Contribution of localized calcium deposits to dissection after angioplasty. An observational study using intravascular ultrasound

Kidney disease, diabetes, and diameter stenosis predict Rotablation bailout in modified balloon application for severely calcified coronary lesions

BACKGROUND

Modified balloon (MB) treatment in severely calcified coronary artery lesions is an established technique. However, some lesions require Rotablation (RA) as bailout strategy.

AIMS

This study aimed to assess predictors of switch from MB to RA and its impact on procedural and midterm outcomes.

METHODS

Four hundred and eighty-three consecutive patients were included undergoing MB treatment (n = 204) with a scoring or cutting balloon, or upfront RA treatment (n = 279) serving as control cohort. Strategy switch from MB to RA was performed in 19 of 204 patients. Procedural success was defined as successful stent implantation and TIMI III flow.

RESULTS

In the MB cohort, median age was 72 [63-78] years, 75.5% were male and 42.1% had acute coronary syndrome. Procedure success was achieved in 89.4% of the switch group versus 98.4% of the MB only group (p < 0.001) and in 96.4% of the RA cohort. In the switch group, periprocedural complications (31.6% vs. 8.1% vs. 11.8%, p = 0.007), radiation dose (149 [126-252] vs. 59 [30-97] vs. 102 [59-156] Gcm2; p < 0.001) and contrast volume (250 [190-250] vs. 190 [150-250] vs. 195 [190--250] mL; p < 0.001) were significantly higher. Diabetes (OR 3.8, 95% CI 1.1-13.9, p = 0.042), chronic kidney disease stage 4 or 5 (OR 19.0, 95% CI 3.3-108.6, p < 0.001) and pronounced calcification resulting in higher angiographic diameter stenosis (OR 1.13, 95% CI 1.1-1.2, p = 0.001) independently predicted strategy switch. Midterm results were not affected by strategy switch regarding 1-year target lesion revascularization rates (86% vs. 89% vs. 89%; log-rank p = 0.95).

CONCLUSION

Primary RA strategy might be considered in patients with severely calcified coronary artery lesions with high angiographic diameter stenosis, diabetes or impaired renal function due to increased periprocedural complication rates, radiation dose, and contrast volume following strategy switch.

Influence of a Novel Morphology-Driven Classification on Limb Salvage after Isolated Tibial Intervention for Chronic Limb Threatening Ischemia

BACKGROUND

Infra-popliteal interventions for chronic limb-threatening ischemia (CLTI) can be impacted by the morphology of the tibial vessels. The aim of this study was to examine the impact of a novel morphology-driven classification on the outcomes of isolated tibial intervention for CLTI.

METHODS

A database of patients undergoing isolated tibial interventions for CLTI at a single center between 2010 and 2020 was retrospectively queried. Patients with isolated infra-popliteal disease were identified, and their anatomy was scored as present or absent for lesion calcification (1 point), target vessel diameter<3.0 mm (1 point), lesion length>300 mm (1 point), and poor pedal runoff score (1 point). Patients were then divided into 3 groups: low risk (0 or 1 points), moderate risk (2 points), and high risk (3 or 4 points). Intention to treat analysis by the patient was performed. Limb-based patency (the absence of reintervention, occlusion, critical stenosis [>70%], or hemodynamic compromise with ongoing symptoms of CLTI as it related to the patency of the preoperatively determined target artery pathway) was assessed. Patient-oriented outcomes of amputation-free survival (AFS; survival without major amputation) and freedom from major adverse limb events (MALE; above ankle amputation of the index limb or major reintervention: new bypass graft, jump/interposition graft revision) were evaluated.

RESULTS

1,607 patients (55% male, average age 60 years, 3,846 vessels) underwent tibial intervention for CLTI. The majority of the patients were diabetic and of Hispanic origin. Morphologically, 27%, 31%, and 42% of the vessels were categorized as low risk, moderate risk, and high risk, respectively. There was a significant worsening of the infra-popliteal Global Limb Anatomic Staging System (GLASS) grading as the morphological risk increased. The 30-day major adverse cardiac events (MACE) were equivalent across the groups and were under the stated objective performance goal (OPG) of ≤10%. In contrast, both the 30-day MALE and the 30-day major amputations were significantly different across the groups, with the low-risk group remaining under the OPG of ≤9% and ≤4%, respectively, while the moderate risk and high risk exceeded the goal threshold. For the OPG, freedom from MALE was 60 ± 5%, 46 ± 5%, and 22 ± 9% at 5 years for low-, moderate-, and high-risk groups, respectively (mean ± standard error of the mean; P = 0.008). Overall AFS was 55 ± 5%, 37 ± 6%, and 18 ± 7% at 5 years for low-, moderate-, and high-risk groups, respectively (mean ± standard error of the mean; P = 0.003).

CONCLUSIONS

Tibial anatomic morphology impacts isolated tibial endovascular intervention with adverse morphology associated with poorer short- and long-term outcomes. Risk stratification based on anatomic predictors should be an additional consideration as one intervenes on infra-popliteal vessels for CLTI.

Dedicated Balloon Techniques for Coronary Calcium Modification

Coronary calcification represents a significant technical challenge in percutaneous coronary intervention and is associated with worse clinical outcomes. Fortunately, a number of balloon-assisted technologies are available to aid in the management of coronary calcification before stenting. Adequate lesion preparation is crucial in the successful management of calcified coronary lesions. Balloon-based techniques can be a safe and effective method of lesion preparation and, as such, are an integral part of an interventionalist's armamentarium. In this mini-review, we focus on the use of non-compliant balloons, super high-pressure non-compliant balloons, cutting balloons, scoring balloons and intravascular lithotripsy.

The impact of novel scoring balloon and cutting balloon after orbital atherectomy on severely calcified coronary lesion as assessed by optical coherence tomography

BACKGROUND

Debulking devices are often followed by a scoring or cutting balloon in percutaneous coronary intervention (PCI) for severely calcified lesions. However, there are limited data on balloon preparation after orbital atherectomy (OA) assessed using optical coherence tomography (OCT).

AIM

We aimed to compare the effects of a novel scoring and cutting balloon on calcified coronary lesions with OCT.

METHODS

We retrospectively examined 38 patients (38 lesions) who underwent PCI with a scoring or a cutting balloon after OA. All patients underwent pre-PCI, preballooning, postballooning, and post-PCI OCT imaging. We divided the patients into novel scoring-balloon (group A: n = 22) and cutting-balloon (group B: n = 16) groups and compared the OCT findings, including minimum lumen area (MLA) and expansion ratio (MLA divided by mean reference lumen area).

RESULTS

The mean patient age was 76.1 ± 8.7 years; 71.5% were male. There were no significant differences in patient background between both groups. Regarding procedural characteristics, the maximum balloon pressure was significantly higher in group A (median 23 atm, interquartile range [IQR] 18-24 vs. 12 atm [IQR: 10-12], p < 0.01). Although a calcium score of 4 was more frequently observed in group A (86.4% vs. 62.5%, p = 0.12), post-PCI MLA was comparable between both groups (3.95 mm2 [IQR: 3.27-4.41] vs. 3.43 mm2 [IQR: 2.90-4.82], p = 0.63). Furthermore, the expansion ratio was significantly greater in group A (0.83 ± 0.20 vs. 0.68 ± 0.14, p < 0.01).

CONCLUSION

Despite a higher calcium score, a larger expansion ratio was achieved in patients with a novel scoring balloon than in those with a cutting balloon after OA.

Prevalence and anatomical factors associated with stent under-expansion in non-severely calcified lesions

BACKGROUND

Stent underexpansion, typically related to lesion calcification, is the strongest predictor of adverse events after percutaneous coronary intervention (PCI). Although uncommon, underexpansion may also occur in non-severely calcified lesions.

AIM

We sought to identify the prevalence and anatomical characteristics of underexpansion in non-severely calcified lesions.

METHODS

We included 993 patients who underwent optical coherence tomography-guided PCI of 1051 de novo lesions with maximum calcium arc <180°. Negative remodeling (NR) was the smallest lesion site external elastic lamina diameter that was also smaller than the distal reference. Stent expansion was evaluated using a linear regression model accounting for vessel tapering; underexpansion required both stent expansion <70% and stent area <4.5mm2.

RESULTS

Underexpansion was observed in 3.6% of non-heavily calcified lesions (38/1051). Pre-stent maximum calcium arc and thickness were greater in lesions with versus without underexpansion (median 119° vs. 85°, p = 0.002; median 0.95 mm vs. 0.78 mm, p = 0.008). NR was also more common in lesions with underexpansion (44.7% vs. 24.5%, p = 0.007). In the multivariable logistic regression model, larger and thicker eccentric calcium, mid left anterior descending artery (LAD) location, and NR were associated with underexpansion in non-severely calcified lesions. The rate of underexpansion was especially high (30.7%) in lesions exhibiting all three morphologies. Two-year TLF tended to be higher in underexpanded versus non-underexpanded stents (9.7% vs. 3.7%, unadjusted hazard ratio [95% confidence interval] = 3.02 [0.92, 9.58], p = 0.06).

CONCLUSION

Although underexpansion in the absence of severe calcium (<180°) is uncommon, mid-LAD lesions with NR and large and thick eccentric calcium were associated with underexpansion.

Arterial dissection during peripheral vascular interventions

OBJECTIVE

Arterial dissection (AD) is a known complication of peripheral vascular interventions (PVIs), but its incidence and significance have not been well-characterized. This study examines AD in the Vascular Quality Initiative database for patients treated for peripheral arterial disease. Our hypothesis is that AD is associated with decreased patency and worse limb outcomes.

