The state of the excimer laser for coronary intervention in the drug-eluting stent era

Drug-Eluting Balloons in Calcified Coronary Lesions: A Meta-Analysis of Clinical and Angiographic Outcomes

Background: The usefulness of drug-eluting balloons (DEBs) has not been fully elucidated in calcified coronary lesions (CCLs). This meta-analysis aimed to evaluate the efficacy of DEBs compared to a drug-eluting stent (DES) in this setting. Methods: PubMed, EMBASE and Cochrane were searched through December 2023. The primary endpoint was 12 months major adverse cardiac events (MACE). Secondary endpoints included clinical outcomes and angiographic results after PCI and at a 12-month follow-up. Results: Five studies and a total of 1141 patients with 1176 coronary lesions were included. Overall, the DEB was comparable to DES in MACE (RR = 0.86, 95% CI: 0.62-1.19, p = 0.36), cardiac death (RR = 0.59, 95% CI: 0.23-1.53, p = 0.28), myocardial infarction (RR = 0.89, 95% CI: 0.25-3.24, p = 0.87) and target lesion revascularization (RR = 1.1, 95% CI: 0.68-1.77, p = 0.70). Although the DEB was associated with worse acute angiographic outcomes (acute gain; MD = -0.65, 95% CI: -0.73, -0.56 and minimal lumen diameter; MD = -0.75, 95% CI: -0.89, -0.61), it showed better results at 12 months follow-up (late lumen loss; MD = -0.34, 95% CI: -0.62, -0.07). Conclusions: This meta-analysis showed that the DEB strategy is comparable to DES in the treatment of CCLs in terms of clinical outcomes. Although the DEB strategy had inferior acute angiographic results, it may offer better angiographic results at follow-up.

A novel approach to saline/contrast delivery in excimer laser coronary atherectomy (ELCA) to enhance efficacy: MAXCon ELCA technique

The advent of excimer laser coronary atherectomy (ELCA) nearly four decades ago heralded a novel way to treat complex lesions, both coronary and peripheral, which were previously untraversable and thus untreatable. These complex lesions include heavily calcified lesions, ostial lesions, bifurcation lesions, chronic total occlusions, in-stent restenosis (including stent underexpansion), and degenerative saphenous vein grafts. We discuss the technology of ELCA, its indications, applications, and complications, and suggest the "MAXCon ELCA" technique for better outcomes without increased risk. Lastly, we present a case of MAXCon ELCA effectively treating a complex lesion.

Intravascular lithotripsy for severe coronary calcification: a systematic review

INTRODUCTION

Coronary artery calcification remains a challenge in percutaneous coronary interventions, due to the higher risk of suboptimal result with subsequent poor clinical outcomes. Intravascular lithotripsy is a novel way of treating severe coronary calcification as it has the ability to modify calcium both circumferentially as well as transmurally, facilitating stent expansion and apposition. We conducted a systematic overview of the published literature on intravascular lithotripsy (IVL) assessing the efficacy and feasibility of IVL in treating severe coronary calcification.

EVIDENCE ACQUISITION

Of the retrieved publications, 62 met our inclusion criteria and were included. A total of 1389 patients (1414 lesions) with significant coronary calcification or under-expanded stents underwent IVL.

EVIDENCE SYNTHESIS

The mean age was 72.03 years (74.7% male). There was a significant improvement in acute and sustained vessel patency, with mean minimal lumen diameter of 2.78±0.46 mm, resulting in acute gain of 1.72±0.51 mm. The acute procedural success rate was 78.2 to 100% with in-hospital complication rate of 5.6 to 7.0%. The majority of the studies reported 30-day MACE, which was between 2.2 to 7.8%.

CONCLUSIONS

The recent studies have highlighted that the use of IVL with adjuvant intracoronary imaging has revolutionized the way of treating heavily calcified, non-dilatable coronary lesions and is likely to succeed the conventional ways of treating these complex lesions. We need further studies to gauge the long-term efficacy and safety of IVL against techniques currently available for calcium modification including conventional balloons, cutting or scoring balloons, rotational atherectomy and laser atherectomy.

