis rate in BL using mini-crush stent technique but seems to reduce the rate of stent thrombosis.

Bifurcation lesions involved in the recanalization process of coronary chronic total occlusions: Incidence, treatment and clinical implications

BACKGROUND

The presence of a bifurcation (BL) in the context of a coronary chronic total occlusion (CTO) represents an additional difficulty. This study analyzes the incidence of BLs in CTO recanalization, the treatment, predictors of bifurcation technical success and their clinical impact.

METHODS AND RESULTS

BLs with a side branch (SB) ≥2.0mm located proximally, distally or within the occluded segment were observed in 130 (33%) of 391 CTO. Provisional stenting was the strategy more frequently used (94%). Bifurcation success (stenosis <30% in main vessel and TIMI flow III in both branches) was achieved in 105 patients (81%). In the remaining 25 (19%), the TIMI flow at the SB was <III. Predictors of bifurcation success were baseline SB wiring (OR 0.01, 95% CI: 0.001-0.09; p<0.01), the absence of dissection across the bifurcation (OR 0.10, 95% CI: 0.02-0.49; p<0.01) and non-true BLs (OR 0.16, 95% CI: 0.04-0.68; p<0.05). Regarding in-hospital results, patients with final TIMI flow <III at the SB had a higher incidence of periprocedural MI (32% vs 4.8%; p<0.01). Subsequently, the rate of MI was higher in patients with CTO-BLs than in those without BLs. At follow-up, there were no differences in the event rate between CTO-BLs and non CTO-BLs (7.7% vs 9.5%, p=ns) CONCLUSIONS: BLs in CTO is a frequent finding and could be approached as regular bifurcations. The primary success was low and this was associated with a higher incidence of periprocedural MI. Baseline SB wiring was a powerful predictor of technical success.

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.

Clinical outcome of treatment with or without a final kissing balloon technique for bifurcation in-stent restenosis lesions

BACKGROUND

The treatment strategy for in-stent restenosis (ISR) with bifurcation lesions has not been well explored. We examined the clinical outcomes between final kissing balloon technique (FKBT) after stent implantation and single-stent implantation without FKBT for bifurcation ISR lesions.

METHODS

We identified 115 consecutive ISR with bifurcation lesions among 108 patients who underwent drug-eluting stent implantation. The patients were divided into the FKBT group (34 patients, 35 lesions) and the non-FKBT group (74 patients, 80 lesions).

RESULTS

Thrombolysis in myocardial infarction flow grade of side branch was significantly greater in the patients with FKBT than those without FKBT after coronary intervention (2.80±0.46 vs. 2.65±0.68, p=0.04), but this difference was attenuated and was no longer statistically significant at the time of follow-up (2.80±0.48 vs. 2.80±0.60, p=0.97). During a mean follow-up of 47.8±23.6 months, there were no significant differences in the incidence of major adverse cardiac events (MACE). In multivariate analysis, estimated glomerular filtration rate (hazard ratio: 0.96, 95% confidence interval: 0.92-0.99, p=0.02) was an independent predictor of MACE. Contrast volume (170.71±47.17ml vs. 136.46±55.56ml, p=0.002) and radiation dose (1.44±1.65Gy vs. 0.96±0.46Gy, p=0.02) were significantly higher in the FKBT group than in the non-FKBT group.

CONCLUSIONS

Single-stent implantation without FKBT may be a sufficient treatment strategy for bifurcation ISR lesions.

The Need For Dedicated Bifurcation Stents: A Critical Analysis

There is growing evidence that optimally performed two-stent techniques may provide similar or better results compared with the simple techniques for bifurcation lesions, with an observed trend towards improvements in clinical and/or angiographic outcomes with a two-stent strategy. Yet, provisional stenting remains the treatment of choice. Here, the author discusses the evidence - and controversies - concerning when and how to use complex techniques.

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.