METHODS

The Vascular Quality Initiative PVI registry (2016-2021) was reviewed. Patients were divided based on the presence or absence of reported AD during the procedure. Trend of incidence and management of AD was derived. The characteristics and outcomes of patients with and without AD were compared. The primary endpoint was primary patency.

RESULTS

There was a total of 177,790 cases, and 3% had AD. The incidence of AD significantly increased over the study period from 2.4% to 3.6% (P = .007). Endovascular therapy was used to treat AD in 83.7% of cases, 14.5% were treated medically, and only 1.8% required open surgery. Patients with AD were significantly more likely to be female (47.4% vs 39.7%; P < .001). Patient with AD were more likely to have a history of smoking (79.7% vs 77.2%; P < .001), but were significantly less likely to be on dialysis (8.2% vs 9.3%; P < .001) compared with patients without AD. Patients with AD were more likely to have femoropopliteal disease (45.2% vs 38.0%; P < .001) and undergo treatment of more complex disease as denoted by higher mean number of lesions treated (1.95 ± 1.01 vs 1.71 ± 0.89; P < .001), longer occlusion length (8 ± 16 vs 7 ± 15 cm; P < .001), and more severe TransAtlantic Inter-Society Consensus grade (Grade D: 36.2% vs 29.1%; P < .001). The proportion of stenting as a treatment modality was higher in the dissection group (55.4% vs 41.1%; P < .001). After a mean follow-up of 828 days, patients with AD had significantly lower primary patency than patients without AD. Kaplan-Meier curves demonstrated that the AD group had lower primary patency (86.9% vs 91%; P < .001) and reintervention-free survival (79.5 % vs 84.1%; P < .001) at 1 year with difference in amputation-free survival. Cox proportional hazard regression confirmed the independent association of AD with primary patency and reintervention-free survival.

CONCLUSIONS

AD is more common in women and is more likely to occur during treatment of the femoropopliteal segment. AD is associated with decreased primary patency and reintervention-free survival after PVI for peripheral arterial disease.

Sex-specific analysis of intravascular lithotripsy for peripheral artery disease from the Disrupt PAD III observational study

OBJECTIVE

Endovascular therapy of lower extremity peripheral artery disease (PAD) is associated with higher complication rates and worse outcomes in women vs men. Although intravascular lithotripsy (IVL) has shown similarly favorable outcomes in men and women in calcified coronary arteries, there is no published safety and effectiveness data of peripheral IVL differentiated by sex. This study aims to evaluate sex-specific acute procedural safety and effectiveness following IVL treatment of calcified PAD.

METHODS

We performed a secondary analysis of the multicenter Disrupt PAD III Observational Study, which assessed short-term procedural outcomes of patients undergoing treatment of symptomatic calcified lower extremity PAD with the Shockwave peripheral IVL system. Adjudicated acute safety and efficacy outcomes were compared by sex using univariate analysis performed with the χ2 test or Fisher exact test, as appropriate.

RESULTS

A total of 1262 patients (29.9% women) were included, with >85% having moderate to severe lesion calcification. Women were older (74 vs 71 years; P < .001), had lower ankle-brachial index (0.7 vs 0.8; P = .003), smaller reference vessel size (5.3 vs 5.6 mm; P = .009), and more severe stenosis at baseline vs men (82.3% vs 79.8%; P = .012). Rates of diabetes, renal insufficiency, chronic limb-threatening ischemia, lesion length, and atherectomy use were similar in both groups. Residual stenosis after IVL alone was significantly reduced in both groups. Final residual stenosis was 21.9% in women and 24.7% in men (P = .001). Serious angiographic complications were infrequent and similar in both groups (1.4% vs 0.6%; P = .21), with no abrupt vessel closure, distal embolization, or thrombotic events during any procedure.

CONCLUSIONS

The use of IVL to treat calcified PAD in this observational registry demonstrated favorable acute safety and effectiveness in both women and men.

Intravascular laser lithotripsy for calcium fracture in human coronary arteries

BACKGROUND

Electrical intravascular lithotripsy (E-IVL) uses shock waves to fracture calcified plaque.

AIMS

We aimed to demonstrate the ability of laser IVL (L-IVL) to fracture calcified plaques in ex vivo human coronary arteries and to identify and evaluate the mechanisms for increased vessel compliance.

METHODS

Shock waves were generated by a Ho:YAG (Holmium: yttrium-aluminium-garnet) laser (2 J, 5 Hz) and recorded by a high-speed camera and pressure sensor. Tests were conducted on phantoms and 19 fresh human coronary arteries. Before and after L-IVL, arterial compliance and optical coherence tomography (OCT) pullbacks were recorded, followed by histology. Additionally, microcomputed tomography (micro-CT) and scanning electron microscopy (SEM) were performed. Finite element models (FEM) were utilised to examine the mechanism of L-IVL.

RESULTS

Phantom cracks were obtained using 230 μm and 400 μm fibres with shock-wave pressures of 84±5.0 atm and 62±0.4 atm, respectively. Post-lithotripsy, calcium plaque modifications, including fractures and debonding, were identified by OCT in 78% of the ex vivo calcified arteries (n=19). Histological analysis revealed calcium microfractures (38.7±10.4 μm width) in 57% of the arteries which were not visible by OCT. Calcium microfractures were verified by micro-CT and SEM. The lumen area increased from 2.9±0.4 to 4.3±0.8 mm2 (p<0.01). Arterial compliance increased by 2.3±0.6 atm/ml (p<0.05). FEM simulations suggest that debonding and intimal tears are additional mechanisms for increased arterial compliance.

CONCLUSIONS

L-IVL has the capability to increase calcified coronary artery compliance by multiple mechanisms.

Iatrogenic coronary dissection: state of the art management

Iatrogenic coronary artery dissections (ICAD) are rare but potentially devastating complications during coronary angiography and percutaneous coronary interventions (PCI). Intima media complex separation may be produced either by the catheter tip or during PCI. Patient characteristics and procedure related risk factors are intimately linked to catheter induced ICAD over diagnostic angiography. Moreover, the increasing complexity of patients undergoing PCI, which frequently involves treatment of heavily calcified or occluded vessels, has increased the likelihood of dissections during PCI. A prompt recognition, along with a prompt management (either percutaneous, surgical or even careful watching), are key in preventing catastrophic consequences of ICAD, such as left ventricular dysfunction, cardiogenic shock, periprocedural myocardial infarction (MI) or cardiac death. This review aims to summarize the main updates concerning the pathophysiology, highlight key risk factors and suggest recommendations in management and treatment of ICAD.

Comparative Analysis of Mortality and Amputation Rates in Patients Undergoing Atherectomy for Infra-Popliteal Peripheral Arterial Disease: Insight From the VQI

INTRODUCTION

Infra-popliteal peripheral arterial disease (IPPAD) poses challenges due to high restenosis and occlusion rates. The BASIL-2 trial demonstrated the superiority of endovascular treatment compared with surgical bypass in patients with IPPAD. However, the association between different endovascular modalities and clinical outcomes has not been conclusive.

HYPOTHESIS

Combining plain old balloon angioplasty (POBA) with atherectomy is associated with improved clinical outcomes compared with POBA alone.

METHODS

Patients who underwent POBA vs POBA+atherectomy for IPPAD from the Vascular Quality Initiative database were identified. To mitigate potential selection bias, we employed propensity score matching (PSM) to balance the distribution of confounding variables for mortality identified on multivariable logistic regression. Subsequently, we compared patient characteristics and long-term outcomes between the 2 treatment groups.

RESULTS

Among patients who underwent endovascular intervention for IPPAD, 19 979 individuals (80.8%) were treated with POBA alone, while 4747 (19.2%) were treated with both POBA+atherectomy after PSM. Propensity score matching ensured minimal differences in baseline characteristics, such as indication for lower extremity revascularization (LER) and history of LER. After PSM, patients receiving POBA+atherectomy experienced higher rates of technical success and lower perioperative complications, such as renal complications and hematoma, compared with POBA alone. During long-term follow-up, patients who underwent atherectomy had lower rates of major amputation and major adverse limb events (MALE) but slightly lower freedom from reintervention. Nonetheless, there were no differences in mortality.

CONCLUSION

Combining POBA with atherectomy appears to be a safe approach in patients with IPPAD, with lower rates of long-term amputation and MALE at the cost of a higher risk of reintervention.

CLINICAL IMPACT

The use of adjunctive atherectomy is associated with improved long-term outcomes in patients with infra-popliteal disease.

Safety and Effectiveness of Excimer Laser Ablation Combined With Drug-Coated Balloon for Atherosclerotic Obliterans in the Lower Extremity

PURPOSE

To evaluate the safety and effectiveness of excimer laser ablation (ELA) combined with drug-coated balloon (DCB) for atherosclerotic obliterans (ASO) of the lower extremities.

MATERIALS AND METHODS

From June 2019 to December 2020, all eligible patients were enrolled. Demographics, characteristics of lesions, complications, and follow-up information were collected and analyzed. The primary endpoint was major amputation-free survival (MAFS). Secondary endpoints included technical success, primary patency, bailout stent, distal embolization, target lesion reintervention (TLR), and ulcer healing rate. Major amputation-free survival and primary patency were calculated by Kaplan-Meier analysis.

RESULTS

A total of 71 patients were enrolled. Forty-eight (81.7%) patients presented critical limb ischemia (CLI) and 48.6% of them was calcification class 4 according to Peripheral Arterial Calcium Scoring System (PACSS). Chronic totally occluded (CTO) disease was the most common lesion in 66.0% of them and superficial femoral artery (SFA) was the most common segment in 59.6%. Technical success rate was 93.0%. One-year follow-up was finished in 25 (35.2%) patients. The primary patency and MAFS were 92.0%±27.6% and 96.0%±20.0% at 12 months, respectively. During the mean follow-up of 9.4±4.3 months, clinically-driven TLR occurred in 2 (2.8%) patients, and major and minor amputation occurred in 2 (2.8%) and 1 (1.4%) patient, respectively.

