Left Main Coronary Artery Bifurcation Research Articles

Spatiotemporally Mapped Endothelial Dysfunction at Bifurcations in a Coronary Artery‐on‐a‐Chip

AbstractAtherosclerotic plaques are commonly observed at low shear regions, in particular, the left main coronary artery (LMCA) bifurcation. Low shear regions at bifurcations promote endothelial dysfunction, a key factor initiating atherogenesis, however, mechanisms underlying this process are poorly understood. Dynamic in vitro models are critical to investigate endothelial dysfunction, but current static and vessels‐on‐chip systems typically lack physiologically complex geometries and local shear changes. Here, a bifurcating coronary artery‐on‐a‐chip is developed, mimicking the human LMCA, displaying reduced shear near the bifurcation, verified using computational fluid dynamics simulations. Over 7 days of dynamic culture, human coronary artery endothelial cells aligned with the flow and expressed more Endothelial nitric oxide synthase (eNOS) and intercellular cell adheison molecule‐1 (ICAM‐1) at high shear regions (12.7 dyn cm−2) adjacent to, but not at the bifurcation (0–3 dyn cm−2). After tumor necrosis factor‐alpha (TNFα) stimulation to induce endothelial dysfunction, spatially mapping cellular changes and shear gradients revealed cell alignment is disrupted over a larger area surrounding the bifurcation at a higher shear, and ICAM‐1 expression is increased closer to the bifurcation at a lower shear. This coronary artery‐on‐a‐chip establishes a system to spatially map endothelial cell behavior in response to differential shear and vessel geometry, enabling future studies into plaque initiation events, treatment targets, and drug screening.

Prognostic Impact of a Routine Six-Month Exercise Stress Test after Complex Left Main Bifurcation Percutaneous Intervention.

The prognostic value of exercise stress test after complex left main (LM) coronary artery bifurcation (LM) stenting has been poorly investigated. To partially fill this gap in knowledge, we retrospectively analyzed the procedural and medical data of consecutive patients referred to our center for complex LM bifurcation disease between January 2008 and May 2018 who were treated using either single- or dual-stenting techniques. The prognostic impact of an exercise stress test, performed 6 months after the coronary intervention, was evaluated in 502 patients (316 males, mean age 70.3 ± 12.8 years, mean Syntax score 31.6 ± 6.3). At follow up after a mean of 37.1 ± 10.8 months (range 22.1-47.3 months), the target lesion failure (TLF) rate was 10.1% while stent thrombosis and cardiovascular mortality were 1.2 and 3.6%, respectively. A positive exercise stress test was detected at 6-month follow up in 42 out of 502 patients (8.4%); the incidence of a significant restenosis was 7.6% (n = 38). Patients with a negative exercise stress test at 6-month follow up had higher freedom from TLF and improved survival compared to those with a positive exercise stress test.

“Ischemia in Upstream Neighborhood” After Plaque Modification with Intravascular Lithotripsy

Coronary artery calcification impacts outcomes after percutaneous coronary interventions owing to stent under expansion causing increased risk of stent thrombosis and restenosis. Therefore, adequate calcium modification before stent placement is the key to get desired outcomes in the patients with coronary artery calcification. Many devices are available for calcium modification, which includes orbital or rotational atherectomy, cutting balloon, scoring balloon, and intravascular lithotripsy. All these techniques have inherent risks of complications, such as coronary dissection, perforation, and slow or no reflow. We report a case of intravascular lithotripsy in calcified proximal left circumflex artery (LCX) lesion in a 63-year-old female leading to the left anterior descending artery (LAD) with no flow and ischemic ventricular tachycardia requiring DC cardioversion. Intravascular ultrasound from LAD revealed subintimal hematoma from ostium to mid LAD with intimal flap continuation into ostio-proximal LCX. The intimal flap in LAD has not showed any entry or exit tears which might increase the possibility of intramural hematoma shift to adjacent areas and branches leading to no reflow. Hence, cutting balloon fenestration of the intimal flap, followed by left main coronary artery bifurcation stenting was done to get a good result with flowing distal branches.

The impact of left circumflex coronary artery ostium stenosis on outcomes for patients after percutaneous coronary intervention for unprotected left main disease.

