BOOM: A novel bifurcation stent technique using optical coherence tomography co-registration.

BACKGROUND/PURPOSE: Bifurcation lesions comprise 20 % of percutaneous coronary interventions (PCI) and are associated with worse long-term outcomes. With an increasing percentage of patients presenting with complex anatomy, including bifurcation disease, there is a need for treatment strategies to optimize PCI outcomes. METHODS/MATERIALS: We retrospectively analyzed 48 patients undergoing OCT guided bifurcation PCI using the 'Bifurcation and Ostial OCT Mapping' (BOOM) technique. The primary efficacy variable studied was stent precision following deployment, defined as the distance of the most proximal stent strut from the true ostium of the target vessel. Additionally, targeted follow-up occurred by phone at 6- and 12-months post procedure, where the frequency of myocardial infarction, target lesion revascularization, target vessel and non-target vessel revascularization, and mortality were collected. RESULTS: A total of 40 (83.3 %) had an ostial lesion that required treatment while the remaining patients had true bifurcation disease. Most target lesions were in either the LAD or its branches (29 lesions (60.3 %)). With respect to stent positioning, the median absolute geographic miss, (i.e., stent protrusion into the main branch or lack of complete ostial stent coverage), was 0.75 mm. At 6 months, one patient required target lesion revascularization with no additional patients at 12 months. CONCLUSIONS: BOOM is a safe and simple strategy that can be a useful technique to optimize precise stent placement for ostial and bifurcation lesions.

Advanced CT Imaging for the Assessment of Calcific Coronary Artery Disease and PCI Planning.

Vascular calcification is a hallmark of atherosclerosis and adds considerable challenges for percutaneous coronary intervention (PCI). This review underscores the critical role of coronary computed tomography (CT) angiography in assessing and quantifying vascular calcification for optimal PCI planning. Severe calcification significantly impacts procedural outcomes, necessitating accurate preprocedural evaluation. We describe the potential of coronary CT for calcium assessment and how CT may enhance precision in device selection and procedural strategy. These advancements, along with the ongoing Precise Procedural and PCI Plan study, represent a transformative shift toward personalized PCI interventions, ultimately improving patient outcomes in the challenging landscape of calcified coronary lesions.

Off-Label Use of Peripheral Paclitaxel Drug-Coated Balloons in Management of Recurrent Coronary In-Stent Restenosis.

Background: While not available for clinical use in the United States, dedicated drug-coated balloons (DCB) are currently under investigation for the management of coronary in-stent restenosis (ISR). Peripheral drug-coated balloons (P-DCB) have been used off-label for coronary ISR. Further data regarding this practice are needed. We aimed to describe outcomes in patients who underwent off-label P-DCB angioplasty for coronary ISR. Methods: We analyzed data on P-DCB angioplasty for coronary ISR at a single high-volume center between April 1, 2015, and December 30, 2017. Demographic and procedural details were collected, with systematic follow-up as clinically indicated. Results: Data from 31 patients treated with P-DCB angioplasty (mean age 68.0 ± 10.7 years) with coronary ISR (17 recurrent and 14 first time) were analyzed. Most patients presented with high-grade angina (81%) or myocardial infarction (13%). Treated ISR lesions were in native coronary arteries (68%), saphenous vein grafts (SVG, 23%), and the left internal mammary artery (10%). Diffuse intrastent ISR was common (69%) with a mean lesion length of 21.7 ± 12.4 mm. No postprocedural myocardial infarction occurred and 1 nonprocedural mortality occurred during index admission. At follow-up (median: 283, interquartile range [IQR]: 354 days), repeat angiography was performed in 19 patients (median: 212, IQR: 188 days), and 11 patients had target lesion recurrent ISR (Kaplan-Meier event-free survival estimate: 44.7%, 95% CI, 26.1%-76.5%). Conclusions: In the absence of availability of dedicated coronary DCB, treatment of coronary ISR using P-DCB angioplasty was feasible, although follow-up demonstrated continued risk for recurrent ISR in this high-risk population.