CONCLUSION

The early results demonstrated that ELA was an effective treatment in de novo, in-stent restenosis (ISR) and CTO lesions. Meanwhile, ELA could prepare the lumen for the use of DCB and reduce the implantation of stents, especially in segments unsuitable for stenting. Mid-term and long-term results need to be awaited.

Insights From the FDA's MAUDE Database Regarding the Real-World Safety of Jetstream Atherectomy for Peripheral Arterial Disease

INTRODUCTION

Rotational atherectomy has shown promise as an adjunctive therapy to percutaneous transluminal angioplasty (PTA) and stenting for the treatment of peripheral arterial disease (PAD). However, published data regarding the safety of these devices are limited. The Food and Drug Administration Manufacturer and User Facility Device Experience (MAUDE) database collects reports of adverse event for medical devices. We present 3 years of MAUDE adverse events data for the Jetstream Atherectomy System (Boston Scientific) for the treatment of PAD.

MATERIALS AND METHODS

We searched MAUDE from January 1, 2019 to December 31, 2021. Duplicate reports and those with insufficient information were excluded, leaving a total of 500 reports for analysis. Adverse events were categorized as either patient complication, device malfunction, or both. Adverse events were classified using the Cardiovascular and Interventional Radiological Society of Europe's (CIRSE) classification system for adverse events.

RESULTS

The most common patient complications were embolism (22; 4.4%), dissection (17; 3.4%), vessel perforation (12; 2.4%), and device fracture in the patient (6; 1.2%). The most common modes of device failure were entrapment of the device on the guidewire (134; 27%), loss of blade rotation (116; 23%), loss of aspiration (99; 20%), and mechanical damage (57; 11%). As per the CIRSE adverse events classification, most events had no post-procedural sequelae (475; 95%), followed by those requiring prolonged observation (14; 2.8%), and post-procedural therapy without long-term sequelae (10; 2.0%). One hundred six devices (21%) were returned for manufacturer analysis.

CONCLUSION

We highlight important adverse events encountered in real-world practice with the Jetstream Atherectomy System. This analysis provides further understanding of the safety profile and modes of failure of Jetstream, and could help guide improvements in product design and manufacturer-user training. There is greater need for root-cause analysis that can aided by returning devices to the manufacturer.

CLINICAL IMPACT

We highlight important adverse events encountered in real-world practice with the Jetstream Atherectomy System. The MAUDE database is useful for capturing and characterizing modes of device failure/malfunction not typically described in conventional clinical studies. This may provide valuable information to help guide improvements in product design and manufacturer-user training. This information could also potentially be useful in helping establish manufacturer and product liability in the setting of medicolegal claims. We hope that by contributing to the growing understanding of the safety profile of the Jetstream Atherectomy System, our study may help physicians and patients come to more informed decisions regarding treatment options for PAD.

Carotid artery dissections from transcarotid artery revascularization as reported by the Food and Drug Administration

OBJECTIVES

Transcarotid artery revascularization (TCAR) is a hybrid procedure that allows reversal of blood flow away from the brain while placing a stent through direct surgical access of the common carotid artery. It has been shown to have a lower risk of perioperative stroke compared with any prospective trial of transfemoral carotid artery stenting. However, intraoperative injuries related to the procedure and its management are not well characterized. One of the intraoperative complications seen in TCAR is iatrogenic carotid artery dissection (CD). We aim to add qualitative insight in further characterizing CDs and its management in this emerging technology.

METHODS

The Food and Drug Administration (FDA) maintains the Manufacturer and User Facility Device Experience (MAUDE) database for surveillance of all medical devices approved for use. This database was queried for all cases associated with Silk Road Medical's ENROUTE Transcarotid Neuroprotection System from September 2016 to October 2020. Case narratives related to CD were individually analyzed to determine time of injury (intraoperative, recovery, and post-discharge follow-up). CD reporting was further analyzed for the associated procedural event at the time of injury, number of access attempts to CD repair, and type of CD repair. Reports associated with CD repair were further categorized into endovascular repair and open surgical repair.

RESULTS

Of the 115 unique adverse events in the database, there were 58 CDs. Most were identified intraoperatively (n = 55), while three were incidentally found postoperatively. Overall, sheath placement was the most common procedural event attributed to CD (N = 34). There was adequate narrative information about CD repair in 54 patients. Intraoperative repair was performed in 52 cases and two were repaired after post-discharge follow-up imaging was performed.Among CDs that did not require additional access to engage the true lumen, the proportion of endovascular repair (62.5%) was significantly higher (p = .044) compared to the proportion of open surgical repair (37.5%). However, the proportion of open surgical repair (75%) was significantly higher than the proportion of endovascular repair (25%) in CDs with persistent failure to engage the true lumen despite ≥2 access attempts (p = .039).

CONCLUSION

CD is the most common injury related to TCAR as reported on MAUDE. The most commonly reported procedural event associated with CD was sheath placement. The rate of intraoperative endovascular and open surgical CD repair was associated with whether the access to the true lumen of the carotid artery required additional access attempts or not. This should add qualitative insight among the vascular surgery community regarding intraoperative management of CDs from a TCAR procedure.

Objective Evaluation With Noncontrast Computed Tomography Can Reveal Calcified Plaque Solidity in Peripheral Artery Diseases

PURPOSE

The presence of severely calcified plaque remains problematic in endovascular therapy, and no specific endovascular treatment strategy has been established. Estimating plaque solidity before the procedure may help operators penetrate calcified plaque with a guide wire. The aim of this study was to establish a method of measuring plaque solidity with noncontrast computed tomography (CT).

METHODS

This retrospective, single-center study included consecutive patients who, between October 2020 and July 2022, underwent noncontrast 5 mm and 1 mm CTs before endovascular therapy to penetrate calcified plaque with a wire in the common femoral, superficial femoral, and popliteal arteries. Three cross-sectional CT slices were selected. To target a calcified plaque lesion, the operator identified a region of interest, which corresponded to 24×24 pixels, and Hounsfield unit (HU) values of each pixel were displayed on the CT image. The average HU values and the ratio of number of pixels of lower values (130-599 HU) represented plaque solidity. We used the Mann-Whitney-Wilcoxon rank-sum test and the chi-square test to compare the solidity of plaques penetrated and not penetrated by the wire.

RESULTS

We evaluated 108 images of 36 calcified plaque lesions (in 19 patients). The wire penetrated 28 lesions (77.8%) successfully. The average HU value was significantly lower in the lesions that the wire penetrated than in the others, in both the 5 mm CT slices (434.7±86.8 HU vs 554.3±112.7 HU, p=0.0174) and 1 mm slices (497.8±103.1 HU vs 593.5±114.5 HU, p=0.0381). The receiver operating curve revealed that 529.9 and 533.9 HU in the 5 and 1 mm slices, respectively, were the highest values at which wires could penetrate. Moreover, at the lesions that were penetrates successfully, the ratio of number of lower HU value pixels was significantly higher both in 5 mm slice CTs (74.7±13.4 vs 61.7±13.1%, p=0.0347) and 1 mm (68.7±11.8 vs 57.1±11.4%, p=0.0174).

CONCLUSION

The use of noncontrast CT to evaluate plaque solidity was associated with successful wire penetration of calcified lesions in peripheral arteries.

CLINICAL IMPACT

This study revealed an association between the wire penetration inside calcified plaque and plaque solidity estimated using non-contrasted computed tomography. The mean Hounsfield unit values of three cross-sections in calcified plaques were associated with the successful wire penetration. This wire penetration difficulty is associated with extended procedure time, excessive radiation exposure, usage of extra contrast agents, and increased medical costs. Therefore, estimating calcified plaque solidity before procedure enables us to choose effective and lean procedures. In addition, to predict the success of dilating calcified plaque from the inside is also beneficial when the operator wants to avoid extra scaffold implantation for target lesions.

Intravascular Lithotripsy in Calcified Peripheral Lesions: Single-Center JEN-Experience

Peripheral artery disease (PAD) shows increasing need for revascularization therapy. Interventional success in calcified lesions is limited. Here, intravascular lithotripsy (IVL), modifying intimal and medial calcium, is a promising treatment approach. A single-center, prospective all-comers registry for patients undergoing peripheral IVL was established to examine treatment success in PAD with severe vessel calcification. Periprocedural safety events as well as short-term and intermediate follow-up clinical data were evaluated. Between December 2018 and January 2021 all consecutive patients receiving peripheral lithotripsy at our center were analyzed. Clinical and angiographic data were evaluated. Angiographic images were analyzed using a semiautomatic software for quantitative vessel analysis. Eighty-five lesions in 61 limbs were treated with IVL in 51 patients presenting with Rutherford classes 2 to 5. Most lesions (68%) were localized in the superficial femoral artery. Mean calcified lesion length was 102.5 mm (10-390 mm), with a median peripheral arterial calcium score of 3, indicating a highly calcified status. In 58% of the patients, IVL was used as a stand-alone therapy. IVL resulted in a mean acute luminal gain of 2.6 ± 0.9 mm, resulting in stenosis reduction by 42.1 ± 15%. Mean ankle brachial index (ABI) improved significantly from 0.6 to 0.8 ( p  < 0.0001) on day 1 after the intervention and remained stable at 6 months. This large real-world data of peripheral IVL reports compelling safety in a complex patient cohort. For the first time, clinical follow-up data demonstrated a sustained significant improvement in ABI after 6 months.