Predictors for Side Branch Failure During Provisional Strategy of Coronary Intervention for Bifurcation Lesions (from the Korean Bifurcation Registry)

The most favored strategy for bifurcation lesion is stenting main vessel with provisional side branch (SB) stenting. This study was performed to elucidate predictors for SB failure during this provisional strategy. The study population was patients from 16 centers in Korea who underwent drug-eluting stent implantation for bifurcation lesions with provisional strategy (1,219 patients and 1,236 lesions). On multivariate analysis, the independent predictors for SB jailing after main vessel stenting were SB calcification, large SB reference diameter, severe stenosis of SB, and not taking clopidogrel. Regarding SB compromise, however, the independent predictors were true bifurcation lesion and small SB reference diameter, whereas possible predictors were parent vessel thrombus and parent vessel total occlusion. In addition, SB predilation helps us to get favorable SB outcome. The diameter of SB ostium after main vessel stenting became similar between severe SB lesions treated with predilation and mild SB lesions not treated with predilation. In conclusion, SB calcification, less clopidogrel use, large SB reference diameter, and high SB diameter stenosis are independent predictors for SB jailing, and true bifurcation and small SB reference diameter are independent predictors for SB compromise after main vessel stenting.

The fate of small side branches following drug eluting stent implantation

OBJECTIVES

Although drug eluting stents (DES) have documented convenience in bifurcation lesions, possible unfavorable effects on small side branch ostium (SBO) remain a question. We aimed to explore the effects of DES on small jailed SBs (1.5-2.25 mm) which originated from the lesion on the main vessel and were not treated with either stenting or balloon dilatation.

METHODS

Angiographic data of 107 consecutive patients (129 SB) with Medina 1,1,1 or 1,1,0 lesions were evaluated at the time of procedure and at the follow-up.

RESULTS

Of all DES used, 70 (54.7%) was sirolimus-eluting, 39 (30.5%) was paclitaxel-eluting and 20 (14.8%) was zotarolimus-eluting. The diameter of SBs was 1.84 ± 0.41 mm with a stenosis of 20.7 ± 26.6% at SBO at baseline. The lesion at the SBO had progressed after the procedure when the pre vs postprocedure values and follow-up vs pre-procedure values are compared (20.7 ± 26.6% vs 29.4 ± 27.4%; p < 0.0001 and 25.4 ± 25.1 vs 20.7 ± 26.6%; p = 0.004 respectively). A significant reduction in stenosis was revealed over the follow-up (29.4 ± 27.4 vs 25.4 ± 25.1 respectively; p = 0.013). The severity of the disease at the SBO at baseline was the only parameter that affected the severity of SB stenosis in acute, longterm and follow-up. Additional parameters with influence on SB patency at different times were female gender, stent deployment with low pressure, cTFC of the main lesion, age, cTFC of the lesion, late loss index and the preprocedure TIMI flow grade of the SB.

CONCLUSIONS

Although there was a significant deterioration of SBO immediately after stenting, follow-up data showed that the lesion at SBO improved but remained worse than baseline.

Percutaneous Coronary Intervention for Bifurcation: How Can We Outperform the Provisional Strategy?

In the era of drug-eluting stents, the provisional stenting strategy has been established as the default strategy in percutaneous coronary intervention for bifurcation lesions. However, emerging evidence shows that, in selected situations, the complex strategy of stenting both vessels regardless could reduce side-branch restenosis without penalty. In particular, the double kissing crush technique has been proven to outperform the provisional strategy and other complex strategies in randomized trials. In this review, we present the evidence comparing the 2 strategies and individual stenting techniques and discuss the roles of other optimization techniques such as final kissing balloon inflation, proximal optimization technique, intravascular ultrasonography, and optical coherence tomography. Finally, we suggest a practical approach for choosing the optimal strategy for intervention with coronary bifurcation lesions.

A Pilot Study on Culottes versus Crossover Single Stenting for True Coronary Bifurcation Lesions

BACKGROUND

The purpose of our study was to compare clinical and angiographic outcomes of planned culottes technique with that of provisional crossover single stenting in the treatment of true coronary bifurcation lesions (CBL) with drug-eluting stent (DES).