A Systematic Approach to the Evaluation of the Coronary Microcirculation Using Bolus Thermodilution: CATH CMD.

Coronary microvascular dysfunction (CMD) can cause myocardial ischemia in patients presenting with angina without obstructive coronary artery disease (ANOCA). Evaluating for CMD by using the thermodilution technique offers a widely accessible means of assessing microvascular resistance. Through this technique, 2 validated indices, namely coronary flow reserve and the index of microcirculatory resistance, can be computed, facilitating investigation of the coronary microcirculation. The index of microcirculatory resistance specifically estimates minimum achievable microvascular resistance within the coronary microcirculation. We aim to review the bolus thermodilution method, outlining the fundamental steps for conducting measurements and introducing an algorithmic approach (CATH CMD) to systematically evaluate the coronary microcirculation. Embracing a standardized approach, exemplified by the CATH CMD algorithm, will facilitate adoption of this technique and streamline the diagnosis of CMD.

Retrospective Multicenter Analysis of Intravascular Lithotripsy Use During Calcified Left Main Coronary Artery Percutaneous Coronary Interventions.

Background: Intravascular lithotripsy (IVL) safely and effectively modifies calcified coronary lesions during percutaneous coronary interventions (PCI). Data regarding its utility in modifying calcified left main coronary artery (LMCA) disease are limited. This study aimed to evaluate short-term outcomes of IVL-assisted LMCA PCI. Methods: This retrospective multicenter all-comers study analyzed patients who underwent intravascular imaging-guided, IVL-assisted PCI for calcified LMCA disease. Clinical and procedural characteristics were obtained, including intravascular imaging measurements. Technical success was defined as successful stent deployment with <30% residual diameter stenosis. Major adverse cardiac events (MACE) was a composite of all-cause death, myocardial infarction, and target vessel revascularization evaluated immediately postprocedure and at 30-day follow-up. Results: Among 184 patients treated at 7 centers from 2019-2023, IVL-assisted LMCA PCI achieved 99.4% technical success. Calcium fracture was identified in 136/165 cases (82.4%) on post-IVL imaging. Pretreatment minimal luminal area increased significantly compared to post-PCI minimal stent area (MSA) (4.1 ± 1.3 to 9.3 ± 2.5 mm2, respectively; P < .001). There was a direct correlation between IVL balloon size and the final MSA (P = .002). In-hospital MACE was 4.4% and 30-day MACE was 8.8%. In multivariate logistic regression, presentation with troponin-positive myocardial infarction was the sole predictor of 30-day MACE. Conclusions: IVL-assisted PCI for calcified LMCA lesions was safe and resulted in high technical success rates, confirming its utility as an effective treatment in this challenging lesion subset.

A hierarchical optimization approach to maximize hosting capacity for electric vehicles and renewable energy sources through demand response and transmission expansion planning.

Within the scope of sustainable development, integrating electric vehicles (EVs) and renewable energy sources (RESs) into power grids offers a number of benefits. These include reducing greenhouse gas emissions, diversifying energy sources, and promoting the use of green energy. Although the literature on hosting capacity (HC) models has grown, there is still a noticeable gap in the discussion of models that successfully handle transmission expansion planning (TEP), demand response (DR), and HC objectives simultaneously. Combining TEP, DR, and HC objectives in one model optimizes resource use, enhances grid stability, supports renewable and EV integration, and aligns with regulatory and market demands, resulting in a more efficient, reliable, and sustainable power system. This research presents an innovative two-layer HC model, including considerations for TEP and DR. The model determines the highest degree of load shifting appropriate for incorporation into power networks in the first layer. Meanwhile, the second layer focuses on augmenting the RES and EVs' hosting capability and modernizing the network infrastructure. System operators can choose the best scenario to increase the penetration level of EVs and RESs with the aid of the proposed model. The proposed model, which is formulated as a multi-objective mixed-integer nonlinear optimization problem, uses a hierarchical optimization technique to identify effective solutions by combining the particle swarm optimization algorithm and the crayfish optimizer. When compared to traditional methods, the results obtained from implementing the proposed hierarchical optimization algorithm on the Garver network and the IEEE 24-bus system indicated how effective it is at solving the presented HC model. The case studies demonstrated that integrating DR into the HC problem reduced peak load by 10.4-23.25%. The findings also highlighted that DR did not impact the total energy consumed by EVs throughout the day, but it did reshape the timing of EV charging, creating more opportunities for integration during periods of high demand. Implementing DR reduced the number of projects needed and, in some cases, led to cost savings of up to 12.3%.