Development of Biodegradable Polymeric Stents for the Treatment of Cardiovascular Diseases

Cardiovascular disease has become the leading cause of death. A vascular stent is an effective means for the treatment of cardiovascular diseases. In recent years, biodegradable polymeric vascular stents have been widely investigated by researchers because of its degradability and clinical application potential for cardiovascular disease treatment. Compared to non-biodegradable stents, these stents are designed to degrade after vascular healing, leaving regenerated healthy arteries. This article reviews and summarizes the recent advanced methods for fabricating biodegradable polymeric stents, including injection molding, weaving, 3D printing, and laser cutting. Besides, the functional modification of biodegradable polymeric stents is also introduced, including visualization, anti-thrombus, endothelialization, and anti-inflammation. In the end, the challenges and future perspectives of biodegradable polymeric stents were discussed.

Contemporary Evidence-Based Diagnosis and Management of Severe Coronary Artery Calcification

Percutaneous treatment of heavily calcified coronary lesions remains a challenge for interventional cardiologists with increased risk of incomplete lesion preparation, suboptimal stent deployment, procedural complications, and a higher rate of acute and late stent failure. Adequate lesion preparation through calcium modification is crucial in optimising procedural outcomes. Several calcium modification devices and techniques exist, with rotational atherectomy the predominant treatment for severely calcified lesions. Novel technologies such as intravascular lithotripsy are now available and show promise as a less technical and highly effective approach for calcium modification. Emerging evidence also emphasises the value of detailed characterisation of calcification severity and distribution especially with intracoronary imaging for appropriate device selection and individualised treatment strategy. This review aims to provide an overview of the non-invasive and invasive evaluation of coronary calcification, discuss calcium modification techniques and propose an algorithm for the management of calcified coronary lesions.

Contemporary tools and devices for coronary calcium modification

With the aging population, up to a third of patients referred for percutaneous coronary intervention (PCI) have moderate or severe calcified lesions assessed by coronary angiography. The presence of coronary calcium is associated with difficult device delivery, sub-optimal stent deployment, and prolonged procedures, with more complications. Furthermore, it is known that sub-optimal stent expansion is associated with poor clinical outcomes. In this manuscript we describe how to quantify the severity of coronary calcium, review the armamentarium of contemporary devices available for calcium modification, and provide a systematic approach to device selection, assessment of successful calcium modification, and stent optimization.

Review on Laser Technology in Intravascular Imaging and Treatment

Blood vessels are one of the most essential organs, which nourish all tissues in our body. Once there are intravascular plaques or vascular occlusion, other organs and circulatory systems will not work properly. Therefore, it is necessary to detect abnormal blood vessels by intravascular imaging technologies for subsequent vascular treatment. The emergence of lasers and fiber optics promotes the development of intravascular imaging and treatment. Laser imaging techniques can obtain deep vascular images owing to light scattering and absorption properties. Moreover, photothermal and photomechanical effects of laser make it possible to treat vascular diseases accurately. In this review, we present the research progress and applications of laser techniques in intravascular imaging and treatment. Firstly, we introduce intravascular optical coherent tomography and intravascular photoacoustic imaging, which can obtain various information of plaques. Multimodal intravascular imaging techniques provide more information about intravascular plaques, which have an essential influence on intravascular imaging. Secondly, two laser techniques including laser angioplasty and endovenous laser ablation are discussed for the treatment of arterial and venous diseases, respectively. Finally, the outlook of laser techniques in blood vessels, as well as the integration of laser imaging and treatment are prospected in the section of discussions.

Excimer Laser Coronary Angioplasty in Coronary Lesions: Use and Safety From the NCDR/CATH PCI Registry

[Figure: see text].

Laser for balloon uncrossable and undilatable chronic total occlusion interventions

BACKGROUND

There is limited information on use of laser in complex percutaneous coronary interventions (PCI). We examined the impact of laser on the outcomes of balloon uncrossable and balloon undilatable chronic total occlusion (CTO) PCI.

METHODS

We reviewed baseline clinical and angiographic characteristics and procedural outcomes of 4845 CTO PCIs performed between 2012 and 2020 at 32 centers.

RESULTS

Of the 4845 CTO lesions, 752 (15.5%) were balloon uncrossable (523 cases) or balloon undilatable (356 cases) and were included in this analysis. Mean patient age was 66.9 ± 10 years and 83% were men. Laser was used in 20.3% of the lesions. Compared with cases in which laser was not used, laser was more commonly used in longer length occlusions (33 [21, 50] vs. 25 [15, 40] mm, p = 0.0004) and in-stent restenotic lesions (41% vs. 20%, p < 0.0001). Laser use was associated with higher technical (91.5% vs. 83.1%, p = 0.010) and procedural (88.9% vs. 81.6%, p = 0.033) success rates and similar incidence of major adverse cardiac events (3.92% vs. 3.51%, p = 0.805). Laser use was associated with longer procedural (169 [109, 231] vs. 130 [87, 199], p < 0.0001) and fluoroscopy time (64 [40, 94] vs. 50 [31, 81], p = 0.003).