METHODS

True CBL patients (n = 104) were randomly assigned to either the provisional stenting of the side branch (crossover group) or the culottes group. Additional side branch (SB) stenting in the crossover group was required if there was thrombolysis in myocardial infarction flow ≤ 1 flow). The primary end point was the occurrence of major adverse cardiac events (MACE) at nine months, including cardiac death, myocardial infarction, target lesion/vessel revascularization and in-stent thrombosis. The secondary end point was angiographic in-segment restenosis at nine months.

RESULTS

The rate of MACE at nine months was similar between the crossover and culottes groups (7.7% vs. 7.7%, p = 1.000). Additional SB stenting in the crossover group was required in 3.8% of patients. There was one procedural occlusion of SB in the crossover group. At nine months, the rate of in-segment restenosis was similar in the parent main vessel (0% vs. 1.9%, p = 1.000), main branch (1.9% vs. 7.7%, p = 0.363) and SB (17.3% vs. 9.6%, p = 0.250) between the crossover and culottes groups, respectively.

CONCLUSIONS

This study demonstrated that there is no significant difference in cumulative MACE or in-segment restenosis between crossover and culottes groups. Larger randomized clinical trials are warranted to re-evaluate the outcomes of the provisional crossover stenting versus the culottes stenting techniques utilizing DES for true CBL.

Everolimus-eluting bioresorbable vascular scaffolds implanted in coronary bifurcation lesions: Impact of polymeric wide struts on side-branch impairment

BACKGROUND

Limited data are available on bioresorbable vascular scaffolds (BVS) performance in bifurcations lesions and on the impact of BVS wider struts on side-branch impairment.

METHODS

Patients with at least one coronary bifurcation lesion involving a side-branch ≥2mm in diameter and treated with at least one BVS were examined. Procedural and angiographic data were collected and a dedicated methodology for off-line quantitative coronary angiography (QCA) in bifurcation was applied (eleven-segment model), to assess side-branch impairment occurring any time during the procedure. Two- and three-dimensional QCA were used. Optical coherence tomography (OCT) analysis was performed in a subgroup of patients and long-term clinical outcomes reported.

RESULTS

A total of 102 patients with 107 lesions, were evaluated. Device- and procedural-successes were 99.1% and 94.3%, respectively. Side-branch impairment occurring any time during the procedure was reported in 13 bifurcations (12.1%) and at the end of the procedure in 6.5%. Side-branch minimal lumen diameter (Pre: 1.45±0.41mm vs Final: 1.48±0.42mm, p=0.587) %diameter-stenosis (Pre: 26.93±16.89% vs Final: 27.80±15.57%, p=0.904) and minimal lumen area (Pre: 1.97±0.89mm(2) vs Final: 2.17±1.09mm(2), p=0.334), were not significantly affected by BVS implantation. Mean malapposed struts at the bifurcation polygon-of-confluence were 0.63±1.11.

CONCLUSIONS

The results of the present investigation suggest feasibility and relative safety of BVS implantation in coronary bifurcations. BVS wide struts have a low impact on side-branch impairment when considering bifurcations with side-branch diameter≥2mm.

Fork in the road: Are all bifurcations created equal?

The TRYTON study evaluated routine side branch (SB) stenting with a novel bare metal stent (BMS) designed for true bifurcation lesions (Medina 1,1,1; 1,0,1; 0,1,1) and compared it to a strategy of balloon angioplasty with provisional stenting. It failed to meet the primary endpoint of non-inferiority in target vessel failure mainly driven by peri-procedural myocardial infarction (MI) with elevated CK-MB > 3× the upper limit of normal. In this substudy, 41% of patients who had a SB diameter > 2.25 mm were evaluated and the new stent was found to be non-inferior in the primary outcome of target vessel failure with no difference in post-procedural MI. This substudy suggests that appropriately sized SB stents with TRYTON may be useful when the SB is >2.25 mm in diameter. However, further studies could evaluate routine use of FFR for SBs; drug eluting versions of the stent as well as stents designed for vessels 2.25 mm in diameter which are frequently felt to be clinically larger when not subjected to core lab analysis.