Electroplating a miniature diamond wheel for grinding of the calcified plaque inside arteries

A miniature grinding wheel (0.85 mm diameter) was fabricated by nickel (Ni)-diamond electroplating on a thin (0.65 mm outer diameter) flexible hollow stainless steel drive shaft to remove the calcified plaque in coronary and peripheral arteries by atherectomy procedure. To coat electrically nonconductive diamond grits, the drive shaft was submerged in a pile of diamond grit during Ni electroplating. The electroplating current density and temperature were investigated for better surface finishing and Faraday efficiency. The electroplating time to obtain the designed coating thickness was modeled based on Faraday's law of electrolysis and the geometry of drive shaft, wheel, and diamond grit. To validate the miniature wheel performance in atherectomy, grinding experiments were conducted on an atherectomy cardiovascular simulator with a calcified plaque surrogate. The wheel motion, material removal rate, and wheel surface wear were studied via high-speed camera imaging and laser confocal microscopy. The grinding wheel with 80,000 rpm rotational speed had an orbital speed of 14,300 rpm around the 1.5 mm diameter plaque surrogate lumen. After grinding for 120 s, the plaque surrogate inner diameter was enlarged to 3.03 mm, and no wear or loss of diamond abrasive was observed on the grinding wheel. This study demonstrated that the proposed electroplating process for fabricating miniature grinding wheels could effectively remove the calcified plaque surrogate. This research could lead to a more effective and safer atherectomy device with sub-mm miniature diamond wheels to treat lesions deep in coronary and peripheral arteries.

Specialty Balloons for Vessel Preparation During Infrainguinal Endovascular Revascularization Procedures: A Review of Literature

Balloon angioplasty with/without utilizing drug eluting technology or stenting constitutes the treatment of choice for a significant percentage of patients with peripheral artery disease requiring an intervention. However, in cases of diffuse disease and plaque complexity, angioplasty may lead to dissection, recoil, and/or early restenosis, making vessel preparation a key component for successful and durable endovascular revascularization outcome. This review of literature aims to present contemporary data for several commercially available specialty balloons that have been designed to minimize the arterial wall stress of conventional balloon angioplasty and facilitate technical success, as well as long-term patency.

Clinical Outcomes of Left Main Coronary Artery PCI With Rotational Atherectomy

Data regarding rotational atherectomy percutaneous coronary intervention (RA PCI) angioplasty in the left main (LM) coronary artery are scarce, and mostly outdated. We aimed to describe clinical outcomes of RA PCI in LM. Patients requiring RA in 8 European countries and 19 centers were prospectively and consecutively included in the European registry of Cardiac Care of Calcified and Complex patients registry. In-hospital data collection and 1-year follow-up were performed for each patient. Between October 2016 and July 2018, 966 patients with complete data were included. Among them, 241 presented with an LM lesion, and 171 required an LM lesion preparation by RA. The latter, allocated to the LM-RA group, were compared with the 725 patients in the non-LM-RA group. Clinical success of the RA procedure was comparable in both groups, but in-hospital major adverse cardiac events were higher in the RA-LM group (7.6% vs 3.2%, adjusted p = 0.04), mainly driven by a higher in-hospital mortality rate (5.3 vs 0.3%, adjusted p = 0.005). At 1-year follow-up, mortality and major adverse cardiac event rates were comparable in both groups (12.9% vs 8.0%, adjusted p value: 0.821, and 15.8% vs 10.9%, adjusted p value: 0.329, respectively), but the rate of target vessel revascularization remained higher in the RA-LM group (5.3% vs 3.2%, adjusted p = 0.021). In conclusion, RA PCI is an efficient option for calcified LM lesions, providing acceptable outcomes regarding this population with high risk at 1 year, and yields comparable outcomes with RA PCI performed on non-LM lesions.

Management of Acute Complications during Endovascular Procedures in Peripheral Arterial Disease: A Review

Endovascular therapy, as opposed to surgical bypass, has become the mainstay for peripheral arterial disease even in long segment occlusions. Complications can occur during the arterial access, catheter manipulation, balloon dilation, and/or stent placement. Given the high prevalence of comorbidities such as diabetes, hypertension, renal dysfunction, and coronary artery disease in these patients, early identification of procedural complications and initiation of treatment are of paramount importance. This review aims to provide comprehensive data on the identification and management of commonly encountered endovascular complications during endovascular interventions in peripheral arterial disease.

A State-of-the-Art Review: The Percutaneous Treatment of Highly Calcified Lesions

Coronary artery calcification is prevalent in coronary heart disease with its progression being predictive of future adverse cardiac events. Its presence is considered to be a marker of interventional procedural complexity. Several adjunctive percutaneous coronary intervention tools, such as modifying balloons, atherectomy devices and intravascular lithotripsy, now exist to successfully treat calcified lesions. In this state-of-the-art review, a step-wise progression of strategies is described to modify coronary plaque, from well-recognised techniques to techniques that should only be considered when standard manoeuvres have proven unsuccessful. Technology has advanced greatly over the past few decades and we discuss how future technologies might shape percutaneous intervention.

Excimer laser atherectomy combined with drug-coated balloon angioplasty for the treatment of femoropopliteal arteriosclerosis obliterans

INTRODUCTION

It has been reported that excimer laser atherectomy combined with a drug-coated balloon (ELA+DCB) can achieve better results than simple balloon angioplasty, especially for the treatment of femoropopliteal in-stent restenosis. However, reports on the application of ELA+DCB in China for femoropopliteal arteriosclerosis obliterans are lacking. This study focuses on analysing the effectiveness and safety of ELA+DCB.

METHODS

This was a single-centre retrospective study that enrolled patients from November 2016 to January 2019 who had femoropopliteal arteriosclerosis obliterans treated by ELA+DCB. Preoperative demographics, operative details and postoperative follow-up outcomes were analysed statistically.

RESULTS

There were 43 patients with an average patient age of 68.0±8.6 years; 79.1% were male. In 30 cases, the lesions were de novo and the others were in-stent restenosis (ISR). During the procedure, flow-limiting dissection (48.8%) was the main adverse event and there were 17 bailout stent implantations due to dissection. Mean (±sd) ankle-brachial index (ABI) in the patients was 0.42±0.31 before the operation and 0.83±0.13 before discharge. The mean (±sd) follow-up time was 29.35±9.71 months. The primary patency rate was 66.8%, 64.3% and 60.9% at 12, 24 and 36 months. Freedom from target lesion revascularisation (TLR) was 85.7%, 80.7% and 75.3% at 12, 24 and 36 months. Rutherford categories also greatly improved during follow-up. Overall mortality was 6.9% (3/48), and no deaths were related to the intervention.

CONCLUSION

The use of ELA+DCB had good clinical benefit for femoropopliteal arteriosclerosis obliterans, which had good primary patency and freedom from TLR, although intraoperative complications still required attention. Multicentre randomised controlled trials with long-term follow-up are needed.

Nanoparticle coatings for controlled release of quercetin from an angioplasty balloon

Peripheral artery disease (PAD) is a systemic vascular disease of the legs that results in a blockage of blood flow from the heart to the lower extremities. Now one of the most common causes of mortality in the U.S., the first line of therapy for PAD is to mechanically open the blockages using balloon angioplasty. Coating the balloons with antiproliferative agents can potentially reduce vessel re-narrowing, or restenosis after surgical intervention, but current drug-coated balloons releasing chemotherapy agents like paclitaxel have in some cases shown increased mortality long-term. Our aim was to design a novel drug-coated balloon using a polymeric nanodelivery system for a sustained release of polyphenols that reduce restenosis but with reduced toxicity compared to chemotherapy agents. Poly (lactic-co-glycolic acid) (PLGA) nanoparticles with entrapped quercetin, a dimethoxy quercetin (rhamnazin), as well as quercetin covalently attached to PLGA, were developed. Balloon catheters were coated with polymeric nanoparticles using an ultrasonic method, and nanoparticle characteristics, drug loading, coating uniformity and drug release were determined. The adhesion of nanoparticles to vascular smooth muscle cells and the antiproliferative effect of nano-delivered polyphenols were also assessed. Of the nanoparticle systems tested, those with covalently attached quercetin provided the most sustained release over a 6-day period. Although these particles adhered to cells to a smaller extent compared to other nanoparticle formulations, their attachment was resistant to washing. These particles also exhibited the greatest anti-proliferative effect. In addition, their attachment was not altered when the cells were grown in calcifying conditions, and in PAD tissue calcification is typically a condition that impedes drug delivery. Moreover, the ultrasonic coating method generated a uniform balloon coating. The polymeric nanoparticle system with covalently attached quercetin developed herein is thus proposed as a promising platform to reduce restenosis post-angioplasty.

Use of a Cutting Balloon Reduces the Incidence of Distal Embolism in Acute Coronary Syndrome Requiring Predilatation Before Stenting

Background: Acute coronary syndrome (ACS) patients with solid lesions often require predilatation before stenting. Predilatation with high pressure may increase the risk of distal embolism, whereas direct stenting increases the risk of stent underexpansion. We recently reported that, in severely calcified lesions, using a cutting balloon (CB) can provide greater acute gain compared with other scoring balloons. Therefore, we hypothesized that predilatation with CB may reduce the incidence of distal embolism in ACS patients with solid lesions.

Methods and Results: This study retrospectively analyzed data for 175 ACS patients who required predilatation, either with a conventional balloon (n=136) or CB (n=39). The occurrence of distal embolism was significantly lower in the CB than conventional balloon group (10.3% vs 32.4%, respectively; P=0.007). Multivariate analysis showed that the occurrence of distal embolism was positively associated with Thrombolysis in Myocardial Infarction (TIMI) grade and the presence of attenuated plaque, but negatively associated with the use of a CB. To support this clinical observation, we compared thrombus dispersal using a CB and non-compliant balloon in an ex vivo experimental model using a pseudo-thrombus. In this model, pseudo-thrombus dispersal was significantly smaller when a CB rather than non-compliant balloon was used (1.8±1.0% vs 2.6±1.2%, respectively; n=20, for each; P=0.002).