The impact of left circumflex coronary artery (LCX) ostium atherosclerosis in left main coronary artery (LM) bifurcation disease is not well-known. The study aimed to assess whether the involvement of LCX ostium carries prognostic implications in patients undergoing unprotected LM percutaneous coronary intervention (PCI). Consecutive 564 patients with unprotected LM (ULMCA) disease who underwent LM PCI between January 2015 and February 2021, with at least 1 year of available follow-up were included in the study. The first group was composed of 145 patients with ULMCA disease with LCX ostium stenosis, and the second group consisted of 419 patients with ULMCA disease without LCX ostium stenosis. Patients in the group with ULMCA disease with LCX ostium stenosis were significantly older and had more comorbidities. The two-stent technique was used more often in the group with LCX ostium stenosis (62.8% vs. 14.6%; P <0.001). During 7-year follow-up, all-cause mortality did not differ significantly between groups with and without LCX ostium stenosis (P = 0.50). The use of one-stent or two-stent technique also did not impact mortality in patients with LCX ostial lesions (P = 0.75). Long-term mortality subanalysis for three groups of patients: (1) patients with LM plus LCX ostium stenosis; (2) LM plus left anterior descending artery (LAD) ostium stenosis; (3) LM plus LCX ostium plus LAD ostium stenosis also did not differ significantly (P = 0.63). LCX ostium involvement in LM disease PCI is not associated with adverse long-term outcomes, which is highly beneficial for the Heart Team's decision-making process.

Effectiveness of using dual stent to intervene true left main coronary artery bifurcation lesions

Abstract: Lesions at the bifurcation of the left main coronary artery are dangerous lesions that account for approximately 4–8% of CAD (coronary artery disease) cases. In Vietnam, dual stent percutaneous coronary intervention has been used to treat true left main stem coronary artery bifurcation lesions, but there is no study that summarizes the recent results and evaluates them after a follow-up period. Consequently, we conducted this study.&#x0D; Research objectives: Effectiveness of using dual stent to intervene true left main coronary artery bifurcation lesions.[1]&#x0D; Objects and research methods: Crossectional study, review of all patients who received LMCA bifurcation lesions interventional stenting with dual stent at Hanoi Heart Hospital from 1/2018 to 6/2020.&#x0D; Research results: The rate of major cardiovascular events was determined as follow: 1 patient died during hospital stay; 18% of patients had at least one major cardiovascular event during the 12-month follow-up period; 3 patients had cerebrovascular accidents, which accounted for 6%; 3 patients had acute myocardial infarction, which accounted for 6%; and 2 patients had acute myocardial infarction, which accounted for 6%. Two patients require revascularization, representing 4% of the total population.

Single-stent strategy for left coronary artery bifurcation lesions in patients with chronic ischemic heart disease: protocol of a randomized trial

Aim. This study aims to compare the intraoperative, immediate postoperative and long-term postoperative results of stenting followed by final kissing balloon angioplasty (FKB) and without FKB for left coronary artery (LCA) bifurcation lesions in patients with chronic ischemic heart disease.Material and methods. We plan to perform an open-label, prospective, randomized, single-center, cohort trial that will include 40 patients with left main coronary artery bifurcation lesion, who will undergo stenting procedure followed by FKB or without FKB, using the second-generation drug-eluting stents. Randomization into two groups will be done after performing coronary angiography, confirming the inclusion criteria and the absence of non-inclusion criteria and signing a written consent in 2 copies. Group 1 — stenting followed by FKB. Group 2 — stenting without FKB. The total follow-up period is 24 weeks. It is planned to contact by phone on 30th and 180th day (±7 days) of postoperative period to obtain the information about patient condition, general survival rate, the events of combined controlled points and drug therapy. During 2d phone contact, on 180th day (±7 days), a patient will be invited to undergo multispiral computed tomography of the coronary arteries.The primary combined end-point: cardiac death, nonfatal myocardial infarction, acute cerebrovascular accident and the repeat target vessel revascularization. The secondary combined end-point: thrombosis and stent restenosis.Conclusion. Our study will optimize the approach to the choice of stenting strategy (with or without FRB) for left main coronary artery bifurcation lesions in patients with chronic ischemic heart disease.

