Novel Micro Crown Orbital Atherectomy for Severe Lesion Calcification: Coronary Orbital Atherectomy System Study (COAST)

Initial experience with orbital atherectomy in a non-surgical center in Portugal

INTRODUCTION AND OBJECTIVES

Percutaneous coronary intervention (PCI) of severely calcified lesions is associated with a higher risk of procedural complications, suboptimal stent expansion, and in-stent restenosis. Lesion preparation with orbital atherectomy (OA) in severely calcified lesions has been shown to increase procedural success and decrease reintervention rates. In this study, we sought to report the procedural safety and efficacy of our initial experience with OA in a non-surgical center in Portugal.

METHODS

Patients with severely calcified coronary lesions who were treated with intended intravascular ultrasound (IVUS) guided OA were included in a prospective single-center registry. We evaluated several endpoints, including: debulking success, defined <50% residual stenosis severity after OA; procedural success, defined as stent implantation according to Optimal-IVUS PCI criteria; use of additional calcium debulking strategies; and procedural complications, including coronary no-reflow, dissection, perforation or side branch occlusion. Patients were followed up for 30 days to assess early cardiovascular or procedure-related death, myocardial infarction, myocardial injury and reintervention.

RESULTS

Between January 2023 and September 2023, 37 patients and 53 coronary arteries underwent OA. IVUS imaging was used in all cases. Debulking and procedural success were achieved in 90.5% and 97.3% of cases, respectively. In 26 (49.1%) lesions, additional calcium debulking techniques were needed. Procedural complications occurred in three cases and one patient died during hospitalization.

CONCLUSION

Our initial experience with OA for heavily calcified coronary lesions demonstrated high procedural success and overall favorable clinical outcomes.

Calcified coronary lesions: Imaging, prognosis, preparation and treatment state of the art review

Calcific coronary artery stenosis is a complex disease associated with adverse outcomes and suboptimal percutaneous treatment. Calcium plaque modification has emerged as a key strategy to tackle the issues that accompany calcific stenosis - namely reduced device deliverability, unpredictable lesion characteristics, and difficult dilatation. Atherectomy has traditionally been the treatment modality of choice for heavily calcified coronary stenoses. Contemporary technologies have emerged to aid with planning, preparation, and treatment of calcified coronary stenosis in an attempt to improve procedural success and long-term outcomes. In this State Of The Art Review, we synthesize the body of data surrounding the diagnosis, imaging, and treatment of calcific coronary disease, with a focus on i) intravascular imaging, ii) calcific lesion preparation, iii) treatment modalities including atherectomy, and iv) updated treatment algorithms for the management of calcified coronary stenosis.

Coronary Intravascular Lithotripsy

Coronary artery calcification is strongly associated with adverse cardiac events and can impede the success of percutaneous coronary intervention (PCI) due to challenges with delivery of equipment and expansion of stents. Current treatment modalities for mitigation of coronary calcification have limitations and inherent risk of complications. Coronary intravascular lithotripsy (IVL) is a novel technique to modify coronary artery calcification via acoustic pressure waves. IVL utilizes an easy-to-use device, which does not require a steep learning curve. Prospective studies have shown this technique to be safe and effective and can be used to adequately modify calcified coronary stenoses in preparation for PCI and stent deployment and optimization. IVL has unique features that can be used alone or as an adjunctive therapy to other available calcium modification tools. As compared to the currently established modalities of calcium modification, IVL has the potential to facilitate successful PCI with fewer serious procedural complications. In this review article, we discuss the importance of coronary artery calcification, the role of IVL, its mechanism, the current clinical data behind its use and future directions. Overall, coronary IVL is a promising technology for the treatment of severely calcified coronary stenoses, with a need for, long-term clinical outcome data of IVL-facilitated PCI.