CONCLUSIONS

In a contemporary, multicenter registry balloon uncrossable and balloon undilatable lesions represented 15.5% of all CTO PCIs. Laser was used in approximately one-fifth of these cases and was associated with high technical and procedural success and similar major complication rates.

Contemporary use of excimer laser in percutaneous coronary intervention with indications, procedural characteristics, complications and outcomes in a university teaching hospital

Background

Excimer laser coronary atherectomy (ELCA) can be used as an adjunctive percutaneous coronary intervention treatment for challenging, heavily calcified lesions. Although previous studies have documented high rates of complication and restenosis, these predate the introduction of the smaller 0.9 mm laser catheter. As the coronary complexity has increased, there has been a renewed interest in the ELCA. This study investigates the indications, procedural characteristics, complications and outcomes of ELCA in a contemporary coronary interventional practice.

Methods

This single-centre study retrospectively analysed 50 patients treated with ELCA between January 2013 and January 2019.

Results

Patients had a mean age of 67.9±11.4 years with a male predominance (65.3%). 25 (50%) cases were performed in patients with stable angina. Failure to deliver the smallest available balloon/microcatheter was the most frequent indication in 32 (64%) cases for ELCA use. 30 (60%) of the procedures were performed via radial access. The 0.9 mm X-80 catheter was used in 41 (82%) of cases, delivering on average 9000±3929 pulses. ELCA-related complications included 2 coronary dissections and 1 perforation, all of which were covered with stents. No major complications could be directly attributed to the use of ELCA. There was one death and one case of stent thrombosis within 30 days of the procedure.

Conclusion

ELCA can be performed safely via the radial approach with a 0.9 mm catheter with a high success rate by suitably trained operators. The low procedure-related complications with contemporary techniques make this a very useful tool for complex coronary interventions, especially for difficult to dilate lesions and chronic total occlusion vessels.

Excimer Laser Atherectomy in Percutaneous Coronary Intervention: A Contemporary Review

Excimer laser coronary atherectomy (ELCA) during percutaneous coronary intervention (PCI) has been in use for more than twenty years. While early experiences were not favorable over balloon angioplasty alone, with improvement in operator technique, patient selection and technology, ELCA has established its own niche in contemporary PCI as a safe and effective atherectomy strategy. With growing experience in complex coronary interventions worldwide, ELCA has become one of the essential atherectomy tools offering unique advantages over other atherectomy devices. In the modern era, ELCA is commonly used for patients with in-stent restenosis, stent under expansion, balloon uncrossable lesions and chronic total occlusions. Technical success rates are reported to be >80% in most situations while procedural complication rates such as vessel dissection and perforation among others are reported to average 9% over the past 25 years with improvement over time. In this review, we provide a comprehensive systematic review of the ELCA system, its practical use, indications, and procedural techniques in the contemporary PCI era.

Treatment of In-Stent Restenosis Using Excimer Laser Coronary Atherectomy and Bioresorbable Vascular Scaffold Guided by Optical Coherence Tomography

The rate of in-stent restenosis (ISR) has become increasingly prevalent with the exponential growth in stent implantation due to an aging population and a higher life expectancy, in addition to the high rates of obesity and diabetes. In this prospective, single operator, all-comer study, we sought to analyze the performance of ELCA followed by bioresorbable vascular scaffold (BVS) placement in patients undergoing percutaneous coronary intervention (PCI) for ISR. A total of 13 patients had ISR treated with a combination of ELCA and BVS, with 9 patients having matched OCT pre, post ELCA and post BVS. Mean age was 65 ± 11.22 and 83% of the patients were male. Hypertension and dyslipidemia were present in 100% of the patients and smoking and diabetes in 50%. After the procedure, we did not detect residual stenosis over 10% in any patient, resulting in a technical success of 100%. No patients had MACE during their hospital stay or within the next six months, resulting in a procedure success of 100%. The mean lumen area increased 0.35 mm² from pre procedure to post ELCA and 3.58 mm² from post ELCA to post BVS. The final difference, from pre procedure to post BVS, was a 3.93 mm² lumen area gain. The mean lumen diameter increased 0.11 mm from baseline to ELCA, 0.95 mm from post laser to BVS implantation and 1.06 mm from pre procedure to post BVS. The NIH area reduced 0.48 mm² from pre to post ELCA, 1.13mm² from post ELCA to BVS implantation and 1.61 mm² from baseline to post BVS implantation. We conclude that ELCA is a safe and feasible debulking method to approach ISR, with high rates of post-procedural BVS success, within six months follow-up.

