The story of plaque shift and carina shift

Carina: A major determinant in the pathophysiology and treatment of coronary bifurcation lesions

Over the last decade, several in vivo and computational investigations have significantly advanced our understanding of the pathophysiology of coronary bifurcations, contributing to the enhancement of their percutaneous revascularization. The carina of the coronary bifurcations plays a substantial role in generating their main hemodynamic features, including distinctive flow patterns with secondary flows and specific shear stress patterns. These factors play a pivotal role in determining the susceptibility, development, and progression of atherosclerosis. The underlying pathophysiological mechanisms of atherosclerosis in coronary bifurcations are complex and multifactorial. Understanding these mechanisms is fundamental to comprehending lesions at the bifurcation level and informing future treatment strategies. This review aims to present the currently available data regarding the pathophysiological and prognostic role of the carina in coronary bifurcations, offering an interpretation of these findings from the perspective of interventional cardiologists, providing valuable insights for their clinical practice.

Risk Assessment of Side Branch Compromise After Coronary Bifurcation Stenting - A Substudy of the 3D-OCT Bifurcation Registry

BACKGROUND

Side branch (SB) occlusion during bifurcation stenting is a serious complication. This study aimed to predict SB compromise (SBC) using optical coherence tomography (OCT).

METHODS AND RESULTS

Among the 168 patients who enrolled in the 3D-OCT Bifurcation Registry, 111 bifurcation lesions were analyzed to develop an OCT risk score for predicting SBC. SBC was defined as worsening of angiographic SB ostial stenosis (≥90%) immediately after stenting. On the basis of OCT before stenting, geometric parameters (SB diameter [SBd], length from proximal branching point to carina tip [BP-CT length], and distance of the polygon of confluence [dPOC]) and 3-dimensional bifurcation types (parallel or perpendicular) were evaluated. SBC occurred in 36 (32%) lesions. The parallel-type bifurcation was significantly more frequent in lesions with SBC. The receiver operating characteristic curve indicated SBd ≤1.77 mm (area under the curve [AUC]=0.73, sensitivity 64%, specificity 75%), BP-CT length ≤1.8 mm (AUC=0.83, sensitivity 86%, specificity 68%), and dPOC ≤3.96 mm (AUC=0.68, sensitivity 63%, specificity 69%) as the best cut-off values for predicting SBC. To create the OCT risk score, we assigned 1 point to each of these factors. As the score increased, the frequency of SBC increased significantly (Score 0, 0%; Score 1, 8.7%; Score 2, 28%; Score 3, 58%; Score 4, 85%; P<0.0001).

CONCLUSIONS

Prediction of SBC using OCT is feasible with high probability.

Comparison of the Incidence of Periprocedural Myocardial Infarction in Bifurcation Lesions Between Medina (1,1,1) and (0,1,1) in Elective Percutaneous Coronary Intervention

Periprocedural myocardial infarction (PMI) following percutaneous coronary intervention (PCI) is more frequently observed in true bifurcation lesions such as Medina (1,1,1) and (0,1,1). The aim of this study is to compare the incidence of PMI in elective PCI between Medina (1,1,1) and (0,1,1) bifurcation lesions. This was a retrospective, single-center study. We included 162 true bifurcation lesions, which were divided into the (1,1,1) group (n = 85) and the (0,1,1) group (n = 77). We compared the incidence of PMI between the two groups and performed multivariate logistic regression analysis using PMI as a dependent variable. The incidence of PMI was similar in the (1,1,1) group and the (0,1,1) group (12.9% versus 15.6%, P = 0.658). The final TIMI flow grade of the side branches and that of the main branches were also similar in the two groups. In multivariate logistic regression analysis, Medina classification (1,1,1) was not associated with PMI (odds ratio (OR), 0.996; 95% confidence interval (CI), 0.379-2.621; P = 0.994), but the angle of the side branch < 45° (OR, 3.569; 95% CI, 1.320-9.654; P = 0.012), lesion length in a main vessel (per 10-mm increase) (OR, 1.508; 95% CI, 1.104-2.060; P = 0.010), and absence of side branch protection (OR, 3.034; 95% CI, 1.095-8.409; P = 0.033) were significantly associated with PMI. In conclusion, the Medina (1,1,1) bifurcation lesions did not increase the incidence of PMI as compared to Medina (0,1,1). However, the narrow side branch angle, diffuse long lesion, and absence of side branch protection were significantly associated with PMI. We should pay attention to these high-risk features in the treatment of true bifurcation lesions.