Conclusions: In ACS patients with solid lesions that require predilatation, predilatation with a CB may reduce the incidence of distal embolism.

Phoenix atherectomy for patients with peripheral artery disease

BACKGROUND

Endovascular atherectomy enables minimally invasive plaque removal in peripheral artery disease (PAD).

AIMS

We aimed to evaluate the safety and the long-term effectiveness of the Phoenix atherectomy for the treatment of complex and calcified lesions in PAD patients.

METHODS

Consecutive all-comer patients with PAD underwent the Phoenix atherectomy. Device safety in terms of perforation and distal embolisation were evaluated. Lesion calcifications were categorised by the Peripheral Arterial Calcium Scoring System (PACSS) and lesion complexity was assessed by the Transatlantic Inter-Society Consensus (TASC). Clinically driven target lesion revascularisation (TLR) was assessed.

RESULTS

A total of 558 lesions were treated in 402 consecutive patients. Clinical follow-up was available at 15.7±10.2 months for 365 (91%) patients. Of 402 patients, 135 (33.6%) had claudication, 37 (9.2%) had ischaemic rest pain and 230 (57%) exhibited ischaemic ulcerations. Lesions were mostly identified in the femoropopliteal segments (55%), followed by below-the-knee (BTK) segments (32%). Complex TASC C/D lesions and moderate to severe calcifications (PACSS score ≥2) were present in 331 (82%) and 323 (80%) patients, respectively. The mean lesion length was 20.6±14.3 cm. Five (1%) perforations and 10 (2%) asymptomatic embolisations occurred. Bail-out stenting was performed in 4%, 16% and 3% of patients with common femoral artery, femoropopliteal and BTK lesions, respectively. During follow-up, 5 (3.9%) patients with claudication and 52 (21.9%) patients with critical limb-threatening ischaemia (CLTI) died (hazard ratio [HR] 3.7; p<0.001). Freedom from TLR was 87.5% (112 of 128) in patients with claudication and 82.3% (195 of 237) in patients with CLTI, respectively (HR 1.8; p=0.03).

CONCLUSIONS

The Phoenix atherectomy can be safely performed in patients with complex lesions with a relatively low rate of bail-out stenting and clinically acceptable TLR rates.

GERMAN CLINICAL TRIALS REGISTER

DRKS00016708.

High-speed rotational atherectomy in coronary artery calcification: The randomized ROTAXUS and PREPARE-CALC trials

BACKGROUND

The clinical outcomes of high-speed rotational atherectomy (RA) to optimize target lesion preparation in coronary artery calcification (CAC) have been examined in several trials.

AIMS

This study was conducted to evaluate the safety and efficacy of RA for CAC.

METHODS

Patient data were pooled from ROTAXUS and PREPARE-CALC. The primary endpoint was the in-stent late lumen loss and major adverse cardiac events (MACE) at 9 months. Secondary endpoints included in-segment late lumen loss, binary restenosis, strategy success, procedural duration, and contrast amount.

RESULTS

Four hundred and forty patients were enrolled from Germany in this study, 220 patients were randomized to the RA group and 220 patients were randomized to the Control group. Despite similar baseline characteristics, significantly more patients in the Control group were crossover (14.1% vs. 2.3%, p < 0.0001), resulting in higher strategy success in the RA group (95.0% vs. 82.3%, p < 0.0001). At 9 months, in-stent late lumen loss was higher in the RA group (0.34 ± 0.52 mm vs. 0.24 ± 0.47 mm, p = 0.03) and procedural duration was longer in the RA group (76.3 ± 41.8 min vs. 67.0 ± 38.8 min, p = 0.02). MACE (17.8% vs. 25.2%, p = 0.06), in-segment late lumen loss (0.28 ± 0.66 mm vs. 0.17 ± 0.55 mm, p = 0.05), binary restenosis (7.3% vs. 8.2%, p = 0.71 in-stent; 7.7% vs. 9.0%, p = 0.62 in-segment), and contrast amount (215.5 ± 112.5 ml vs. 203.7 ± 96.5 ml, p = 0.24) were similar in both groups.

CONCLUSION

Lesion preparation with upfront RA before drug-eluting stent implantation is feasible in CAC, is more strategy successful, and is associated with excessive in-stent late lumen loss and excellent clinical outcomes at 9 months although longer procedural duration.

Orbital Atherectomy Prior to Drug-Coated Balloon Angioplasty in Calcified Infrapopliteal Lesions: A Randomized, Multicenter Pilot Study

PURPOSE

Optimal balloon angioplasty for infrapopliteal lesions is often limited by severe calcification, which has been associated with decreased procedural success and lower long-term patency.

MATERIALS AND METHODS

This was a prospective, randomized, multicenter pilot trial that included adult subjects with calcified lesions located from the popliteal segment below the knee (BTK) joint to within 5 cm above the ankle with ≥70% diameter stenosis by angiography. Patients were randomized 1:1 to undergo orbital atherectomy (OA) with adjunctive drug-coated balloon (DCB) angioplasty versus plain balloon angioplasty (BA) and DCB angioplasty (control). The periprocedural and 12 month outcomes of both procedures were compared.

RESULTS

Overall, 66 subjects (OA + DCB = 32 vs control = 34) were included in an intention to treat analysis. Baseline demographics and lesion characteristics were well-balanced. The mean lesion length was 101.3 mm (SD = 72.8 mm) and 78.8 (SD = 61.0 mm) in the OA + DCB and control groups, respectively, with almost all lesions having severe calcification per the Peripheral Academic Research Consortium (PARC) criteria. Chronic total occlusions (CTOs) were present in 43.8% and 35.3% of the patients in the OA + DCB and control groups, respectively. The technical success of OA + DCB versus DCB was 81.8% and 89.2%, respectively, with 3 slow flow/no reflow, 1 perforation, 1 severe dissection occurred in OA + DCB group, and one distal embolization occurred in the control group. The target lesion primary patency rate was numerically higher in the OA + DCB versus control group at 6 (88.2% vs 50.0%, p=0.065) and 12 month follow-up (88.2% vs 54.5%, p=0.076). The 12 month freedom from major adverse events, clinically-driven target lesion revascularization, major amputation, and all-cause mortality rates were similar between both groups.

CONCLUSION

The results of the Orbital Vessel PreparaTIon to MaximIZe Dcb Efficacy in Calcified BTK (OPTIMIZE BTK) pilot study indicated that utilization of OA + DCB is safe for infrapopliteal disease. Further prospective adequately powered studies should investigate the potential benefit of combined OA + DCB for BTK lesions.

Arterial Preparation by Longitudinal Micro-Incisions Before Balloon Angioplasty of the Superficial Femoral and Popliteal Artery: Acute and 12-Month Results

PURPOSE

Percutaneous transluminal angioplasty (PTA) with conventional plain old balloon (POBA) and/or drug-coated balloon (DCB) is the primary intervention to treat peripheral artery stenoses. However, acute dissections during the procedure and potential for future target lesion revascularization remain procedural complications. The purpose of this study was to assess the acute and 12-month outcomes in patients who underwent novel vessel preparation with longitudinal, controlled-depth micro-incisions prior to PTA.

MATERIALS AND METHODS

Patients with symptomatic lower extremity peripheral arterial disease with a Rutherford class of 2 to 6 and >70% de novo stenosis of the superficial femoral or popliteal arteries were included in this retrospective study. Patients with thrombotic or embolic lesions, restenosis, or in-stent restenosis were excluded. The FLEX Vessel Prep System (FLEX VP) was used to prepare the vessel prior to PTA by creating micro-incisions at the target lesion. The FLEX VP was followed by POBA or paclitaxel DCB.

RESULTS

The study included 65 patients. Lesion characteristics were 90% median stenosis (range = 70%-100%), 75.4% mild-to-severe calcifications, and 33.8% occlusion rate, and median lesion length was 196 (range = 10-480) mm. Following vessel preparation, 82.1% of the patients had low severity dissection or no flow-limiting dissection. The provisional stent rate postprocedure was 16.9%, with a median stent length of 60 mm. The freedom from target lesion revascularization (FFTLR) in 63 evaluable patients at 6 and 12 months was 98.4% and 93.7%, respectively. Freedom from amputation was 100%.

CONCLUSION

In this real-world/all-comers patient population with long, stenotic lesions across the calcification spectrum, vessel preparation with longitudinal micro-incisions prior to PTA was associated with low dissection rate, low dissection severity, low stent implantation, and high FFTLR with the absence of amputation at 12 months relative to published reports in long-lesion cohorts. These results support vessel preparation via micro-incisions.

Japan-USA orbital atherectomy for calcific coronary lesions: COAST study, Hharmonization by Doing proof-of-concept

Effective treatment strategies and medical devices continue to be needed in Japan and the United States of America (US) to mitigate the growing burden of cardiovascular disease and coronary heart disease. Unfortunately, there can be a delay in gaining cardiovascular device approval in Japan after a device has already been approved and is in use in the US. The Harmonization by Doing (HBD) program; however, can eliminate this delay and reduce the cost of completing a clinical trial in Japan. The HBD proof-of-concept study, COAST, resulted in approval of the Diamondback 360® Coronary Orbital Atherectomy System Micro Crown simultaneously in Japan and the US on the same day. Subsequently, the Diamondback 360® Coronary OAS Classic Crown also received approval in Japan. The COAST study provides further evidence that global clinical trials via HBD for medical devices are practical and advantageous.