An application of RASER technique in the treatment of chronic total occlusion accompanied with stent fracture in right coronary artery: a case report

BACKGROUND

The interventional treatment of chronic total occlusion (CTO) with stent fracture as well as severe calcification was extremely difficult and no effective technique has been reported.

CASE PRESENTATION

A 50-year-old woman was hospitalized for angina, angiography revealed triple vessel disease, CTO accompanied with stent fracture in right coronary artery (RCA). Treatment using conventional coronary intervention was expected to be difficult. Therefore, we performed RASER technique, which was a combination of excimer laser coronary atherectomy (ELCA) with rotational atherectomy (RA), followed by the deployment of drug-eluting stents. Intravascular ultrasound (IVUS) revealed well attachment of the stents, the patient was discharged 3 days after the procedure and no recurrent chest discomfort was reported in a follow-up time of 10 months.

CONCLUSION

This case report provided a first report of RASER technique in the treatment of CTO with stent fracture and severe calcification.

Lesion Preparation with Orbital Atherectomy

Despite significant improvements in stent design, severe coronary calcification continues to impede adequate stent expansion and is associated with worse clinical outcomes. Angiography is limited in its ability to detect and comprehensively characterise calcified plaque. Intravascular imaging provides information on lesion morphology guiding appropriate treatment strategies. Orbital atherectomy allows for lesion preparation of severely calcified plaque prior to stent implantation. Utilising a unique mechanism of action incorporating centrifugal forces, a standard 1.25 mm eccentrically mounted and diamond-coated burr orbits bi-directionally to ablate calcified plaque. Lesion preparation with orbital atherectomy allows for modification of calcified plaque to facilitate stent expansion.

Contemporary Approach to Heavily Calcified Coronary Lesions

Percutaneous treatment of heavily calcified coronary lesions still represents a challenge for interventional cardiology, with higher risk of immediate complications, late failure due to stent underexpansion and malapposition, and consequently poor clinical outcome. Good characterisation of calcium distribution with multimodal imaging is important to improve the successful treatment of these lesions. The use of traditional or new dedicated devices for the treatment of calcified lesions allows better lesion preparation; therefore, it is important that we know the different mechanisms and technical features of these devices.

Comparison of 0.9-mm and 1.4-mm catheters in excimer laser coronary angioplasty for acute myocardial infarction

Excimer laser coronary angioplasty (ELCA) is a unique revascularization modality that can vaporize plaque and thrombus. Compared to thrombus aspiration therapy, ELCA is reported to provide better microcirculation and reduced peripheral embolism in treatment for acute coronary syndrome. Excimer laser catheters come in various sizes, and we sought to compare the 0.9- and 1.4-mm-diameter catheters. We retrospectively enrolled 90 acute myocardial infarction (AMI) patients who underwent primary percutaneous coronary intervention with excimer laser from August 2013 to March 2017 in our hospital. Patients were grouped by diameter of catheter that had been used, the 0.9 mm group (n = 51) and 1.4 mm group (n = 39). We evaluated myocardial perfusion, procedural success rate, short-term outcome, lesion crossability, and complications between the two groups. The percentage of patients whose final thrombolysis in myocardial infarction (TIMI) grade was 3 (0.9 mm 86.3% vs 1.4 mm 89.7% p = 0.75) and final myocardial blush grade (MBG) was 3 (0.9 mm 72.5% vs 1.4 mm 69.2% p = 0.82) was similarly high for both groups. Procedural success rate, in-hospital major adverse cardiac events (MACE), lesion crossability, and complications were also similar. This study showed that efficacy of 0.9 and 1.4 mm excimer laser catheter was equivalent in ELCA for AMI patients. If one takes into account lesion crossability, debulking effects, and the stunned platelets phenomenon, the 0.9 mm excimer laser catheter is sufficient for ELCA in AMI patients.