Multimodal Imaging of a Culotte Bifurcation Procedure in the Left Main Coronary Artery of a Perfusion-Fixed Human Heart: Step-by-Step with Serial Micro-CT Analyses

Percutaneous coronary intervention can be a high-risk procedure that would benefit from optimizing device-tissue interactions between stents and coronary vessels. Using a perfusion-fixed human heart with coronary artery disease, we performed a percutaneous coronary intervention of the left main coronary artery bifurcation. This heart was perfused and multimodal imaging was utilized to view the procedure with direct visualization, fluoroscopy, and optical coherence tomography (OCT). We followed the European Bifurcation Club’s guidelines to perform a single-stent bifurcation before transitioning to a two-stent Culotte technique. After each procedural step, the heart was removed from the perfusion apparatus and transferred to a micro-CT scanner to obtain unique scans. We conducted apposition analyses of the computational 3D models from micro-CT DICOM datasets, and compared them to the results from direct visualization and commercial OCT’s Apposition Indicator software. Additional measurements of resulting coronary anatomic expansions were taken to determine the potential roles of each step in improving procedural outcomes.Graphical Micro-CT images show stent deformation during a percutaneous coronary intervention(provisional to Culotte bifurcation procedure) in an isolated diseased human heart.

Coronary computed tomography angiography assessment of relationship between right coronary artery-aorta angle and the development of coronary artery disease.

Whilst a correlation has been established between wide left main coronary artery bifurcation [left anterior descending-left circumflex (LAD-LCx)] angle (>80°) and the development of coronary artery disease (CAD), this retrospective, causal-comparative pilot study aimed to explore whether a relationship exists between right coronary artery (RCA)-aorta angle and CAD. Thirty normal cases were identified via radiology reports and selected as the control group with coronary computed tomography angiography (CCTA) scans performed on a 320-slice computed tomography (CT) scanner. Thirty CAD cases were selected with invasive coronary angiography performed to confirm the degree of stenosis, and CCTA performed on dual source and 320-slice CT scanners. An independent sample t-test was used to compare the differences in coronary angles between the normal and CAD group, and analysis of variance (ANOVA) was used to assess for significant differences between coronary angles in normal and CAD subgroups. Coronary angle measurements were conducted by two independent assessors with high intraclass correlation (r=0.971-0.998, P<0.001). RCA-aorta angle measurements were significantly larger in the normal group [87.47°, 95% confidence interval (CI): 79.31° to 95.78°] compared to the CAD group (76.82°, 95% CI: 67.82° to 85.61°, P=0.05). No significant difference was found between RCA-aorta angle and degree of coronary stenosis (P=0.75). This study suggests a relationship between narrow RCA-aorta angle and CAD.

Provisional Vs Dual Stenting of Left Main Coronary Artery Bifurcation Lesions

Background: The primary LMCA stenting methods used nowadays consist of single stent (provisional), and two stent (T and protrusion, and double kissing crush {DK crush}, culotte, or classic crush). The optimal technique for bifurcation lesion treatment for the patients present with distal ULMCA disease is still unclear and not much is known about the best course of action and the clinical outcomes following various PCI techniques for ULMCA bifurcations in Pakistan. Objective: To investigate the midterm (3-year) outcomes related to the provisional stenting compared to two-stenting technique for the bifurcations of ULMCA undergoing the percutaneous coronary intervention. Methodology: A single-center retrospective, non-randomized cohort study was conducted during the period from March 2021 to August 2022 including all the consecutive LM bifurcation lesions. The patients attending Punjab Institute of Cardiology, Lahore were divided into two groups, depending upon the treatment received. One group underwent PCI with provisional stenting technique while the other underwent 2-stent PCI. The groups were compared for procedural success and 3-year clinical outcomes. Data was analyzed using SPSS. Results: The success rate of left main bifurcation angiography was comparable between both the techniques (2-stent 93.6 % vs. Provisional 92.1 %, P = 0.62). MACE rates were comparable between groups at 1, 2, and 3 years (PS 3.0 % vs. Dual stent 2.4 %, p = 0.75 at 1-year, PS 4.8 % vs. Dual stent 8 %, p = 0.26 at 2-years, and PS 10.2 % vs. Dual stent 12 % at 3-years, p = 0.62). Conclusion: Two stenting strategy was linked to same rates of MACEs at the 3-year duration in comparison to the single stenting technique (PS 10.2 % vs. 2-Stent 12 %, p=0.62) and both the dual and single provisional stent techniques have comparable angiographic success rate for LM bifurcation lesions.