From Triumph to Trial: A Case Study of Non-Tuberculous Mycobacterium After Tetralogy of Fallot (TOF) Correction in an Immunocompetent Child.

Mycobacterium simiae, a slow-growing non-tuberculous mycobacterium (NTM), presents diagnostic challenges due to its resemblance to Mycobacterium tuberculosis and other NTMs. While NTM infections and tuberculosis share clinical and radiological features, their management strategies differ. Accurate differentiation is pivotal, as misdiagnosing NTM infections such as MDR-TB can lead to ineffective treatments. A case involving an 11-year-old female with tetralogy of Fallot (TOF) and a pulmonary M. simiae infection underscores the importance of precise diagnosis. Enhancing diagnostic methods is imperative to prevent mismanagement of NTM infections and ensure appropriate care.

Paclitaxel-coated versus sirolimus-coated balloon angioplasty for coronary artery disease: A systematic review and meta-analysis.

BACKGROUND: Although use of sirolimus-based analogs has shown superiority over paclitaxel in drug-eluting stents, the relative efficacy of these two agents released from drug-coated balloons (DCB) is unclear. The present meta-analysis is aimed to compare outcomes after percutaneous coronary intervention (PCI) with paclitaxel-coated balloons (PCB) versus sirolimus-coated balloons (SCB) for either in-stent restenosis or native de novo lesions. METHODS: The study outcomes were 1) target lesion failure (TLF), a composite of cardiac death, target vessel myocardial infarction, or target lesion revascularization, and 2) follow-up angiographic parameters including late lumen loss (LLL), diameter stenosis, and minimal lumen diameter (MLD). Pooled odds ratios (OR) and weighted mean differences (WMD) with 95% confidence intervals (CI) were calculated by using random-effects models. RESULTS: A search of PubMed, EMBASE, and Cochrane Library from their inception to January 2024 identified five randomized clinical trials and three observational studies with a total of 1861 patients (889 in PCB and 972 in SCB groups). During 9-12 months of follow-up, there was no significant difference in TLF (OR 1.01, 95% CI 0.75-1.35) between the two groups. On follow-up angiography at 6-9 months, MLD (WMD 0.10, 95% CI 0.02-0.17) was larger in PCB but there was no statistically significant difference in LLL (WMD -0.11, 95% CI -0.23-0.02) and diameter stenosis (WMD -3.33, 95% CI -8.11-1.45). CONCLUSIONS: Among patients undergoing DCB-only PCI, the risk of TLF was similar during 9-12 months of follow-up after PCB and SCB treatment. However, the MLD was larger favoring PCB over SCB on follow-up angiography.

Integrated transmission expansion planning incorporating fault current limiting devices and thyristor-controlled series compensation using meta-heuristic optimization techniques.