How Should We Treat Heavily Calcified Coronary Artery Disease in Contemporary Practice? From Atherectomy to Intravascular Lithotripsy

Heavily calcified and densely fibrotic coronary lesions continue to represent a challenge for percutaneous coronary intervention (PCI), as they are difficult to dilate, and it is difficult to deliver and implant drug-eluting stents (DES) properly. Poor stent deployment is associated with high rates of periprocedural complications and suboptimal long-term clinical outcomes. Thanks to the introduction of several adjunctive PCI tools, like cutting and scoring balloons, atherectomy devices, and to the novel intravascular lithotripsy technology, the treatment of such lesions has become increasingly feasible, predictable and safe. A step-wise progression of strategies is described for coronary plaque modification, from well-recognised techniques to techniques that should only be considered when standard manoeuvres have proven unsuccessful. We highlight these techniques in the setting of clinical examples how best to apply them through better patient and lesion selection, with the main objective of optimising DES delivery and implantation, and subsequent improved outcomes.

Challenges With Severe Coronary Artery Calcification in Percutaneous Coronary Intervention: A Narrative Review of Therapeutic Options

Coronary calcification often complicates atherosclerosis. With an aging population, coinciding with lower thresholds for coronary angiography and percutaneous coronary intervention (PCI), severe calcific coronary stenoses remain a challenge for interventional cardiologists. Although advances in coronary guidewires, percutaneous balloons, and adjunctive procedural devices have improved success of PCI, recalcitrant calcified lesions not amenable to the conventional technique frequently occur. Coronary atherectomy with plaque modification provides a therapeutic alternative. As such, various modalities such as rotational, orbital or laser atherectomy, and more recently shockwave lithoplasty have become therapeutic options for PCI. We provide a summary of the principles, technique, and contemporary evidence for these currently approved devices designed to treat severe coronary calcific lesions.

Utility of adjunctive modalities in Coronary chronic total occlusion intervention

Coronary chronic total occlusion (CTO) intervention remains one of the most challenging domains in interventional cardiology. Due to the technical challenges involved and potential procedural complications, CTO percutaneous coronary intervention (PCI) attempt and success rates remain less than standard PCI. However, the use of several adjunctive tools such as intravascular ultrasound, optical coherence tomography, rotational atherectomy, orbital atherectomy, excimer laser coronary atherectomy and percutaneous left ventricular assist device may contribute to improved CTO PCI success rates or provide better hemodynamic assessment of CTO lesion (i.e., using fractional flow reserve). In this review we present the current literature describing the utility and efficacy of these adjunctive modalities in CTO intervention.

Atherectomy Devices for the Treatment of Calcified Coronary Lesions

The presence of moderate and severe coronary artery calcification (CAC) is associated with higher rates of angiographic complications during percutaneous coronary intervention (PCI), as well as higher major adverse cardiac events compared with noncalcified lesions. Diabetes mellitus, a risk factor for CAC, is increasing in the United States. Vessel preparation before PCI with atherectomy can facilitate successful stent delivery and expansion that may otherwise not be possible. We review here CAC prevalence, risk factors, and impact on PCI, as well as the currently available coronary atherectomy devices including rotational atherectomy, orbital atherectomy, and laser atherectomy.

Treatment of calcified coronary artery lesions

Heavily calcified coronary plaques represent a complex lesion subset and a challenge to the interventional cardiologist, as they are often resistant to simple plaque modification with conventional balloon angioplasty. Inadequate plaque modification can lead to stent underdeployment, which itself predisposes to in-stent restenosis and stent thrombosis. Over the years, a number of mechanical devices ranging from modified angioplasty balloons to atherectomy devices have become available in order to tackle such lesions. Here we review these devices concentrating on the evidence behind their use.

Current understanding of coronary artery calcification

Coronary artery calcification (CAC) is highly prevalent in patients with coronary heart disease (CHD) and is associated with major adverse cardiovascular events. There are two recognized type of CAC—intimal and medial calcification, and each of them have specific risk factors. Several theories about the mechanism of vascular calcification have been put forward, and we currently believe that vascular calcification is an active, regulated process. CAC can usually be found in patients with severe CHD, and this asymptomatic phenomenon make early diagnosis of CAC important. Coronary computed tomographic angiography is the main noninvasive tool to detect calcified lesions. Measurement of coronary artery calcification by scoring is a reasonable metric for cardiovascular risk assessment in asymptomatic adults at intermediate risk. To date, effective medical treatment of CAC has not been identified. Several strategies of percutaneous coronary intervention have been applied to CHD patients with CAC, but with unsatisfactory results. Prognosis of CAC is still a major problem of CHD patients. Thus, more details about the mechanisms of CAC need to be elucidated in order to improve the understanding and treatment of CAC.