Effect of Wire Jailing at Side Branch in 1-Stent Strategy for Coronary Bifurcation Lesions

OBJECTIVES

This study aimed to determine whether side branch (SB) wire jailing before main vessel (MV) stenting could prevent SB occlusion after the 1-stent strategy for bifurcation percutaneous coronary intervention.

BACKGROUND

The benefits of SB wire jailing in the 1-stent strategy remain unclear.

METHODS

From the COBIS (Coronary Bifurcation Stenting) III registry, 1,890 patients with bifurcation lesions who underwent the 1-stent strategy using second-generation drug-eluting stents were identified and classified into 2 groups according to the use of SB wire jailing: wire jailing (n = 819) and non-wire jailing (n = 1,071). The incidence of SB occlusion (Thrombolysis In Myocardial Infarction flow grade <3) and target lesion failure (cardiac death, myocardial infarction, or target lesion revascularization) was compared.

RESULTS

The incidence of final SB occlusion was not significantly different between wire jailing (1.8%) vs non-wire jailing (2.9%; P = 0.182). However, wire jailing at the SB was a significant protective factor for SB occlusion after MV stenting on multivariate analysis and was significantly associated with a lower incidence of SB occlusion in patients with significant stenoses (≥60%) at the SB (5.1% vs 11.3%; odds ratio: 0.42; 95% CI: 0.19-0.89; P = 0.028) or MV (3.1% vs 6.2%; odds ratio: 0.49; 95% CI: 0.24-0.95; P = 0.039). During follow-up (median 52 months), the incidence of target lesion failure was not significantly different between wire jailing and non-wire jailing (7.6% vs 6.3%; P = 0.343).

CONCLUSIONS

During bifurcation percutaneous coronary intervention with the 1-stent strategy, wire jailing at the SB was associated with a lower rate of final SB occlusion following MV stenting in patients with severe stenoses at the SB or MV but not with overall bifurcation lesions. Long-term clinical outcomes were comparable between the 2 groups.

Inflation Pressure in Side Branch during Modified Jailed Balloon Technique Does Not Affect Side Branch Outcomes

Objectives

This study aimed to investigate the optimal jailed balloon inflation in the side branch during the modified jailed balloon technique for bifurcated lesions.

Background

The modified jailed balloon technique is one of the effective techniques to minimize the emergence of side branch (SB) compromise by preventing plaque or carina shifting during a single stent strategy in the main vessel with provisional SB treatment. However, there are no detailed studies on the method of optimal jailed balloon inflation.

Methods

We analyzed 51 consecutive patients who underwent percutaneous coronary intervention (PCI) for bifurcated lesions with a modified jailed balloon technique between September 2018 and December 2020. These 51 patients were divided into two groups according to the magnitude of inflation pressure of the jailed balloon: a higher pressure (HP) group and lower pressure (LP) group.

Results

No significant differences in procedural outcomes were observed between the two groups. The findings of SB compromise were relatively common with our procedure (30.0% in the HP group; 33.3% in the LP group). The patterns of SB compromise such as dissection or stenosis increase were observed at similar frequencies between them. In particular, SB dissection was noted in the SB lesion with some plaque burden, irrespective of the magnitude of the jailed balloon inflation pressure. Univariate analysis showed that calcification in the main vessel and SB lesion length was significantly associated with SB compromise. Finally, all PCI procedures were successfully completed without any provisional stent deployment in SB.

Conclusions

We speculate that lesion characteristics rather than the PCI procedural factors may be critical determinants to cause SB compromise.

Noncalcified plaque burden quantified from coronary computed tomography angiography improves prediction of side branch occlusion after main vessel stenting in bifurcation lesions: results from the CT-PRECISION registry

OBJECTIVES

To assess the incremental value of quantitative plaque features measured from computed tomography angiography (CTA) for predicting side branch (SB) occlusion in coronary bifurcation intervention.

METHODS

We included 340 patients with 377 bifurcation lesions in the post hoc analysis of the CT-PRECISION registry. Each bifurcation was divided into three segments: the proximal main vessel (MV), the distal MV, and the SB. Segments with evidence of coronary plaque were analyzed using semi-automated software allowing for quantitative analysis of coronary plaque morphology and stenosis. Coronary plaque measurements included calcified and noncalcified plaque volumes, and corresponding burdens (respective plaque volumes × 100%/vessel volume), remodeling index, and stenosis.