The role of age and comorbidities in postoperative outcome of mitral valve repair: A propensity-matched study

The average age of patients undergoing mitral valve repair is increasing each year. This retrospective study aimed to compare postoperative complications of mitral valve repair (known to be especially high-risk) between 2 age groups: under and over the age of 80.Patients who underwent mitral valve repair were divided into 2 groups: group 1 (<80 years old) and group 2 (≥80 years old). Baseline characteristics, pre- and postoperative hemodynamic data, surgical characteristics, and postoperative follow-up data until hospital discharge were collected.A total of 308 patients were included: 264 in group 1 (age 63 ± 13 years) and 44 in group 2 (age 83 ± 2 years). Older patients had more comorbidities (atrial fibrillation, history of cardiac decompensation, systemic hypertension, pulmonary hypertension, and chronic kidney disease) and they presented more postoperative complications (50.0% vs 33.7%; P = 0.043), with a longer hospital stay (8.9 ± 6.9 vs 6.6 ± 4.6 days; P = 0.005). To assess the burden of age, a propensity score was awarded to postoperative complications. Active smoking, chronic pulmonary disease, chronic kidney disease, associated ischemic heart disease, obesity, and cardio pulmonary by-pass duration were described as independent risk factors. When matched on this propensity score, there was no difference in morbidity or mortality between group 1 and group 2.Older patients suffered more postoperative complications, which were related to their comorbidities and not only to their age.

Coronary bifurcation lesions treated with simple or complex stenting: 5-year survival from patient-level pooled analysis of the Nordic Bifurcation Study and the British Bifurcation Coronary Study

AIMS

Randomized trials of coronary bifurcation stenting have shown better outcomes from a simple (provisional) strategy rather than a complex (planned two-stent) strategy in terms of short-term efficacy and safety. Here, we report the 5-year all-cause mortality based on pooled patient-level data from two large bifurcation coronary stenting trials with similar methodology: the Nordic Bifurcation Study (NORDIC I) and the British Bifurcation Coronary Study: old, new, and evolving strategies (BBC ONE).

METHODS AND RESULTS

Both multicentre randomized trials compared simple (provisional T-stenting) vs. complex (culotte, crush, and T-stenting) techniques, using drug-eluting stents. We analysed all-cause death at 5 years. Data were collected from phone follow-up, hospital records, and national mortality tracking. Follow-up was complete for 890 out of 913 patients (97%). Both Simple and Complex groups were similar in terms of patient and lesion characteristics. Five-year mortality was lower among patients who underwent a simple strategy rather than a complex strategy [17 patients (3.8%) vs. 31 patients (7.0%); P = 0.04].

CONCLUSION

For coronary bifurcation lesions, a provisional single-stent approach appears to be associated with lower long-term mortality than a systematic dual stenting technique.

Serial Morphological Changes of Side-Branch Ostium after Paclitaxel-Coated Balloon Treatment of De Novo Coronary Lesions of Main Vessels

PURPOSE

The effects on the side-branch (SB) ostium, following paclitaxel-coated balloon (PCB) treatment of de novo coronary lesions of main vessels have not been previously investigated. This study was aimed at evaluating the serial morphological changes of the SB ostium after PCB treatment of de novo coronary lesions of main vessels using optical coherence tomography (OCT).

MATERIALS AND METHODS

This prospective, single-center observational study enrolled patients with de novo lesions, which were traversed by at least one SB (≥1.5 mm) and were treated with PCB. The SB ostium was evaluated with serial angiographic and OCT assessments pre- and post-procedure, and at 9-months follow-up.

RESULTS

Sixteen main vessel lesions were successfully treated with PCB, and 26 SBs were included for analysis. Mean SB ostial lumen area increased at 9-months follow-up (0.92±0.68 mm² pre-procedure, 1.03±0.77 mm² post-procedure and 1.42±1.18 mm² at 9-months). The SB ostial lumen area gain was 0.02±0.24 mm² between pre- and post-procedure, 0.37±0.64 mm² between post-procedure and 9-months, and 0.60±0.93 mm² between pre-procedure and 9-months. The ostial lumen area increased by 3.9% [interquartile range (IQR) of -33.3 to 10.4%] between pre- and post-procedure, 52.1% (IQR of -0.7 to 77.3%) between post-procedure and 9-months and 76.1% (IQR of 18.2 to 86.6%) between pre-procedure and 9-months.