Predictive Factors of Severe Dissection after Balloon Angioplasty for Femoropopliteal Artery Disease

BACKGROUND

Arterial dissection is one of the mechanisms of balloon angioplasty. Although some degree of dissection is unavoidable, severe dissection that impedes blood flow decreases patency and increases the need for additional procedures. To improve the results of angioplasty, it is necessary to understand the factors related to severe dissection and make efforts to reduce its occurrence. This study aimed to elucidate the predictive and protective factors associated with severe dissection in femoropopliteal balloon angioplasty.

METHODS

This was a retrospective, single-center, nonrandomized study. A total of 409 limbs were studied in 334 patients with symptomatic femoropopliteal lesions treated between 2010 and 2019. Dissections after initial balloon angioplasty were classified according to the Kobayashi dissection classification (grade A: no dissection; B: mild dissection <1/3 of the lumen; C: severe dissection, ≥1/3 of the lumen) into the nonsevere dissection group (grades A and B), and severe dissection group (grade C). We compared clinical, procedural and lesion-related characteristics between the 2 groups. Factors with statistical significance in univariate analyses were entered into a multivariate logistic regression model to identify independent predictive factors of severe dissection.

RESULTS

Severe dissection occurred in 237 limbs and nonsevere dissection in 172 limbs. In univariate analyses, the predictive factors of severe dissection were TransAtlantic Inter-Society Consensus II C/D grades (P < 0.001), lesion length ≥15cm (P < 0.001), chronic total occlusion (P = 0.004), and degree of stenosis ≥70% (P < 0.001). Protective factors for severe dissection were end-stage renal disease (P = 0.008), severe calcification >50% (P < 0.001), and the use of a scoring balloon (P = 0.001). In multivariate analysis, factors associated with severe dissection were lesion length ≥15cm (OR, 2.259; 95% CI: 1.417-4-3.601), occlusion or degree of stenosis ≥70% (OR, 1.931; 95% CI: 1.255-2.971), severe calcification (OR, 0.520; 95% CI: 0.338-0.800), and the use of a scoring balloon (OR, 0.467; 95% CI: 0.263-0.830).

CONCLUSIONS

Lesion length ≥15cm and occlusion or stenosis ≥70% were identified as independent predictive factors of severe dissection in femoropopliteal artery balloon angioplasty. Conversely, severe calcification and the use of a scoring balloon appeared to be protective factors against severe dissection.

Intravascular Lithotripsy for Treatment of Calcified Infrapopliteal Lesions: Results from the Disrupt PAD III Observational Study

PURPOSE

To evaluate the safety and effectiveness of the Shockwave S⁴ intravascular lithotripsy (IVL) catheter in an "all-comers" cohort of patients with calcified infrapopliteal lesions.

MATERIALS AND METHODS

The Disrupt PAD III Observational Study (NCT02923193) is a prospective, nonrandomized, multicenter single-arm study designed to assess the "real-world" acute safety and effectiveness of the Shockwave Peripheral IVL System for the treatment of de novo calcified, stenotic peripheral arteries. Patients were eligible for enrollment if they had claudication or critical limb ischemia (CLI) and at least moderate calcification as assessed by angiography. This subanalysis includes consecutive patients enrolled with angiographic core lab-assessed treatment of infrapopliteal arteries using the Shockwave S⁴ IVL catheter.

RESULTS

From July 2018 to August 2020, 101 patients with 114 calcified infrapopliteal arteries treated with the S⁴ IVL catheter were enrolled at 15 sites in 3 countries. CLI was present in 69.3% of patients. The anterior tibial and tiboperoneal trunk were the most commonly treated vessels with an overall mean reference vessel diameter (RVD) of 3.1±0.8 mm, minimum lumen diameter (MLD) of 0.5±0.6 mm, and a corresponding diameter stenosis of 83.4%±15.8% by core lab assessment. Mean lesion length was 64.7±54.7 mm with moderate to severe calcification in 69.3% of lesions by the Peripheral Academic Research Consortium (PARC) criteria. Adjunctive calcium-modifying technology, defined as scoring or cutting balloon and/or atherectomy, was used in 22.7% of procedures. The average acute gain at the end of the procedure was 2.0±0.7 mm with a residual stenosis <50% achieved in 99.0% of lesions and a mean residual stenosis of 23.3±12.5%. There were no flow-limiting dissection, embolization, slow flow/no-reflow, or abrupt closure events at the end of the procedure.

CONCLUSION

This subanalysis of the PAD III Observational Study represents the largest report to-date of IVL treatment of heavily calcified below-the-knee (BTK) lesions in a "real-world" patient cohort. The use of S⁴ IVL demonstrated consistent acute safety and effectiveness outcomes consistent with prior IVL peripheral studies. These consistent outcomes were achieved with the initial use of the S⁴ IVL catheter for treatment of complex BTK lesions.

Characteristics and hospital outcomes of coronary atherectomy within the United States: a multivariate and propensity-score matched analysis

BACKGROUND

Suboptimal stent delivery and deployment in calcified coronary lesions are associated with a poor clinical outcome.

METHODS

Using the National Inpatient Sample database, we identified patients undergoing percutaneous coronary intervention (PCI). Comparison between procedural and hospital outcomes between patients who underwent atherectomy and those who did not.

RESULTS

A total of 2,035,039 patients underwent PCI, of which 50,095 (2.4%) underwent lesion modification using atherectomy. After adjustment for baseline differences, patients who underwent atherectomy were found to have higher rates of in-hospital mortality (3.3% vs 2.2% adjusted Odds Ratio, aOR, 1.39; 95% confidence interval [CI], 1.31-1.46, P < 0.001), coronary artery dissection (1.7% vs 1.1%, aOR, 1.56; 95%, 1.45-1.67, P < 0.001) vascular complications (1.6% vs 1.0%, aOR, 1.52; 95%, 1.42-1.64, P < 0.001), major bleeding (6.3% vs 4.7%, aOR, 1.24; 95%, 1.18-1.28, P < 0.001), and acute kidney injury (AKI) (10.9%vs 9.1%, aOR, 1.07; 95%, 1.04-1.11, P < 0.001) when compared with non-atherectomy patients. Concomitant intravascular ultrasound (IVUS) imaging improved mortality, while other complication rates were not affected by imaging.

CONCLUSION

Coronary atherectomy was performed in patients with multiple comorbidities and was associated with higher in-hospital mortality and complications than the non-atherectomy group.

New Advances in the Treatment of Severe Coronary Artery Calcifications

Coronary artery calcifications are always challenging scenarios for interventional cardiologists. Calcium content in coronary tree directly correlates with male sex, age, Caucasian ethnicity, diabetes, and chronic kidney disease. Intracoronary imaging is useful and necessary to understand calcific lesion features and plan the best percutaneous coronary intervention strategy. Thus, accurate evaluation of patient and lesion characteristics is crucial. For this reason, definition of calcific arc, length, and thickness can suggest the best procedure before stenting and final optimization. In our modern era, different devices are available and all are surprisingly promising.

miR-204: Molecular Regulation and Role in Cardiovascular and Renal Diseases

The field of microRNA research has evolved from studies aiming to gauge the importance of microRNAs to those focusing on understanding a subset of specific microRNAs that have emerged as potent regulators of molecular systems and pathophysiological conditions. In this article, we review the molecular features and regulation of miR-204 and the growing body of evidence for an important role of miR-204 in the regulation of cardiovascular and renal physiology and pathophysiological processes. miR-204 exhibits a highly tissue-specific expression pattern, and miR-204 abundance is regulated by several transcriptional and posttranscriptional mechanisms. Strong evidence supports a role for miR-204 in attenuating pulmonary arterial hypertension and hypertensive and diabetic renal injury while promoting hypertension and endothelial dysfunction in a wide range of model systems. miR-204 may influence these disease processes by targeting several biological pathways in a tissue-specific manner. miR-204 is dysregulated in patients with cardiovascular and renal diseases. The unequivocal functional roles and clear clinical relevance indicate that miR-204 is a high-value microRNA in cardiovascular and renal diseases.

Atherectomy Combined with Balloon Angioplasty versus Balloon Angioplasty Alone for de Novo Femoropopliteal Arterial Diseases: A Systematic Review and Meta-analysis of Randomised Controlled Trials

OBJECTIVE

The efficacy and cost effectiveness of atherectomy for femoropopliteal (FP) arterial diseases have not been determined yet. A systematic review and meta-analysis were performed to compare the efficacy and safety between atherectomy combined with balloon angioplasty (BA) and BA alone for patients with de novo FP steno-occlusive lesions.

METHODS

The Cochrane Library, Medline, and Embase were used to search for studies evaluating outcomes of atherectomy combined with BA compared with BA alone in FP arterial diseases from inception to July 2020. The methodological quality of the included studies was evaluated with the Cochrane Risk of Bias Tool. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework was used to assess the level of evidence for each outcome. The fixed effects model was chosen to combine the data when I² < 50%; otherwise, the random effects model was used. Subgroup and sensitivity analyses were performed to further analyse the results.

RESULTS

Four RCTs were included. The meta-analysis showed that atherectomy combined with BA was associated with improved technical success rate (risk ratio [RR] 0.22, 95% confidence interval [CI] 0.13-0.38, p < .001; I² = 0; high quality), reduced bailout stenting (RR 0.15, 95% CI 0.07-0.32, p < .001; I² = 16%; high quality), and flow limiting dissection (RR 0.24, 95% CI 0.13-0.47, p < .001; I² = 0; high quality). No statistically significant difference was found in target lesion revascularisation (TLR), primary patency, mortality, major adverse event (MAE), or ankle brachial index (ABI) after one year follow up.