Transmission expansion planning (TEP) is a vital process of ensuring power systems' reliable and efficient operation. The optimization of TEP is a complex challenge, necessitating the application of mathematical programming techniques and meta-heuristics. However, selecting the right optimization algorithm is crucial, as each algorithm has its strengths and limitations. Therefore, testing new optimization algorithms is essential to enhance the toolbox of methods. This paper presents a comprehensive study on the application of ten recent meta-heuristic algorithms for solving the TEP problem across three distinct power networks varying in scale. The ten meta-heuristic algorithms considered in this study include Sinh Cosh Optimizer, Walrus Optimizer, Snow Geese Algorithm, Triangulation Topology Aggregation Optimizer, Electric Eel Foraging Optimization, Kepler Optimization Algorithm (KOA), Dung Beetle Optimizer, Sea-Horse Optimizer, Special Relativity Search, and White Shark Optimizer (WSO). Three TEP models incorporating fault current limiters and thyristor-controlled series compensation devices are utilized to evaluate the performance of the meta-heuristic algorithms, each representing a different scale and complexity level. Factors such as convergence speed, solution quality, and scalability are considered in evaluating the algorithms' performance. The results demonstrated that KOA achieved the best performance across all tested systems in terms of solution quality. KOA's average value was 6.8% lower than the second-best algorithm in some case studies. Additionally, the results indicated that WSO required approximately 2-3 times less time than the other algorithms. However, despite WSO's rapid convergence, its average solution value was comparatively higher than that of some other algorithms. In TEP, prioritizing solution quality is paramount over algorithm speed.

Intravascular imaging-guided percutaneous coronary intervention for heavily calcified coronary lesions: a systematic review and meta-analysis.

Although multiple randomized clinical trials (RCTs) have shown that intravascular imaging (IVI)-guided percutaneous coronary intervention (PCI) is associated with improved clinical outcomes compared with angiography-guided PCI, its benefits specifically in calcified coronary lesions is unclear due to the small number of patients included in individual trials. We performed a meta-analysis of RCTs to investigate benefits of IVI-guided PCI compared with angiography-guided PCI in heavily calcified coronary lesions. The primary endpoint was major adverse cardiac events (MACE), a composite of cardiac death, target-vessel or target-lesion myocardial infarction, and target-vessel or target lesion revascularization. Pooled odds ratios (OR) and 95% confidence intervals (CI) were calculated by using a random-effects meta-analysis based on the restricted maximum likelihood method. A search PubMed, EMBASE, and Cochrane Library from their inception to January 2024 identified 4 trials that randomized 1319 patients with angiographically moderate or severe or severe coronary calcification to IVI-guided (n = 702) vs. angiography-guided PCI (n = 617). IVI-guided PCI resulted in a significantly lower odds of MACE (OR 0.57, 95% CI 0.40-0.80) compared with angiography-guided PCI at a weighted median follow-up duration of 27.3 months. There was no evidence of heterogeneity among the studies (I2 = 0.0%), and included trials were judged to be low risk of bias. Compared with angiography-guided PCI, IVI-guided PCI was associated with a significantly lower MACE in angiographically heavily calcified coronary lesions.

Outcomes of ultra-low contrast percutaneous coronary intervention in patients with advanced chronic kidney disease.

BACKGROUND: Coronary angiography and percutaneous coronary intervention (PCI) in patients with chronic kidney disease (CKD) is associated with increased risk of contrast induced nephropathy (CIN) and requirement for renal replacement therapy (RRT). OBJECTIVES: We aimed to evaluate our single center experience of ultra-low contrast PCI in patients with CKD and to characterize 1 year outcomes. METHODS: We performed a retrospective analysis of ultra-low contrast PCI at our institution between 2016 and 2022. Patients with CKD3b-5 (eGFR <45 mL/min/1.73m2), not on RRT who underwent ultra-low contrast PCI ( < 30 mL of contrast during PCI) were included. Primary outcomes included change in eGFR post-procedurally, and death, RRT requirement, and major adverse cardiac events (MACE) at 1 year follow-up. RESULTS: One hundred patients were included in the study. The median age was 67 years old and 28% were female. The median baseline eGFR was 21.5 mL/min/1.73m2 (IQR 14.08-32.0 mL/min/1.73m2). A median of 8.0 mL (IQR 0-15 mL) of contrast was used during PCI. Median contrast use to eGFR ratio was 0.37 (IQR 0-0.59). There was no significant difference between pre-and postprocedure eGFR (p = 0.84). At 1 year, 8% of patients died, 11% required RRT and 33% experienced MACE. The average time of RRT initiation was 7 months post-PCI. Forty-four patients were undergoing renal transplant evaluation, of which 17 (39%) received a transplant. CONCLUSIONS: In patients with advanced CKD, ultra-low contrast PCI is feasible and safe with minimal need for peri-procedural RRT. Moreover, ultra-low contrast PCI may allow for preservation of renal function in anticipation of renal transplantation.