CONCLUSION

PCB treatment of de novo coronary lesions of main vessels resulted in an increase in the SB ostial lumen area at 9-months.

Safety of hydrophilic guidewires used for side-branch protection during stenting and proximal optimization technique in coronary bifurcation lesions

BACKGROUND AND PROPOSE

In coronary bifurcation lesions (CBL), hydrophilic guidewires used for side-branch (SB) protection can be withdrawn from underneath the stent easier than other wires. However, the safety of which has not been investigated.

METHODS/MATERIALS

We performed scanning electron microscopic (SEM) examination of hydrophilic wires - the Whisper and Runthrough wires - used for SB protection during stenting and proximal optimization technique (POT) in 30 patients with CBL. The distal 15cm of the wire was examined every 1mm by SEM and 4500 segments were analyzed to investigate for wire fracture, polymer shearing (PS), and its correlations with post-stenting creatine kinase (CK)-MB release.

RESULTS

SEM examination showed no evidence for wire fracture. The total area of PS and the largest defect on the wire were significantly larger with the Whisper wire versus the Runthrough wire (0.15±0.04mm² vs. 0.026±0.01mm² and 0.04±0.05mm² vs. 0.01±0.01mm²; P<0.05, respectively). The total length of PS and the longest defect on the wire were significantly longer with the Whisper wire vs. the Runthrough wire (12.1±14.5mm vs. 2.7±3.0mm and 2.9±4.2mm vs. 1.0±1.2mm; P<0.05, respectively), but there were weak correlations between the extents of PS with CK-MB release.

CONCLUSIONS

Hydrophilic guidewires may be safely used for SB protection during stenting and POT in CBLs. The extent of PS was significantly greater with the Whisper wire than with the Runthrough wire, but its correlation with post-stenting CK-MB release was weak.

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.

Clinical and angiographic predictors of major side branch occlusion after main vessel stenting in coronary bifurcation lesions

Background:

Major side branch (SB) occlusion is one of the most serious complications during percutaneous coronary intervention (PCI) for bifurcation lesions. We aimed to characterize the incidence and predictors of major SB occlusion during coronary bifurcation intervention.

Methods:

We selected consecutive patients undergoing PCI (using one stent or provisional two stent strategy) for bifurcation lesions with major SB. All clinical characteristics, coronary angiography findings, PCI procedural factors and quantitative coronary angiographic analysis data were collected. Multivariate logistic regression analysis was performed to identify independent predictors of SB occlusion. SB occlusion after main vessel (MV) stenting was defined as no blood flow or any thrombolysis in myocardial infarction (TIMI) flow grade decrease in SB after MV stenting.

Results:

Among all 652 bifurcation lesions, 32 (4.91%) SBs occluded. No blood flow occurred in 18 lesions and TIMI flow grade decreasing occurred in 14 lesions. In multivariate analysis, diameter ratio between MV/SB (odds ratio [OR]: 7.71, 95% confidence interval [CI]: 1.53–38.85, P = 0.01), bifurcation angle (OR: 1.03, 95% CI: 1.02–1.05, P < 0.01), diameter stenosis of SB before MV stenting (OR: 1.05, 95% CI: 1.03–1.07, P < 0.01), TIMI flow grade of SB before MV stenting (OR: 3.59, 95% CI: 1.48–8.72, P < 0.01) and left ventricular eject fraction (LVEF) (OR: 1.06, 95% CI: 1.02–1.11, P < 0.01) were independent predictors of SB occlusion.

Conclusions:

Among clinical and angiographic findings, diameter ratio between MV/SB, bifurcation angle, diameter stenosis of SB before MV stenting, TIMI flow grade of SB before MV stenting and LVEF were predictive of major SB occlusion after MV stenting.