CONCLUSION

Compared with BA alone, atherectomy combined with BA may not improve primary patency, TLR, mortality rate, or ABI, but may reduce the need for bailout stenting and the incidence of flow limiting dissection and increase the technical success rate in FP arterial diseases. More studies are warranted to further confirm the conclusion.

Mechanical performances of balloon post-dilation for improving stent expansion in calcified coronary artery: Computational and experimental investigations

Stent deployment in a calcified coronary artery is often associated with suboptimal outcomes such as stent underexpansion and malapposition. Post-dilation after stent deployment is commonly used for optimal stent implantation. There is no guideline for choosing the post-dilation balloon diameter and inflation pressure. In this work, ex-vivo/in-silico experiments were performed to investigate the efficacy of post-dilation balloon diameter and inflation pressure in improving the stent expansion in a calcified lesion. Post-dilations with three balloon diameters (3 mm, 3.5 mm, and 4 mm) were performed. For each balloon diameter, three inflation pressures (10 atm, 20 atm, and 30 atm) were sequentially applied. In ex-vivo experiments, optical coherence tomography images were acquired during the stenting procedure, i.e., pre- and post-deployment of 3 mm diameter stent, as well as after each post-dilation. The results from in-silico experiments were compared with ex-vivo experiments in terms of lumen area. In addition, stretch ratio analysis was developed to predict the stent-induced lumen area, along with the strain analysis and the in-silico experiments. Results have shown that target lumen area could be achieved with an oversized nominal balloon diameter of +0.5 mm (i.e., 0.5 mm greater than reference lumen diameter) at an inflation pressure of 20 atm. After each post-dilation, fibrotic tissue demonstrated a larger strain, contributing to improved lumen gain. However, minimal changes were observed in calcification. Moreover, a strong correlation (R² = 0.95) between the stretch ratio of fibrotic tissue and lumen area after each post-dilation was observed. This indicated that the morphology of the fibrotic tissue could be a potential marker to predict the lumen gain. The detailed mechanistic quantifications of a single lesion cannot be generalized to all clinical cases. However, this work could be used to provide a fundamental understanding of the post-dilations, to develop experimental protocols for producing generalized guidelines, and to exploit their potential for optimal pre- and post-stent strategies.

Association of Postangioplasty Femoropopliteal Dissections With Outcomes After Drug-Coated Balloon Angioplasty in the Femoropopliteal Arteries

PURPOSE

Balloon angioplasty for the treatment of femoropopliteal lesions is often complicated by postangioplasty dissections. While dissections are known to affect patency and reintervention after balloon angioplasty, the association between dissections and major adverse limb event (MALE) after drug-coated balloon (DCB) angioplasty remains uncertain. Thus, the postangioplasty dissection and bailout stenting patterns were investigated.

MATERIALS AND METHODS

This was a single-center retrospective study enrolling patients with de novo femoropopliteal lesions treated with DCB with/without stenting. Postangioplasty target vessel dissection was graded based to the coronary artery classification grades A-F, with grade C-F considered "severe." Cox regression analysis was performed to examine the association of dissection severity with outcomes during 2-year follow up, among nonstented cases.

RESULTS

In 85.3% of the cases (N=203/238) a postangioplasty dissection was observed. The average dissection length was 55.57 mm (SD 36.71 mm), with 1 dissection present in 91.8% (N=180/196) and 2 or more dissections present in 8.2% (N=16/196). Dissection severity was grade A (19.8%), B (20.6%), C (23.1%), D (10.9%), E (10.1%), and F (0.8%). Bailout stenting was required in 40.4% of the patients, being more prevalent among grade C and grade E cases. Among 142 nonstented cases, dissections were present in 85.2%. A total of 75 (52.8%) of these dissections were grade A and B, while 46 (32.4%) were grade C to F. Among nonstented cases, grade C (hazard ratio [HR] 5.83; 95% CI 1.25 to 27.31; p=0.025) and grade D (HR 6.32; 95% CI 1.39 to 28.86; p=0.017) vs grade A dissections were associated with a higher risk for 2-year MALE. Multivariate analysis adjusting for several lesion characteristics demonstrated a statistically significant higher risk for 2-year MALE among the severe dissection group (HR 2.94; 95% CI 1.27 to 6.79; p = 0.012). Interestingly, the risks of limb loss (HR 1.30; 95% CI 0.22 to 7.79; p=0.774) and repeat revascularization (HR 0.95; 95% CI 0.40 to 2.26; p=0.905) during follow-up were similar between the 2 groups.

CONCLUSION

This study indicated that nonstented moderate and severe postangioplasty dissections after DCB angioplasty were associated with higher risk for MALE. Future studies are needed to validate our results and determine other dissection characteristics (eg, total dissection length, lumen area, total number of dissections) that may affect the efficacy of DCB.

Finite element analysis of cutting balloon expansion in a calcified artery model of circular angle 180°: Effects of balloon-to-diameter ratio and number of blades facing calcification on potential calcification fracturing and perforation reduction

Calcified artery lesions cause stent under-expansion and increase the risk of in-stent restenosis and stent thrombosis. Cutting balloons facilitate the fracturing of calcification prior to stent implantation, although vessel dissection and perforation are potential issues. In clinical practice, calcifications having maximum calcium angles ≤ 180° are rarely fractured during conventional balloon angioplasty. We hypothesize that the lesion/device diameter ratio and the number of blades facing a non-circular calcified lesion may be crucial for fracturing the calcification while avoiding vessel injury. The geometries of the cutting balloons were constructed and their finite-element models were generated by folding and wrapping the balloon model. Numerical simulations were performed for balloons with five different diameters and two types of blade directions in a 180° calcification model. The calcification expansion ability was distinctly higher when two blades faced the calcification than when one blade did. Moreover, when two blades faced the calcification model, larger maximum principal stresses were generated in the calcification even when using undersized balloons with diameters reduced by 0.25 or 0.5 mm from the reference diameter, when compared with the case where one blade faced the calcified model and a balloon of diameter equal to the reference diameter was used. When two blades faced the calcification, smaller stresses were generated in the artery adjacent to the calcification; further, the maximum stress generated in the artery model adjacent to the calcification under the rated pressure of 12 atm when employing undersized balloons was smaller than that when only one blade faced the calcification and when lesion-identical balloon diameters were used under a nominal pressure of 6 atm. Our study suggested that undersized balloons of diameters 0.25 or 0.5 mm less than the reference diameter might be effective in not only expanding the calcified lesion but also reducing the risk of dissection.

Colocalization of Erythrocytes and Vascular Calcification in Human Atherosclerosis: A Systematic Histomorphometric Analysis

Background  Intimal calcification typically develops in advanced atherosclerosis, and microcalcification may promote plaque progression and instability. Conversely, intraplaque hemorrhage and erythrocyte extravasation may stimulate osteoblastic differentiation and intralesional calcium phosphate deposition. The presence of erythrocytes and their main cellular components (membranes, hemoglobin, and iron) and colocalization with calcification has never been systematically studied. Methods and Results  We examined three types of diseased vascular tissue specimens, namely, degenerative aortic valve stenosis ( n  = 46), atherosclerotic carotid artery plaques ( n  = 9), and abdominal aortic aneurysms ( n  = 14). Biomaterial was obtained from symptomatic patients undergoing elective aortic valve replacement, carotid artery endatherectomy, or aortic aneurysm repair, respectively. Serial sections were stained using Masson-Goldner trichrome, Alizarin red S, and Perl's iron stain to visualize erythrocytes, extracelluar matrix and osteoid, calcium phosphate deposition, or the presence of iron and hemosiderin, respectively. Immunohistochemistry was employed to detect erythrocyte membranes (CD235a), hemoglobin or the hemoglobin scavenger receptor (CD163), endothelial cells (CD31), myofibroblasts (SMA), mesenchymal cells (osteopontin), or osteoblasts (periostin). Our analyses revealed a varying degree of intraplaque hemorrhage and that the majority of extravasated erythrocytes were lysed. Osteoid and calcifications also were frequently present, and erythrocyte membranes were significantly more prevalent in areas with calcification. Areas with extravasated erythrocytes frequently contained CD163-positive cells, although calcification also occurred in areas without CD163 immunosignals. Conclusion  Our findings underline the presence of extravasated erythrocytes and their membranes in different types of vascular lesions, and their association with areas of calcification suggests an active role of erythrocytes in vascular disease processes.

Procedural effectiveness with a focused force scoring angioplasty catheter: Procedural and clinical outcomes from the Scoreflex NC trial

BACKGROUND

The Scoreflex NC scoring angioplasty catheter is designed with a short rapid-exchange tip distal to a non-compliant, high-pressure balloon and an integral wire outside of the balloon, such that the guidewire and the integral wire act as scoring elements during balloon inflation. The external scoring elements enable a focal stress pattern facilitating expansion of resistant lesions at lower pressures using a focused force angioplasty effect.

METHODS

Patients undergoing elective percutaneous coronary intervention (PCI) were enrolled in a prospective, single-arm study conducted at 12 centers in the United States. The primary endpoint was device procedural success, defined as the composite of successful device delivery to the target lesion with balloon inflation and deflation; absence of vessel perforation, flow-limiting dissection or reduction in TIMI flow from baseline; and achievement of final TIMI 3 flow.

RESULTS

Among 200 patients (234 lesions), lesion complexities included: bifurcation disease (37.6%), moderate/severe calcification (36.6%), and total occlusions (5.0%). Successful delivery to the target lesion, inflation and removal of the balloon catheter was achieved in 95.5% of patients (191/200). Procedural success was achieved in 93.5% (187/200) of patients, and final TIMI 3 flow was observed in 99.0% of cases (198/200). No unanticipated device-related events occurred. In-hospital major adverse events were reported in 4.5% of patients (9/200), related to periprocedural myocardial infarction (8/200, 4.0%) and target lesion revascularization (1/200, 0.5%).