Left Main Coronary Artery Bifurcation Lesions: Two Stents vs One Stent Strategy-Comparison of Major Adverse Cardiac Events (MACE) at 2 years

Objective: To evaluate the long-term clinical results for a one-stent (1S) strategy compared to a two-stent (2S) strategy in distal unprotected left main coronary artery (ULMCA) bifurcation disease.&#x0D; Study Design: Comparative Cross-sectional study.&#x0D; Place and Duration of Study: Armed Forces Institute of Cardiology, Rawalpindi Pakistan, from Jan 2019 to Apr 2020.&#x0D; Methodology: 1-S approach was defined as stenting of the main vessel only and 2-S approach as stenting side branch and main vessel. Individual undergoing LMCA intervention were included via consecutive sampling in the study. Stent Crossover approach was used in 1-S technique; whereas, DK crush, culotte, and T-stenting approaches were employed in individuals who were treated with a 2-S approach. A composite of major adverse cardiovascular event (MACE) i.e., myocardial infarction, stroke or death and target lesion revascularization (TLR) were considered as primary end-point.&#x0D; Results: A sum of 110 individuals were inducted, 74 of them had stenting of left main bifurcation using a 1-S approach; and 36 patients underwent a 2-S PCI. Average age of the patients included in the study was 63.9±10.8 years. In 1 stent subset, the success rate of procedure was 99% whereas 100% success rate was seen in 2-S group. During the 2-year duration of follow up,frequency of MACE in single stent subset was (5.4%) whereas it was (13.8%, p=0.253) in the 2-S subset.&#x0D; Conclusion: When compared to 2-S approach of distal left main stenting, a 1-S strategy appears to demonstrate optimal clinical results and 2-year survival free of MACE. Choosing appropriate interventional strategy has proven prognostically significant; so, it demands mindful approach selection.

Provisional Versus Dual Stenting of Left Main Coronary Artery Bifurcation Lesions (from a Comprehensive Meta-Analysis)

The optimal technique for bifurcation of left main coronary artery (LMCA) stenting has been a subject of controversy since the inception of drug-eluting stents. We searched PubMed, Clinical Trials Registry, and the Cochrane Central Register of Controlled Trials from January 2002 through October 2021. A total of 13 studies comparing the use of provisional versus dual stenting in patients with LMCA bifurcation lesions were included. Any major adverse cardiac event (MACE) was considered the primary composite end point. The secondary end points included individual components of MACE, including death, myocardial infarction, and target lesion revascularization. The treatment effect was defined as the log odds ratio (OR) of provisional over dual stenting for cumulative event rate at 3 years. In 12 studies with 8,377 patients included for MACE, the use of a provisional-stenting strategy was associated with a significant reduction of 3-year MACE (OR 0.64, 95% confidence interval [CI] 0.46 to 0.88) compared with a dual-stenting strategy, primarily driven by target lesion revascularization (OR 0.51, 95% CI 0.36 to 0.73). No significant difference was found regarding death (OR 0.88; 95% CI 0.65 to 1.21) or myocardial infarction (OR 0.97, 95% Cl 0.61 to 1.54). In conclusion, our meta-analysis suggests that provisional stenting should be the preferred technique over dual stenting when treating LMCA bifurcation lesions with drug-eluting stents. Further randomized controlled studies compounded with intracoronary imaging comparing the 2 strategies are warranted.

A Review of Double Kissing Crush Stenting in Coronary Bifurcation Lesions

Double kissing (DK) crush stenting for coronary bifurcation lesions has gain popularity worldwide because of its superior randomized studies data and excellent clinical outcomes. This review evaluates all DK crush clinical trials and studies. It also reveals the contemporary technique steps by steps as well as the trouble shooting with illustrated clinical scenarios. Among all the available evidence, the DK crush technique is superior when compared to the provisional stenting technique for complex bifurcation lesion. DK crush stenting provides the best evidence-based approach to complex bifurcation lesions especially the left main coronary artery bifurcation lesions. Future direction of how to make this DK crush technique better is also proposed.