Reduction in incomplete stent apposition area caused by jailed struts after single stenting at left main bifurcation lesions: micro-CT analysis using a three-dimensional elastic bifurcated coronary artery model

Stent struts protruding into ostial side branch called “jailed strut” at bifurcation lesions is a likely cause of thrombus formation. We aimed to investigate the influences of multiple kissing balloon inflation (KBI) for stent expansion, and stent platform design, respectively, on the reduction of incomplete stent apposition area (ISA area) caused by jailed struts at a side-branch ostium, using a three-dimensional elastic left main (LM) bifurcated coronary artery model. The referenced LM bifurcation angle data of 209 patients were stratified by tertiles focusing on the angle between the LM trunk (LMT) and left anterior descending artery (LAD). A bifurcation model was fabricated with angles of 129°, 122.2°, and 76.4° for LMT–LAD, LMT–left circumflex (LCx), and LAD–LCx, respectively, and with diameters of 5, 3.75, and 3.5 mm for LMT, LAD, and LCx, respectively; these diameters fulfill Murray’s law. A 75 % stenosis was included along the LMT. One-time and three-time KBIs were conducted using two-link Nobori and three-link Xience Xpedition (n = 6 each). The ISA area was quantified using micro-CT. Three-time KBI was effective in reducing the ISA area compared with one-time KBI for both the Nobori (p = 0.05) and Xience Xpedition (p = 0.07). The ISA area was smaller in the Nobori than in the Xience Xpedition, both in one-time and three-time KBI (one-time KBI: p = 0.003; three-time KBI: p = 0.001). Our findings of this study on reducing the ISA area by focusing on an interventional technique and stent design may help to improve coronary bifurcation intervention for a possibly better long-term clinical outcome.

A Novel Tram Stent Method in the Treatment of Coronary Bifurcation Lesions - Finite Element Study

A novel stent was designed for the treatment of coronary bifurcation lesion, and it was investigated for its performance by finite element analysis. This study was performed in search of a novel method of treatment of bifurcation lesion with provisional stenting. A bifurcation model was created with the proximal vessel of 3.2 mm diameter, and the distal vessel after the side branch (2.3 mm) was 2.7 mm. A novel stent was designed with connection links that had a profile of a tram. Laser cutting and shape setting of the stent was performed, and thereafter it was crimped and deployed over a balloon. The contact pressure, stresses on the arterial wall, stresses on the stent, the maximal principal log strain of the main artery and the side-branch were studied. The study was performed in Abaqus, Simulia. The stresses on the main branch and the distal branch were minimally increased after deployment of this novel stent. The side branch was preserved, and the stresses on the side branch were lesser; and at the confluence of bifurcation on either side of the side branch origin the von-Mises stress was marginally increased. The stresses and strain at the bifurcation were significantly lesser than the stresses and strain of the currently existing techniques used in the treatment of bifurcation lesions though the study was primarily focused only on the utility of the new technology. There is a potential for a novel Tram-stent method in the treatment of coronary bifurcation lesions.

Dedicated bifurcation stents - Mechanistic, hardware, and technical aspects

Percutaneous coronary intervention (PCI) in bifurcation lesions is associated with lower success rate, higher acute complication rates and higher event rates in follow-up.

The reason for this higher than usual complication rate relates to the relationship between anatomy, flow, and atheroma distribution in bifurcation lesions.

Further, stenting these lesions can be a prolonged procedure and can be technically more demanding. The most common complication is the loss of significant side branch (SB). Main vessel (MV) stenting may enhance the carina displacement and atheroma shift across the SB ostium leading to SB ostium narrowing.

Finally, complications, if they occur, are more difficult to manage. Dedicated bifurcation stent has been developed to overcome the number of limitations associated with conventional bifurcation PCI. The main advantage of most dedicated bifurcation stents is to allow the operator to perform the procedure on a bifurcation lesion without the need to rewire the SB.