RESULTS

SB occlusion occurred in 28 of 377 bifurcation lesions (7.5%). The presence of visually identified plaque in the SB segment, but not in the proximal and distal MV segments, was the only qualitative parameter that predicted SB occlusion with an area under the curve (AUC) of 0.792. Among quantitative plaque parameters calculated for the SB segment, the addition of noncalcified plaque burden (AUC 0.840, p = 0.003) and low-density plaque burden (AUC 0.836, p = 0.012) yielded significant improvements in predicting SB occlusion. Using receiver operating characteristic curve analysis, optimal cut-offs for noncalcified plaque burden and low-density plaque burden were > 33.6% (86% sensitivity and 78% specificity) and > 0.9% (89% sensitivity and 73% specificity), respectively.

CONCLUSIONS

CTA-derived noncalcified plaque burden, when added to the visually identified SB plaque, significantly improves the prediction of SB occlusion in coronary bifurcation intervention.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03709836 registered on October 17, 2018.

Rescue treatment and follow-up intervention of a left main acute myocardial infarction with typical carina shift under 3D optical coherence tomography: A case report

BACKGROUND

Coronary intervention for bifurcation lesions is still challenging for interventional cardiologists. Left main (LM) bifurcation lesions have a higher risk due to the vast blood supply in this area and treatment choice is difficult. Ostial compromise of the side branch decreases patient prognosis, and its management is still an issue despite the different strategies and devices available.

CASE SUMMARY

A 42-year-old male patient was admitted to hospital due to chest pain and syncope. Coronary angiography showed acute LM occlusion. Following thrombus aspiration, a LM bifurcation lesion remained. Coronary angiography was repeated one week later, and at the same time, 3D optical coherence tomography (OCT) was carried out to better show the geometry of the bifurcation, which confirmed that the stenosis in the ostial left circumflex artery was caused by a long carina. After assessment of the plaque characteristics and the minimum lumen area, the cross-over strategy, kissing balloon inflation and proximal optimization technique were chosen to treat the bifurcation lesion. A “moving” carina was found twice during the intervention. Good stent apposition and expansion were confirmed by OCT after proximal optimization technique. The three-month follow-up showed good recovery and normal cardiac function.

CONCLUSION

3D-OCT can facilitate decision-making for coronary interventions in patients with critical bifurcation lesions.

Relationship between neointimal strut bridge and jailed side-branch ostial area

BACKGROUND

Our study analyzed the relationship between the neointimal strut bridge and jailed side-branch (SB) ostial area in patients with coronary heart disease (CHD) who had a single drug-eluting stent (DES) crossover of the left anterior descending coronary artery (LAD)/diagonal branch (D) bifurcation.

PATIENTS AND METHODS

A total of 64 CHD patients with an LAD/D bifurcation treated by optical coherence tomography (OCT)-guided single-DES implantation and followed up at 1 year after primary percutaneous intervention (pPCI) were enrolled in our study. According to the two-dimensional OCT results, patients were divided into a non-neointimal bridge group (n = 44) and a neointimal bridge group (n = 20). Basic clinical, angiographic, 2D and 3D OCT, and DES results were analyzed.

RESULTS

The blood lipid levels of the two groups after the 1‑year follow-up were lower than the levels 1 year earlier (p < 0.05). There was a notable decrease in the SB ostial minimum lumen diameter and area directly after pPCI vs. before pPCI in both groups. The diameter stenosis directly after pPCI showed a clear increase compared with the pre-pPCI value in both groups (p < 0.05 or p < 0.01, respectively). The strut distance of the neointimal bridges in the neointimal bridge group was greater than in the non-neointimal bridge group (p < 0.05). A clearly short strut distance of the neointimal bridge was observed compared with the strut distance of the non-neointimal bridge in the neointimal bridge group (p < 0.05). A larger neointimal bridge area and a smaller SB ostial area were found in the neointimal bridge group compared with the non-neointimal bridge group (p < 0.05 or p < 0.01, respectively).

CONCLUSION

A short strut distance facilitated formation of a neointimal bridge, which significantly influenced the SB ostial area after single crossover stenting of the SB orifice at the 1‑year follow-up.

Double kissing mini-culotte versus mini-culotte stenting: insights from micro-computed tomographic imaging of bench testing

AIMS

This study aimed to evaluate the morphologic characteristics of double kissing (DK) mini-culotte and mini-culotte stenting through imaging of bench testing.