Calcified Nodule in Percutaneous Coronary Intervention: Therapeutic Challenges.

Calcified nodules (CNs) are among the most challenging lesions to treat in contemporary percutaneous coronary intervention. CNs may be divided into 2 subtypes, eruptive and noneruptive, which have distinct histopathological and prognostic features. An eruptive CN is a biologically active lesion with a disrupted fibrous cap and possibly adherent thrombus, whereas a noneruptive CN has an intact fibrous cap and no adherent thrombus. The use of intravascular imaging may allow differentiation between the 2 subtypes, thus potentially guiding treatment strategy. Compared with noneruptive CNs, eruptive CNs are more likely to be deformable, resulting in better stent expansion, but are paradoxically associated with worse clinical outcomes, in part because of their frequent initial presentation as an acute coronary syndrome and subsequent reprotrusion of the CN into the vessel lumen through the stent struts. Pending the results of ongoing studies, a tailored therapeutic approach based on the distinct features of the different CNs may be of value.

Distinct Challenges of Eruptive and Non-Eruptive Calcified Nodules in Percutaneous Coronary Intervention.

PURPOSE OF REVIEW: To provide a summary of prevalence, pathogenesis, and treatment of coronary calcified nodules (CNs). RECENT FINDINGS: CNs are most frequently detected at the sites of hinge motion of severely calcified lesions such as in the middle segment of right coronary artery and left main coronary bifurcation. On histopathology, CNs exhibit two distinctive morphologies: eruptive and non-eruptive. Eruptive CNs, which have a disrupted fibrous cap with adherent thrombi, are biologically active. Non-eruptive CNs, which have an intact fibrous cap without thrombi, are biologically inactive, representing either healed eruptive CNs or protrusion of calcium due to plaque progression. Recent studies using optical coherence tomography (OCT) have shown a difference in the mechanism of stent failure in the two subtypes, demonstrating early reappearance of eruptive CNs in the stent (at ~ 6 months) as a unique mechanism of stent failure that does not seem to be preventable by simply achieving adequate stent expansion. The cause of CN reappearance in stent is not known and could be due to acute or subacute intrusion or continued growth of the CN. Whether modification of CN is needed, the most effective calcium modification modality and effectiveness of stent implantation in eruptive CNs has not been elucidated. In this review, we discuss pathogenesis of CNs and how intravascular imaging can help diagnose and manage patients with CNs. We also discuss medical and transcatheter therapies beyond conventional stent implantation for effective treatment of eruptive CNs that warrant testing in prospective studies.

OCT-Guided vs Angiography-Guided Coronary Stent Implantation in Complex Lesions: An ILUMIEN IV Substudy.