Safety Assessment of Microcatheter-Protected Rotational Atherectomy with the Double Guiding Catheter Technique for Severely Calcified Left Main Bifurcation.

Background Rotational atherectomy (RA) is a tool for calcium modification, but there is a risk of losing the side branch in left main coronary artery (LM) bifurcation lesions, resulting in disastrous consequences. Microcatheter-protected RA with the double guiding catheter (GC) technique for severely calcified LM bifurcations has been described previously, but its safety warrants further investigation. Methods Various sizes of coronary calcification vascular simulators were utilized to model calcified LM bifurcation lesions for RA in in vitro. The damage to the side branch protective microcatheters and guidewires was accessed after microcatheter-protected RA with the double GC technique. In clinical practice, microcatheter-protected RA with the double GC technique was carried out in two patients. Results In vitro, none of the protective microcatheters or guidewires were completely fractured, although the majority of them were damaged to varying degrees. In clinical practice, we successfully carried out two cases of percutaneous coronary intervention for severely calcified LM bifurcation with microcatheter-protected RA using the double GC technique. Conclusion RA of severely calcified LM bifurcation lesions may be successfully performed using microcatheter-protected RA with the double GC technique, potentially reducing the risk of side branch occlusion. Since majority of protective microcatheters or guidewires were damaged, there was still some risk, and it is recommended to use this technique only in highly selected patient population of severely calcified true (Medina 1, 1, 1) LM bifurcations.

P429 PROGNOSTIC IMPACT OF ROUTINE SIX–MONTH EXERCISE STRESS TEST AFTER COMPLEX LEFT MAIN BIFURCATION PCI

Abstract Background/Aim The prognostic value of the exercise stress after complex stenting of left main (LM) coronary artery bifurcations (LM) disease has been poorly investigated in the modern era. Methods We retrospectively analysed the procedural and medical data of patients referred to our center for complex LM bifurcation diseas, treated using either single versus dual stenting [Cross–over provisional stenting, T or T–and–Protrusion (TAP), Culotte, and Nano–inverted–T (NIT)] techniques between January 2008 to May 2018. The prognostic impact of an exercise test performed at 6 months during the follow–up period. Results Five hundred and two patients (316 males, mean age 70.3±12.8 years, mean Syntax score 31.6±6.3) were evaluated. At a mean follow–up of 37.1±10.8 months (range 22.1–47.3 moths), Target lesion failure (TLF) rate was 10.1%. Stent thrombosis and cardiovascular mortality were observed in 1.2% and 3.6% of cases, respectively. A positive exercise test at 6 months of follow–up was detected in 42 out of 502 patients (8.4%) and correlated with angiographic restenosis in 38 patients (7.6%): 7/171patients in Cross–over group (4.1%), 10/61 patients in T or TAP group (16.4%), 15/98 patients in Culotte group (15.3%) and 6/172 patients in NIT group (3.5%). Multivariate Cox regression analysis demonstrated that Age &amp;gt; 75 years (HR 1.45, 95% CI: 1.33–1.58, p = 0.03), dyslipidaemia (HR: 1.68, 95% CI: 1.58–1.72, p &amp;lt; 0.001), eGFR&amp;lt;30 ml/min/1.73 m2 (HR: 1.44, 95% CI: 1.38–1.52, p = 0.04), presence of a triple vessel disease (HR: 1.89, 95% CI: 1.89, 95% CI: 1.84–1.93, p &amp;lt; 0.001), additional ostial LM lesion (HR: 1.75, 95% CI: 1.76–1.81, p &amp;lt; 0.001), additional LM body lesion (HR: 1.33, 95% CI: 1.28–1.36, o &amp;lt; 0.001), a Syntax score &amp;gt; 25 (HR:1.67, 95% CI: 1.61–1.76, p = 0.01), need of Rotablator (HR: 1.66, 95% CI: 1.61–1.75, p = 0.02) and the number of stents implanted (HR: 1.12, 95% CI: 1.08–1.16, p &amp;lt; 0.001) were independent predictors of a positive stress test. Patients reporting a negative exercise test at 6 months of follow–us had a higher freedom from TLF and improved survival compared to those with positive exercise stress test (Figure 1 Panels A and B). Conclusions A negative exercise performed after 6 months from complex left main stenting predicted excellent outcomes at 3 years follow–up.