CONCLUSIONS

Among patients undergoing elective PCI and with varied lesion complexity, these results support the safety and effectiveness of a dilation strategy using the Scoreflex NC scoring catheter.

Multi-modality intravascular imaging for guiding coronary intervention and assessing coronary atheroma: the Novasight Hybrid IVUS-OCT system

Intravascular imaging has evolved alongside interventional cardiology as an adjunctive tool for assessing plaque pathology and for guiding and optimising percutaneous coronary intervention (PCI) in challenging lesions. The two modalities which have dominated the field are intravascular ultrasound (IVUS), which relies on sound waves and optical coherence tomography (OCT), relying on light waves. These approaches however have limited efficacy in assessing plaque morphology and vulnerability that are essential for guiding PCI in complex lesions and identifying patient at risk that will benefit from emerging therapies targeting plaque evolution. These limitations are complementary and, in this context, it has been recognised and demonstrated in multi-modality studies that the concurrent use of IVUS and OCT can help overcome these deficits enabling a more complete and accurate plaque assessment. The Conavi Novasight Hybrid IVUS-OCT catheter is the first commercially available device that is capable of invasive clinical coronary assessment with simultaneously acquired and co-registered IVUS and OCT imaging. It represents a significant evolution in the field and is expected to have broad application in clinical practice and research. In this review article we present the limitations of standalone intravascular imaging techniques, summarise the data supporting the value of multimodality imaging in clinical practice and research, describe the Novasight Hybrid IVUS-OCT system and highlight the potential utility of this technology in coronary intervention and in the study of atherosclerosis.

From organic and inorganic phosphates to valvular and vascular calcifications

Calcification of the arterial wall and valves is an important part of the pathophysiological process of peripheral and coronary atherosclerosis, aortic stenosis, ageing, diabetes, and chronic kidney disease. This review aims to better understand how extracellular phosphates and their ability to be retained as calcium phosphates on the extracellular matrix initiate the mineralization process of arteries and valves. In this context, the physiological process of bone mineralization remains a human model for pathological soft tissue mineralization. Soluble (ionized) calcium precipitation occurs on extracellular phosphates; either with inorganic or on exposed organic phosphates. Organic phosphates are classified as either structural (phospholipids, nucleic acids) or energetic (corresponding to phosphoryl transfer activities). Extracellular phosphates promote a phenotypic shift in vascular smooth muscle and valvular interstitial cells towards an osteoblast gene expression pattern, which provokes the active phase of mineralization. A line of defense systems protects arterial and valvular tissue calcifications. Given the major roles of phosphate in soft tissue calcification, phosphate mimetics, and/or prevention of phosphate dissipation represent novel potential therapeutic approaches for arterial and valvular calcification.

Multiple Pathways for Pathological Calcification in the Human Body

Biomineralization of skeletal components (e.g., bone and teeth) is generally accepted to occur under strict cellular regulation, leading to mineral-organic composites with hierarchical structures and properties optimized for their designated function. Such cellular regulation includes promoting mineralization at desired sites as well as inhibiting mineralization in soft tissues and other undesirable locations. In contrast, pathological mineralization, with potentially harmful health effects, can occur as a result of tissue or metabolic abnormalities, disease, or implantation of certain biomaterials. This progress report defines mineralization pathway components and identifies the commonalities (and differences) between physiological (e.g., bone remodeling) and pathological calcification formation pathways, based, in part, upon the extent of cellular control within the system. These concepts are discussed in representative examples of calcium phosphate-based pathological mineralization in cancer (breast, thyroid, ovarian, and meningioma) and in cardiovascular disease. In-depth mechanistic understanding of pathological mineralization requires utilizing state-of-the-art materials science imaging and characterization techniques, focusing not only on the final deposits, but also on the earlier stages of crystal nucleation, growth, and aggregation. Such mechanistic understanding will further enable the use of pathological calcifications in diagnosis and prognosis, as well as possibly provide insights into preventative treatments for detrimental mineralization in disease.

Efficacy of Low-Pressure Inflation of Oversized Drug-Coated Balloon for Coronary Artery Disease

Objectives

This study sought to assess the efficacy of oversized drug-coated balloon (DCB) inflation at low pressure for the prevention of acute dissections and late restenosis.

Background

The major limitation of DCB coronary angioplasty is the occurrence of severe dissection after inflation of DCB.

Methods

Between 2014 and 2018, 273 consecutive patients were retrospectively studied. 191 lesions (154 patients) treated by oversized DCB inflation at low pressure (<4 atm, 2.4 ± 1.2 atm, DCB/artery ratio 1.14 ± 0.22; LP group) were compared with 135 lesions (119 patients) treated by the standard DCB technique (7.1 ± 2.2 atm, DCB/artery ratio 1.03 ± 0.16; SP group).

Results

Although the lesions in the LP group were more complex than those in the SP group (smaller reference diameter (2.38 mm vs. 2.57 mm, P=0.011), longer lesions (11.7 mm vs. 10.5 mm, P=0.10), and more frequent use of rotational atherectomy (45.0% vs. 28.1%, P=0.003), there was no significant difference in the NHLBI type of dissections between the two groups (11.5%, 12.0%, 5.2% vs. 12.6%, 12.6%, 2.2% in type A, B, and C, P=0.61), and no bailout stenting was required. In 125 well-matched lesion pairs after propensity score analysis, the cumulative incidence of target lesion revascularization at 3 years was 4.5% vs. 7.0%, respectively (P=0.60). Late lumen loss (−0.00 mm vs. −0.01 mm, P=0.94) and restenosis rates (7.4% vs. 7.1%, P=1.0) were similar in both of the groups.

Conclusion

The application of oversized DCB at low pressure is effective and feasible for preventing late restenosis comparative to the standard technique of DCB.

Segmentation of Coronary Calcified Plaque in Intravascular OCT Images Using a Two-Step Deep Learning Approach

We developed a fully automated, two-step deep learning approach for characterizing coronary calcified plaque in intravascular optical coherence tomography (IVOCT) images. First, major calcification lesions were detected from an entire pullback using a 3D convolutional neural network (CNN). Second, a SegNet deep learning model with the Tversky loss function was used to segment calcified plaques in the major calcification lesions. The fully connected conditional random field and the frame interpolation of the missing calcification frames were used to reduce classification errors. We trained/tested the networks on a large dataset comprising 8,231 clinical images from 68 patients with 68 vessels and 4,320 ex vivo cadaveric images from 4 hearts with 4 vessels. The 3D CNN model detected major calcifications with high sensitivity (97.7%), specificity (87.7%), and F1 score (0.922). Compared to the standard one-step approach, our two-step deep learning approach significantly improved sensitivity (from 77.5% to 86.2%), precision (from 73.5% to 75.8%), and F1 score (from 0.749 to 0.781). We investigated segmentation performance for varying numbers of training samples; at least 3,900 images were required to obtain stable segmentation results. We also found very small differences in calcification attributes (e.g., angle, thickness, and depth) and identical calcium scores on repetitive pullbacks, indicating excellent reproducibility. Applied to new clinical pullbacks, our method has implications for real-time treatment planning and imaging research.

Retrograde Pedal Access via Occluded Arteries in Endovascular Treatment of Critical Limb Ischemia

PURPOSE

To evaluate the feasibility and technical outcomes of retrograde access via occluded pedal arteries in endovascular treatment of critical limb ischemia (CLI) when the conventional antegrade approach fails.

MATERIALS AND METHODS

One hundred fifty-one patients with CLI (age 69 y ± 10.5; 116 men) who were not surgical candidates and were treated via retrograde pedal access between January 2016 and January 2018 were evaluated retrospectively. Seventy patients in whom retrograde access was performed through occluded arteries constituted the occluded group, and 81 patients who were treated via retrograde access from patent arteries constituted the nonoccluded group. Pedal access success, lesion crossing success, angiographic success, overall technical success, and procedure-related complications were evaluated and compared between groups.

RESULTS

Pedal access success (74 of 78 vs 83 of 87 attempts; P = .873) and lesion crossing success (64 of 78 vs 77 of 87 lesions; P = .340) were comparable between subgroups. Angiographic success (54 of 78 vs 77 of 87 lesions; P = .012) and overall technical success (48 of 70 vs 72 of 81 patients; P = .004) rates were lower in the occluded group. Procedure-related complications were similar between groups (P = .096).

CONCLUSIONS

Retrograde pedal access from occluded pedal arteries is a feasible option when an antegrade approach fails in endovascular treatment of CLI. Although it has lower technical success, its use enables angiosome-directed therapy and has the potential to improve the outcomes of the procedure.

Treatment of heavily calcified coronary artery stenosis using 3.5 mm peripheral intravascular lithotripsy balloon: case series

Background

Prevalence of coronary artery calcification is high among patients with advanced age, chronic kidney disease, and diabetes. Percutaneous coronary intervention of heavily calcified coronary artery remains a significant challenge for interventional cardiologists. Although there are several modalities available in treating calcified coronary arteries, lesion preparation of certain heavily calcified vessels remains inadequate prior to stent deployment and/or often associated with worse periprocedural adverse outcomes.

Case summary

We report feasibility and safety of 3.5 mm peripheral intravascular lithotripsy (IVL) for the treatment of severely calcified coronary stenosis in two patients after orbital atherectomy failed to debulk calcified plaque to enable stent deployment.

Discussion

Intravascular lithotripsy has recently emerged as a therapeutic option in treating calcified peripheral artery disease. However, coronary IVL is currently available only in a few centres in the USA. Studies are ongoing in the safety and efficacy of this technology in treating coronaries.