Systematic Review of the Efficacy of Orbital Atherectomy in Improving the Outcome of Percutaneous Corornary Intervention in People With Diabetes

The optimal approach to deal with severe coronary artery calcification (CAC) in people with diabetes remains ill-defined. People with diabetes have a significant risk of developing severe vessel calcification and coronary artery disease (CAD). CAD is the leading cause of death in people with diabetes. Individuals with diabetes mainly present with severe multivessel stenosis, diffuse coronary calcification, and severe atherosclerosis, which are poor prognostic factors of revascularization procedures. Studies have shown that the revascularization of arteries in people with diabetes often results in worse outcomes than in people without diabetes. Coronary artery bypass grafting (CABG) has been recommended as the standard of care for people with DM and complex anatomic diseases, including left main CAD. However, percutaneous coronary intervention (PCI) is more acceptable to patients in clinical practice because of decreased trauma and rapid recovery. Severe CAC has traditionally been challenging for PCI and a frequent indication for surgical revascularization. This study aims to determine the effectiveness of orbital atherectomy (OA) in improving PCI outcomes in patients with diabetes and identify possible adverse effects that preclude its use.  The study is reported according to PRISMA and analyzed according to Cochrane guidelines on synthesis without meta-analysis. A comprehensive literature search of EMBASE, Scopus, Web of Science, Cochrane Library, CINAHL, and MEDLINE was conducted for studies that utilized OA before PCI in people with diabetes. A reference list of the eligible articles was also screened. A narrative synthesis was done by representing the data on the effect direction plot, followed by vote counting. Eighteen studies were included in the analysis. Success rate/successful stent delivery was >90%, while freedom from angiographic complication and major adverse cardiovascular and cerebrovascular events (MACCE) were both >80% on the effect direction plot for people with diabetes and those without diabetes. People with diabetes had low event rates similar to those without diabetes. OA appears to be a viable treatment approach for people with diabetes. However, RCTs with a longer duration of follow-up are required to establish the appropriate treatment strategy for severe CAC in people with diabetes.

Early experience of intravascular lithotripsy in unprotected calcified left main coronary artery disease

BACKGROUND

Treatment of unprotected severely calcified left main coronary artery (LMCA) disease is a complex interventional procedure. Intravascular lithotripsy (IVL) and rotational atherectomy (RA) are safe and effective methods of treating coronary calcification in the non-LMCA setting. This retrospective analysis assessed the feasibility of IVL versus RA in unprotected LMCA disease.

METHODS

We analyzed IVL and RA procedures performed at a large tertiary hospital in the Northeast of England from January 1, 2019 to April 31, 2022. Major safety and efficacy endpoints were procedural and angiographic success, defined by stent delivery with <50 % residual stenosis and without clinical or angiographic complications, respectively. Another important clinical endpoint was the composite of major adverse cardiac events (MACE) at 1 year.

RESULTS

From 242 patients, 44 had LMCA IVL, 81 had LMCA RA and 117 had non-LMCA IVL. Patients with LMCA disease were older and more likely to have aortic stenosis. IVL was a second-line or bailout technique in 86.4 % LMCA and 92.2 % non-LMCA cases. Procedural and angiographic success rates were ≥ 84 % across all groups (p > 0.05). In 3 LMCA IVL and 3 LMCA RA cases arrhythmias and cardiac tamponade complicated the procedures respectively. At 1 year, MACE occurred in 10/44 (22.7 %) LMCA IVL, 16/81 (19.8 %) LMCA RA and 25/117 (21.4 %) cases (p > 0.05).

CONCLUSION

In our single center retrospective analysis, IVL is feasible in unprotected calcified LMCA as a second-line and third-line adjuvant calcium modification technique. Its use in unprotected calcified LMCA disease should be formalized with the undertaking of large randomized controlled trials.

Drug-coated balloon strategy following orbital atherectomy for calcified coronary artery compared with drug-eluting stent: One-year outcomes and optical coherence tomography assessment

BACKGROUND

Percutaneous coronary intervention (PCI) for calcified coronary artery remains challenging in the drug-eluting stent (DES) era. While recent studies reported the efficacy of orbital atherectomy (OA) combined with DES for calcified lesion, the effectiveness of drug-coated balloon (DCB) following OA has not been fully elucidated.

METHODS

Between June 2018 and June 2021, 135 patients who received PCI for calcified de novo coronary lesions with OA were enrolled and divided into two groups; OA followed by DCB (n = 43) if the target lesion achieved acceptable preparation, or second- or third-generation DESs (n = 92) if the target lesion showed suboptimal preparation between June 2018 and June 2021. All patients underwent PCI with optical coherence tomography (OCT) imaging. The primary endpoint was 1-year major adverse cardiac event (MACE), that was a composite of cardiac death, nonfatal myocardial infarction, or target lesion revascularization.