Absolute zero-contrast percutaneous coronary intervention under intravascular ultrasound guidance in chronic kidney disease patients - From despair to hope?

Zero contrast percutaneous coronary intervention (PCI) reduces contrast induced acute kidney injury (CI-AKI), and it improves the outcome of chronic kidney disease (CKD) patients undergoing PCI. We sought to assess the safety and short-term outcomes of 'absolute' zero-contrast PCI under intravascular ultrasound (IVUS) guidance in CKD patients. Data from all consecutive CKD patients who were included for absolute zero contrast PCI during the period of June 2020 to March 2021 were included in this analysis. Clinical characteristics, angiographic, IVUS and procedural data, and follow-up data were analyzed. Totally 42 patients (66 vessels) with the mean age of 69.04±11.9years, were included for absolute zero-contrast PCI. The mean serum creatinine and estimated glomerular filtration rate (eGFR) were 2.67±1.46 mgs% and 30.67±12.26ml/min/1.73m2 respectively. The most common presentation was acute coronary syndrome (ACS) and the mean left ventricular ejection fraction (LVEF) and SYNTAX score were 43.7±11.9% and 27.7±14.1 respectively. Complex PCI including 14 (21.2%) left main coronary artery (LMCA) PCI (seven LMCA bifurcation PCI) and three chronic total occlusion (CTO) PCI were also done. Technical success was 92.4% without any major complications. Two patients died of non cardiac causes on follow up (3-12months), and all the remaining were symptom free. IVUS guided 'absolute' zero-contrast PCI is feasible and safe CKD patients. Even in complex lesion morphologies, the procedure can be completed without any contrast and complications.

Clinical outcomes of left main percutaneous coronary intervention in elderly patients at a long-term follow-up

Abstract Funding Acknowledgements Type of funding sources: None. Introduction The progressive aging of the population leads to higher prevalence of ischemic heart disease with an increased left main coronary artery (LMCA) disease. Elderly patients (&amp;gt;75 years) represent an unfavorable subgroup because of their fragility, the frequent presence of multiple comorbidities associated and their especially high rate of surgical risk. Purpose The main objective of this study was to evaluate the efficacy and safety of percutaneous coronary interventions (PCI) in LMCA disease at 14 years follow-up in the elderly. Methods We prospectively included 217 consecutive patients (80.3 ± 2.4 years, 68.7% male) with LMCA disease treated with PCI between June 2006 and June 2020. We evaluated the occurrence of major adverse cardiovascular events (MACE) defined as cardiac death, non-fatal myocardial infarction, target lesion revascularization (TLR) and stent thrombosis after 14 years clinical follow-up (median 56 months). Results 48.4% of patients had stable coronary disease and 51.6% acute coronary syndrome (42.4% Non-STEMI and 9.2% STEMI). 43.3% were diabetic patients and 45.9% presented moderate-severe left ventricular systolic dysfunction. Mean logistic EuroSCORE was 10.4% and 47.5% of lesions with Syntax score ≥ 32. LMCA bifurcation was affected in 78.8% of cases and the most frequently bifurcation technique employed was "provisional stenting" in 64.1% of cases. Second-generation drug eluting stent was used in 97.6% of cases. The intraprocedural complication rate was 4.5% with one death. During follow-up, MACE rate at 14 years was 19.9% (14.7% cardiac death, 3.2% non-fatal myocardial infarction, 4.1% TLR and thrombosis rate 0.5%). There were significant differences in the occurrence of MACE in patients with moderate-severe ventricular systolic dysfunction (p=0.01 OR 3.92; IC 95% de 1.26-8.57). Conclusions Left main PCI in elderly patients with high surgical risk provide very favourable results with a low rate of immediate complications in the procedure and a low rate of cardiac adverse events at a very long-term follow-up. However, patients with ventricular dysfunction have poor prognosis.

Napkin ring formation in culotte stenting using current-generation drug-eluting stents in left main coronary artery bifurcation.

Napkin ring formation in culotte stenting using current-generation drug-eluting stents in left main coronary artery bifurcation.

