Dominant contribution of negative remodeling to development of significant coronary bifurcation narrowing

Current Challenges in Coronary Bifurcation Interventions

Coronary bifurcation lesions account for a significant proportion of all percutaneous coronary interventions (PCIs). Interventional treatment of coronary bifurcations is related to significant technical challenges, high complication rates, and worse angiographic and long-term clinical outcomes. This review covers the specific features and structure of coronary bifurcation and explores the main challenges in the interventional treatment of these lesions. This review evaluates various methodologies designed to address these lesions, considering factors such as plaque distribution and bifurcation geometry. It also emphasizes the limitations associated with current techniques. A novel combined optimization approach applied in the interventional treatment of coronary bifurcation may offer superior procedural and long-term outcomes. This combined technique could potentially address the drawbacks of each method, providing a more effective solution for optimizing stent placement in bifurcation lesions. Refining and evaluating these combined techniques is essential for improving clinical outcomes in patients with bifurcation lesions.

Intravascular ultrasound guidance in the evaluation and treatment of left main coronary artery disease

Percutaneous coronary intervention (PCI) of left main coronary artery (LMCA) disease has become an acceptable revascularization strategy. Evaluating the extent and characteristics of obstructive disease of the LMCA by angiography is challenging and limited in its accuracy. In contrast, intravascular ultrasound (IVUS) provides accurate imaging of the coronary lumen as well as quantitative measurements and quantitative assessment of the vessel wall components. IVUS for LMCA PCI should be performed before, during, and after intervention; IVUS enhances every step in the procedure and is associated with a mortality advantage in comparison with angiographic guidance alone. In this review, we provide an update on LMCA PCI and the role of IVUS for lesion assessment and stent optimization. In addition, the latest clinical evidence of the benefits of IVUS-guided LMCA PCI as compared to angiography is reviewed.

Intravascular ultrasound in the evaluation and treatment of left main coronary artery disease: a consensus statement from the European Bifurcation Club

Interventional cardiology and coronary stent insertion have an increasing role in the optimal management of left main coronary artery (LMCA) stenosis. Assessing the extent of obstructive disease of the LMCA by angiography alone can be challenging. However, in contrast to the two-dimensional, shadow graphic nature of coronary angiography, intravascular ultrasound (IVUS) is an accurate tomographic technique for assessing both the coronary lumen and the vessel wall characteristics. Consequently, it is a particularly useful technique in imaging the LMCA before, during and after intervention. The European Bifurcation Club (EBC) recommends the use of IVUS during most LMCA interventions. The purpose of this consensus document is to review the available IVUS data on LMCA disease evaluation and treatment. It is a practical guide to show "how and when" to use the imaging modality. It is hoped that a standardisation of the practical approach to imaging may allow consolidation of learning and, ultimately, improve patient outcomes.

Mechanism of luminal patency of the self-expanding Sideguard sidebranch stent: evaluation by intravascular ultrasound and optical coherence tomography

BACKGROUND

The Cappella Sideguard (CS) sidebranch stent is a self-expanding, thin-strut, nitinol device with anatomic flaring at the sidebranch ostium designed to treat bifurcation lesions.

OBJECTIVE

To evaluate the mechanism of long-term lumen patency of the novel, self-expanding CS sidebranch stent compared with a balloon-expandable stent in the main vessel.

METHODS

We performed intravascular ultrasound postintervention and at follow-up in 24 CS stents and in 28 balloon-expandable drug-eluting stents deployed in the corresponding main vessel. Thirteen patients also had optical coherence tomography (OCT) at follow-up to evaluate neointimal hyperplasia and strut coverage.

RESULTS

CS stent area at the sidebranch carina increased significantly from 3.8 ± 1.2 mm(2) postintervention to 4.6 ± 1.2 mm(2) at follow-up (P < 0.001), resulting in no change in lumen area (3.8 ± 1.2 mm(2) to 3.7 ± 1.2 mm(2) , P = 0.72) despite a neointimal area at follow-up of 0.9 ± 0.8 mm(2) . Volumetric changes were similar, and the distribution of neointimal hyperplasia peaked 1-2 mm distal to the carina. Change of lumen volume inversely correlated to the neointimal volume (R = -0.48, P < 0.001), but correlated positively to the change in stent volume (R = 0.52, P < 0.0001). By OCT, most CS struts were covered (100% [98.9, 100]) at the bifurcation site, whereas 61% of floating DES struts that crossed the sidebranch were covered by smooth tissue with a similar texture compared with neointima.

CONCLUSION

Although neointimal hyperplasia accumulates within the CS stent mainly 1-2 mm distal to the carina, the self-expanding CS stent may be effective in maintaining an adequate patency in the sidebranch by continued stent expansion noted at follow-up.

An intravascular ultrasound comparison of left anterior descending artery/first diagonal branch versus distal left main coronary artery bifurcation lesions

AIMS

We report the intravascular ultrasound (IVUS) analysis of plaque distribution in left anterior descending (LAD) artery/first diagonal (D1) and distal left main coronary artery (LMCA) bifurcation lesion location.

METHODS AND RESULTS

We reviewed 58 angiograms of LAD/D1 bifurcation lesions with pre-intervention IVUS of both the LAD and D1 and compared these data to a corresponding cohort (n=81) of LMCA bifurcations, dividing each bifurcation into three segments: MV (main vessel), MB (main branch distal to the carina), and SB (side branch). In the LAD/D1 cohort, D1 (SB) had less calcium and a smaller plaque burden compared to the other two segments. Continuous plaque from the LAD proximal to the carina (MV) into the LAD distal to the carina (MB) was seen in 90%, from the MV into the SB in 72%, and from the MV into both the MB and SB in 62%. In the LMCA cohort, ostial left circumflex (LCX) (SB) had less calcium and a smaller plaque burden compared to the distal LMCA (MV) and ostial LAD (MB). Continuous plaque from MV to MB was seen in 96%, from MV to the SB in 78%, and from MV to both branches in 74%.

CONCLUSIONS

The IVUS analysis of the LAD/D1 and LMCA bifurcations revealed that most lesions had diffuse plaques extending from the MV into the MB with the SB having the least amount of calcium and the smallest plaque burden, regardless of location.