BACKGROUND: ILUMIEN IV was the first large-scale, multicenter, randomized trial comparing optical coherence tomography (OCT)-guided vs angiography-guided stent implantation in patients with high-risk clinical characteristics and/or complex angiographic lesions. OBJECTIVES: The authors aimed to specifically examine outcomes in the complex angiographic lesions subgroup. METHODS: From the original trial population (N = 2,487), high-risk patients without complex angiographic lesions were excluded (n = 514). Complex angiographic lesion characteristics included: 1) long or multiple lesions with intended total stent length ≥28 mm; 2) bifurcation lesion with intended 2-stent strategy; 3) severely calcified lesion; 4) chronic total occlusion; or 5) in-stent restenosis. The study endpoints were: 1) final minimal stent area (MSA); 2) 2-year composite of serious major adverse cardiovascular events (MACEs) (cardiac death, target-vessel myocardial infarction [MI], or stent thrombosis); and 3) 2-year effectiveness, defined as target-vessel failure (TVF), a composite of cardiac death, target-vessel MI, or ischemia-driven target-vessel revascularization. RESULTS: The postpercutaneous coronary intervention (PCI) MSA was larger in the OCT-guided (n = 992) vs angiography-guided (n = 981) group (5.56 ± 1.95 mm2 vs 5.26 ± 1.81 mm2; difference, 0.30; 95% CI: 0.14-0.47; P < 0.001). Compared with angiography-guided PCI, OCT-guided PCI resulted in a lower risk of serious MACE (3.1% vs 4.9%; HR: 0.63; 95% CI: 0.40-0.99; P = 0.04). TVF was not significantly different between groups (7.3% vs 8.8%; HR: 0.82; 95% CI: 0.59-1.12; P = 0.20). CONCLUSIONS: In complex angiographic lesions, OCT-guided PCI led to a larger MSA and reduced the serious MACE, the composite of cardiac death, target-vessel MI, or stent thrombosis, compared with angiography-guided PCI at 2 years, but did not significantly improve TVF. (Optical Coherence Tomography Guided Coronary Stent Implantation Compared to Angiography: A Multicenter Randomized Trial in PCI; NCT03507777).

Influence of Pathophysiological Patterns of Coronary Artery Disease on Immediate Percutaneous Coronary Intervention Outcomes.

BACKGROUND: Diffuse coronary artery disease (CAD) impacts the safety and efficacy of percutaneous coronary intervention (PCI). Pathophysiological CAD patterns can be quantified using fractional flow reserve (FFR) pullbacks incorporating the pullback pressure gradient (PPG) calculation. This study aimed to establish the capacity of PPG to predict optimal revascularisation and procedural outcomes. METHODS: This prospective, investigator-initiated, single-arm, multicentre study enrolled patients with at least one epicardial lesion with an FFR ≤ 0.80 scheduled for PCI. Manual FFR pullbacks were employed to calculate PPG. The primary outcome of optimal revascularisation was defined as a post-PCI FFR ≥ 0.88. RESULTS: 993 patients with 1044 vessels were included. The mean FFR was 0.68 ± 0.12, PPG 0.62 ± 0.17, and post-PCI FFR 0.87 ± 0.07. PPG was significantly correlated with the change in FFR after PCI (r=0.65, 95% CI 0.61-0.69, p<0.001) and demonstrated excellent predicted capacity for optimal revascularisation (AUC 0.82, 95% CI 0.79-0.84, p<0.001). Conversely, FFR alone did not predict revascularisation outcomes (AUC 0.54, 95% CI 0.50-0.57). PPG influenced treatment decisions in 14% of patients, redirecting them from PCI to alternative treatment modalities. Periprocedural myocardial infarction occurred more frequently in patients with low PPG (<0.62) compared to those with focal disease (OR 1.71, 95% CI: 1.00-2.97). CONCLUSIONS: Pathophysiological CAD patterns distinctly affect the safety and effectiveness of PCI. The PPG showed an excellent predictive capacity for optimal revascularisation and demonstrated added value compared to a FFR measurement.

Harmonics management and hosting capacity enhancement: Optimal double-resistor damped double-tuned power filter with artificial hummingbird optimization.

This paper introduces a novel and improved double-resistor damped double-tuned passive power filter (DR-DDTF), designed using multi-objective optimization algorithms to mitigate harmonics and increase the hosting capacity of distribution systems with distributed energy resources. Although four different topologies of single-resistor damped double-tuned filters (DDTFs) have been studied before in the literature, the effectiveness of two different DR-DDTF configurations has not been examined. This work redresses this gap by demonstrating that via comprehensive simulations on two power systems, DR-DDTF provides better harmonic suppression and resonance mitigation than single-resistor alternatives. When it comes to optimizing the DR-DDTF for maximum hosting capacity and minimum system active power losses, the multi-objective artificial hummingbird outperformed six other algorithms in the benchmark. To allow for higher penetration of distributed generation without requiring grid upgrades, this newly developed harmonic mitigation filter provides a good alternative.