Accuracy of vascular tortuosity measures using computational modelling

Severe coronary tortuosity has previously been linked to low shear stresses at the luminal surface, yet this relationship is not fully understood. Several previous studies considered different tortuosity metrics when exploring its impact of on the wall shear stress (WSS), which has likely contributed to the ambiguous findings in the literature. Here, we aim to analyze different tortuosity metrics to determine a benchmark for the highest correlating metric with low time-averaged WSS (TAWSS). Using Computed Tomography Coronary Angiogram (CTCA) data from 127 patients without coronary artery disease, we applied all previously used tortuosity metrics to the left main coronary artery bifurcation, and to its left anterior descending and left circumflex branches, before modelling their TAWSS using computational fluid dynamics (CFD). The tortuosity measures included tortuosity index, average absolute-curvature, root-mean-squared (RMS) curvature, and average squared-derivative-curvature. Each tortuosity measure was then correlated with the percentage of vessel area that showed a < 0.4 Pa TAWSS, a threshold associated with altered endothelial cell cytoarchitecture and potentially higher disease risk. Our results showed a stronger correlation between curvature-based versus non-curvature-based tortuosity measures and low TAWSS, with the average-absolute-curvature showing the highest coefficient of determination across all left main branches (p < 0.001), followed by the average-squared-derivative-curvature (p = 0.001), and RMS-curvature (p = 0.002). The tortuosity index, the most widely used measure in literature, showed no significant correlation to low TAWSS (p = 0.86). We thus recommend the use of average-absolute-curvature as a tortuosity measure for future studies.

The Drug Coated Balloon-Only Strategy for Treatment of de Novo Left Main Coronary Artery Bifurcation Lesion: Stentless Strategy.

The study aimed to evaluate the efficacy and safety of drug coated balloon-only strategy (DCB-only) in the treatment of de novo left main coronary artery (LM) bifurcation lesions. 85 patients were enrolled in this study and classified them into two groups: DCB-only group (n = 36) and DES group (n = 49). The MLD of target vessels was measured before and immediately after percutaneous coronary intervention (PCI) and late luminal loss (LLL) were also calculated. And the occurrence of major adverse cardiovascular events (MACE) was also evaluated. Compared with that before PCI, the MLD of target lesions significantly increased immediately after PCI (P < .05) and no MACE was recorded during the perioperative period both in two groups. The MLD at follow-up was significantly higher than that before both DCB and DES treatment. Compared with the DES group, the MLD of the DCB group was smaller than immediately after PCI in the LM and LAD (P < .05). The LLL of LAD in DCB group was smaller than that in DES group (P < .05). There was no significant difference in the incidence of luminal restenosis at the target lesion between the two groups, and no significant difference in the incidence of MACE (P > .05). The use of DCB-only to treat de novo LM bifurcation lesions is effective and relatively safe, which provides new ideas for the treatment of LM coronary artery bifurcation lesions in the future.

A Case Summary of the Application of a Drug-Eluting Stent Combined with a Drug-Coated Balloon in Left Main Coronary Artery Disease

Objective: To evaluate the clinical efficacy of a drug-eluting stent (DES) combined with a drug-coated balloon (DCB) in the treatment of left main coronary artery bifurcation lesions. Methods: A retrospective analysis was conducted on the clinical data of eight patients with left main coronary artery bifurcation lesions treated with a DES combined with a DCB who were admitted to our hospital from July 2016 to July 2017. These eight patients all underwent DES treatment for their left main coronary artery and left anterior descending coronary artery lesions, and DCB treatment at the ostium of the left circumflex artery; six of the patients underwent surgical procedures under the guidance of intravascular ultrasonography. Immediate postoperative angiography was used to evaluate the patency of the diseased vessels, and the restenosis rate at the 6-month follow-up after the operation and the incidence of serious clinical events within 6 months were assessed as well. Results: The use of a DES combined with a DCB in the treatment of left main coronary artery bifurcation lesions had a low restenosis rate (left main coronary artery (8.4 ± 5.3)%, left anterior descending coronary artery (18.2 ± 5.0)%, left circumflex artery (30.5 ± 16.5)%). No serious clinical events occurred in any patients. Conclusion: A DES combined with a DCB is a safe and effective interventional treatment for left main artery coronary bifurcation lesions.