Impact of final kissing balloon inflation on vessel healing following drug-eluting stent implantation: Insight from the optical coherence tomography sub-study of the J-REVERSE trial

BACKGROUND

We sought to clarify the impact of final kissing inflation (FKI) after single stenting of bifurcation lesions on vessel healing.

METHODS

From the J-REVERSE registry enrolling 303 bifurcation lesions treated with provisional single stenting using sirolimus- (SES) or everolimus-eluting stent (EES), 65 lesions treated with (n=30) and without (n=35) FKI underwent 9-month follow-up optical coherence tomography. Average stent eccentricity index (SEI: minimum/maximum stent diameter) and neointimal unevenness score (NUS: maximum/average neointimal thickness of the same cross-section) for the proximal, bifurcation, and distal segments were compared between FKI and non-FKI groups.

RESULTS

At the proximal segment, the FKI group demonstrated significantly larger average stent area with greater asymmetric stent expansion, and average lumen area remained significantly larger at 9-month follow-up despite a tendency toward greater neointimal proliferation. Jailed strut and thrombus incidence were also significantly lower at the side branch orifice, and NUS was significantly smaller at the bifurcation and proximal segments in the FKI group.

CONCLUSIONS

Nine months after SES and EES treatment of bifurcation lesions, FKI reduced proximal-segment luminal narrowing. Considering its homogeneous neointimal distribution and fewer jailed struts, FKI may be beneficial for treating bifurcation lesions.

Mechanism of Residual Lumen Stenosis at the Side Branch Ostium After Final Kissing Balloon Inflation: A Volumetric Intracoronary Ultrasound Study of Coronary Bifurcation Lesions

OBJECTIVES

To investigate the mechanisms of residual stenosis (RS) at side branch ostium (SBO) after final kissing balloon inflation (FKI) and clarify the impact of carina- and plaque-shifts on RS.

BACKGROUND

Carina- and plaque-shift induce SBO compromise. FKI is an effective technique to treat this complication; however, RS often persist, and are associated with restenosis at SBO.

METHODS

We performed serial volumetric analysis of 91 bifurcations in which crossover-stenting with FKI and pre-/post-intravascular ultrasounds (IVUS) were completed in both branches. The plaque- and carina-shifts were defined as an increase in the plaque-volume and a decrease in the vessel-volume at the SBO, respectively. RS at the SBO, defined as area stenosis >50% on IVUS, was identified in 19 lesions.

RESULTS

After FKI, the plaque volume- significantly increased at the SBO, with its reduction in the proximal main vessel (MV). However, at the SBO, the volumetric lumen change correlated with vessel change (ρ = 0.690, P < 0.001), but not plaque change (P = 0.390), suggesting that RS at SBO was more likely associated with inadequate vessel stretch, not plaque increase after FKI. Carina-shift was more frequently found in cases with RS, compared to those without RS (37% vs. 11%, P = 0.013). Pre-procedure IVUS findings to predict RS at SBO after FKI were negative-remodeling at distal MV, plaque -burden at distal MV, and plaque-burden at the SBO.

CONCLUSIONS

Carina-shift has a greater contribution to the formation of RS at SBO after FKI. The pre-procedure IVUS provides helpful information for predicting the RS after FKI.

Randomized Comparisons Between Different Stenting Approaches for Bifurcation Coronary Lesions With or Without Side Branch Stenosis

OBJECTIVES

This study sought to evaluate the optimal percutaneous coronary intervention techniques using drug-eluting stents for bifurcation coronary lesions.

BACKGROUND

The optimal bifurcation stenting technique needs to be evaluated.

METHODS

The trial included 2 randomization studies separated by the presence of side branch (SB) stenosis for patients having non-left main bifurcation lesions. For 306 patients without SB stenosis, the routine final kissing balloon or leave-alone approaches were compared. Another randomization study compared the crush or single-stent approaches for 419 patients with SB stenosis.