RESULTS

Mean age was 73 years and 82% was male. In OCT analysis, maximum calcium plaque was thicker (median: 1050 µm [interquartile range (IQR): 945-1175 µm] vs. 960 µm [808-1100 µm], p = 0.017), calcification arc tended to larger (median: 265° [IQR: 209-360°] vs. 222° [162-305°], p = 0.058) in patients with DCB than in DES, and the postprocedure minimum lumen area was smaller in DCB compared with minimum stent area in DES (median: 3.83 mm² [IQR: 3.30-4.52 mm² ] vs. 4.86 mm² [4.05-5.82 mm² ], p < 0.001). However, 1 year MACE free rate was not significantly different between 2 groups (90.3% in DCB vs. 96.6% in DES, log-rank p = 0.136). In the subgroup analysis of 14 patients who underwent follow-up OCT imaging, late lumen area loss was lower in patients with DCB than DES, despite lower lesion expansion rate in DCB than DES.

CONCLUSIONS

In calcified coronary artery disease, DCB alone strategy (if acceptable lesion preparation was performed with OA) was feasible compared with DES following OA with respect to 1-year clinical outcomes. Our finding indicated using DCB with OA might be reduce late lumen area loss for severe calcified lesion.

Early experience with coronary debulking devices in a newcomer facility after introducing revised facility criteria in Japan

Coronary debulking devices are essential in obtaining optimal results in percutaneous coronary intervention (PCI) for severely calcified lesions. However, since the introduction of these devices in Japan, the presence of full-time cardiovascular surgeons in their own facilities has been an essential condition (on-site surgical back-up) as the facility criteria for their use. The criteria were revised in April 2020, making their implementation possible at our hospital. Between May 2020 and January 2022, we administered PCIs using rotational atherectomy (RA) for 33 lesions in 28 patients and orbital atherectomy system (OAS) for 36 lesions in 27 patients. The most preferred strategy in our hospital is OAS via the distal radial approach using a 6Fr Glide sheath or RA via the femoral approach using a 7Fr sheath. The percentages of usable imaging modality as an initial device without lesion modification were 57.1 and 66.7% in the RA and OAS groups, respectively. In the RA procedure, 1.5- and 2.0-mm Rota burrs were more frequently adopted for the initial and second sessions, respectively. In the OAS procedure, the debulking was always initiated at a low speed. Nineteen of the 27 patients underwent additional high-speed debulking. Pre-procedural quantitative coronary angiographic analysis revealed that the minimal lumen diameter was significantly smaller in the RA than in the OAS group. Debulking procedures were successful in all patients excluding two instances of procedure-related complications in the RA group, one of which was coronary perforation safely treated via covered stent deployment without any resulting hemodynamic instability. Our early experience with coronary debulking devices with off-site surgical back-up clearly reveals the safety and feasibility of this procedure in a newcomer facility.

Calcium Modification in Percutaneous Coronary Interventions

Moderate-severe calcification increases procedural complications and impairs long-term prognosis post-PCI. Intravascular imaging (particularly optical coherence tomography [OCT]) is useful in guiding the treatment of calcified lesions. Weighted sum of calcium length, arc, and thickness on OCT can predict adequate stent expansion, identifying when atherectomy is required. With intravascular imaging guidance, various techniques alone or in combination may be used in an algorithmic fashion to modify calcified lesions. Calcium fracture by balloon angioplasty, cutting/scoring balloons, intravascular lithotripsy (IVL), atherectomy devices, or Excimer laser improves stent expansion. Intravascular imaging is essential in the treatment of in-stent restenosis when luminal and/or abluminal peri-strut calcium is present.

Association between coronary artery calcium score and in-stent restenosis after drug-eluting stent implantation

BACKGROUND

Coronary artery calcium (CAC) is a modifiable contributor of in-stent restenosis (ISR), but quantitative analyses using a noninvasive approach are limited. We aimed to investigate the associations between CAC score derived from ECG-gated coronary computed tomography angiography (CCTA) or non-gated non-contrast chest computed tomography (NCCT) and ISR.

METHODS

We included 368 lesions in 194 patients with coronary drug-eluting stent implantations in final analyses. CAC was quantified using the Agatston score. Primary endpoint was ISR, defined as lumen diameter stenosis over 50% at the stent segment or its proximal or distal edges (5-mm segments adjacent to the stent), at angiographic follow-up.