METHODS AND RESULTS

DK mini-culotte and mini-culotte stenting were performed in two silicone bifurcated phantoms with branch vessel diameter differences of 0.5 mm (Model 1) and 1.25 mm (Model 2), and their morphologic characteristics were evaluated by micro-computed tomography. In Model 1, metal carina length (0.25±0.13 mm vs 0.55±0.15 mm), area stenosis of the side branch ostium (SBO) (4.65±3.24% vs 12.5±3.93%), and maximum distance of malapposed struts for the wall facing the SBO (0.27±0.08 mm vs 0.49±0.15 mm) were lower in the DK mini-culotte group than in the mini-culotte group. In Model 2, metal carina length (0.21±0.47 mm vs 0.47±0.12 mm), SBO area stenosis (5.13±3.37% vs 15.00±6.18%), and maximum distance of malapposed struts (0.32±0.13 mm vs 0.68±0.10 mm) were also lower in the DK mini-culotte group. The results of factorial analysis showed that maximum distance of malapposed struts tended to be shorter in Model 1 (F=4.226, p=0.062).

CONCLUSIONS

Compared with mini-culotte stenting, DK mini-culotte stenting was associated with shorter metal carina length, shorter maximum distance of malapposed struts, and smaller SBO area stenosis. Thus, DK mini-culotte stenting may obtain better morphologic characteristics.

Carina Bifurcation Angle and Side Branch Occlusion in Coronary Bifurcation Lesions Intervention: Angiographic Lesions Characteristic Role in Determining Its Relation

Side branch occlusion has been implicated as a complication after percutaneous coronary intervention in coronary bifurcation lesions. The role of carina bifurcation angle as one of the characteristics of the coronary bifurcation lesions in causing side branch occlusion after percutaneous coronary intervention is still debated. This study aims to assess the correlation between carina bifurcation angles as one of the characteristics of the coronary bifurcation lesions and side branch occlusion in elective percutaneous coronary intervention. This is a cross-sectional study which utilizes CAAS 5.1 software to measure carina bifurcation angle. We collected 113 lesions in 108 patients that met the inclusion criteria from January 2016 to October 2016. Side branch occlusion occurred in 15 lesions (13.3%), with median carina bifurcation angle 19.17 degrees ( p  < 0.001). Multivariate analysis showed there is a correlation between carina bifurcation angle with side branch occlusion, OR (odds ratio) 0.86 (95% CI [confidence interval]: 0.80-0.92) with ≤ 33.71 degrees cut off value. Increased risk of side branch occlusion was found in small carina bifurcation angle.

Plaque morphology predictors of side branch occlusion after provisional stenting in coronary bifurcation lesion: Results of optical coherence tomography bifurcation study (ORBID)

OBJECTIVES

The aim of this study was to identify the predictors of side branch (SB) ostial stenosis developed after provisional stenting of the main vessel (MV) using optical coherence tomography (OCT).

BACKGROUND

Provisional stenting remains the main approach to treatment of bifurcation lesions; however, it may result in the narrowing of SB ostium. There is little information about underlying plaque morphology of the MV lesion and its potential impact on the SB after provisional stenting.

METHODS

Patients with stable coronary disease with angiographic MV lesion not involving SB were included in a prospective single center study. The primary outcome was significant SB ostium stenosis (SBOS), defined as residual stenosis of >50% after MV stenting.

RESULTS

Thirty bifurcation lesions in 30 patients were analyzed in the study. Poststenting significant SBOS was observed in 30% of patients. The MV lesions with SBOS > 50% were characterized by a higher prevalence of lipid rich plaques (100 vs. 64%, p = 0.040) and spotty calcifications (60 vs. 0%, p = 0.005). Maximal lipid arcs were greater (257° vs. 132°, p = 0.001) and lipid volume index was higher (1380 vs. 574, p = 0.012) in the SBOS >50% group. Multivariate logistic regression analysis identified maximal lipid arc (odds ratio (OR): 1.014, p = 0.038) and the presence of lipid plaque contralateral to SB ostium (OR: 8.14, p = 0.046) before stenting as independent predictors of significant SBOS after PCI.

CONCLUSIONS

High lipid content of the MV lesion and a contralateral location of lipid in the bifurcation area may contribute to SBOS after provisional stenting. © 2016 Wiley Periodicals, Inc.