RESULTS

Between the routine final kissing balloon and leave-alone groups for nondiseased SB lesions, angiographic restenosis occurred in 17.9% versus 9.3% (p=0.064), comprising 15.1% versus 3.7% for the main branch (p=0.004) and 2.8% versus 5.6% for the SB (p=0.50) from 214 patients (69.9%) receiving 8-month angiographic follow-up. Incidence of major adverse cardiac events including death, myocardial infarction, or target vessel revascularization over 1 year was 14.0% versus 11.6% between the routine final kissing balloon and leave-alone groups (p=0.57). In another randomization study for diseased SB lesions, 28.2% in the single-stent group received SB stents. From 300 patients (71.6%) receiving angiographic follow-up, between the crush and single-stent groups, angiographic restenosis rate was 8.4% versus 11.0% (p=0.44), comprising 5.2% versus 4.8% for the main branch (p=0.90) and 3.9% versus 8.3% for the SB (p=0.12). One-year major adverse cardiac events rate between the crush and single-stent groups was 17.9% versus 18.5% (p=0.84).

CONCLUSIONS

Angiographic and clinical outcomes were excellent after percutaneous coronary intervention using drug-eluting stents with any stent technique for non-left main bifurcation lesions once the procedure was performed successfully.

Therapeutic effect of interventional therapy for unprotected left main coronary artery lesions in aged patients

Objective

To assesse the therapeutic effect of interventional therapy in aged patients with unprotected left main coronary artery (UPLM) lesions.

Methods

A total of 61 patients who were over 60 years and accepted interventional therapy of UPLM from January 2012 to November 2013 in our hospital were followed up for average 14.6 months by telephone call or outpatient visits. We analyzed the clinical features data of the interventional therapy and assessed the factors that likely influenced the clinical prognosis.

Results

The average age of the 61 patients was 73.9 years. The average left ventricular ejection fraction (LVEF) was 47.7%. The median of the estimated glomerular filtration rate (eGFR) was 52 mL/min per 1.73 mm². The average SYNTAX score was 27.4 and the median of stent length was 36 mm. The cumulative incidence of cardiac death at 30 days and major adverse cardiac events (MACE) after one year was 6.6% and 32.5% estimated by Kaplan-Meier plots respectively. No severe hemorrhagic complications were observed during follow-up period. On multivariate regression analysis with a COX proportional hazards model, LVEF was an independent predictor of cardiac death at 30 days [Hazard ratio (HR): 0.7, P = 0.01]. As for MACE after one year, LVEF and eGFR were both independent predictors (HR: 0.91, P = 0.06 for LVEF, HR: 0.03, P = 0.097 for eGFR).

Conclusions

The interventional therapy for UPLM was effective and safe in aged patients. LVEF was the only predictor of cardiac death at 30 days, while LVEF and eGFR were both independent predictors of MACE after one year.

The impact of three-dimensional optical coherence tomography and kissing-balloon inflation for stent implantation to bifurcation lesions

The rates of restenosis and stent thrombosis after the therapeutic stent deployment for bifurcation lesions are still comparably high after the introduction of the new-generation drug-eluting stents (DESs), because of the various factors including their morphology. We experienced a case of a successful percutaneous coronary intervention using three-dimensional optical coherence tomography (3D OCT) with a single stent deployment to a bifurcation lesion of the left anterior descending artery (LAD) and left circumflex artery (LCx) with a following kissing-balloon inflation (KBI). The 3D OCT, after the inflation of the jailed ostium of the LCx following the stent deployment to the LAD crossing the LCx, could clearly demonstrate a stent deformation and incomplete apposition at an opposite site of the LCx, which may cause high rates of restenosis and stent thrombosis. These stent abnormalities were steadily corrected by a subsequent KBI of the LAD and LCx. Furthermore, the 3D OCT images were the same findings as those of the experiments from both an in vitro phantom coronary bifurcation model and macroscopic images of the stent. <Learning objective: In view of this case report, these modalities with three-dimensional optical coherence tomography and the techniques for the following kissing-balloon inflation may be one of the useful and effective therapeutic strategies to reduce the rates of restenosis and stent thrombosis of the percutaneous coronary intervention for bifurcation lesions.>.