RESULTS

The CAC scores in either CCTA/2.5 mm group (r = 0.7702; P < 0.0001) or NCCT/5 mm group (r = 0.7105; P < 0.0001) were both correlated with in-stent diameter stenosis. The receiver-operating characteristic curve analysis identified a CAC score >245 in CCTA/2.5 mm group as the optimal ISR cutoff (sensitivity, 60.0%; specificity, 83.7%; area under the curve, 0.744; P < 0.001), and >209 in NCCT/5 mm group (sensitivity, 46.7%; specificity, 91.9%; area under the curve, 0.704; P < 0.001). Multivariable logistic regression models indicated a CAC score >245 in CCTA/2.5 mm group and >209 in NCCT/5 mm group independently associated with an 8.46- and 21.89-fold increase in ISR, respectively (all P < 0.01).

CONCLUSIONS

Either a CAC score >245 in CCTA/2.5 mm or >209 in NCCT/5 mm was significantly associated with increased risk in ISR.

Incidence and characteristics of incomplete stent apposition in calcified lesions: An optical coherence tomography study

BACKGROUND

Persistent or late acquired incomplete stent apposition (ISA) may be associated with late or very late stent thrombosis following drug-eluting stent implantation. Presence of calcium at the target lesion may increase the risk of ISA even after rotational atherectomy (RA) followed by stenting with high pressure balloon inflation. The aim of this study is to examine the incidence and characteristics of ISA in heavily calcified lesions.

METHODS

A total of 52 heavily calcified coronary artery lesions requiring RA plus stenting were selected and studied. After successful ablation followed by stent implantation, optical coherence tomography (OCT) was performed to assess stent expansion and apposition. Presence or absence of ISA was examined and maximal stent strut to vessel wall distance (max SV distance) was measured. In lesions with repeated OCT at follow-up, serial changes in ISA were investigated.

RESULTS

ISA was documented in 51 of 52 (98%) lesions. Mean max SV distance was 713 ± 371 μm. In lesions with serial OCT images (n = 11), max SV distance decreased significantly (692.1 ± 420.2 to 462.5 ± 387.0 μm, P < 0.01) but persisted in all but 2 lesions (82%).

CONCLUSIONS

ISA is frequently documented in heavily calcified lesions requiring RA. Significant ISA still persisted with minimal improvement in SV distance at follow-up. Prognostic impact of the persistent ISA in such calcified lesions needs further investigations.

Percutaneous management of calcified coronary arteries - review of atherectomy and lithotripsy devices and why it is important

PURPOSE OF REVIEW

Coronary artery calcification (CAC) predisposes to suboptimal revascularization outcomes after percutaneous coronary intervention (PCI). Despite the availability of several plaque modification devices, their rates of use remain low despite the prevalence of CAC encountered in clinical practice. It is important to understand how each device can be utilized in clinical practice in order to improve outcomes after PCI.

RECENT FINDINGS

This article summarizes the most recent clinical evidence for each plaque modification device. Although rotational atherectomy is the most frequently used device for plaque modification, the use of orbital atherectomy (OA) has been increasing. Balloon-based strategies including recent studies evaluating a novel intravascular lithotripsy balloon have shed light on the benefits of nonablative devices in modifying CAC during PCI.

SUMMARY

CAC poses significant technical challenges in achieving optimal stent results. Several intracoronary plaque modification devices are currently available and understanding the technical aspects, indications and contraindications to the use of each device is essential. Although rotational and OA are most commonly used, laser atherectomy and balloon-based devices may offer an advantage in certain lesion subsets.

Evaluation of the Safety and Efficacy of Coronary Intravascular Lithotripsy for Treatment of Severely Calcified Coronary Stenoses: Evidence From the Serial Disrupt CAD Trials

Background: Previous understanding holds that rotational atherectomy and modified balloons remain the default strategy for severely calcified coronary stenoses. In recent years, coronary intravascular lithotripsy (IVL) provides new ideas. This study was conducted to evaluate the safety and efficacy of IVL for the treatment of severely calcified coronary stenoses. Methods: The serial Disrupt CAD trials (Disrupt CAD I, Disrupt CAD II, Disrupt CAD III, and Disrupt CAD IV) were included in this study. The safety endpoint was freedom from major adverse cardiovascular events (MACE) in hospital, at 30 days, and at 6 months following the index procedure. The efficacy endpoints included procedural success and angiographic success. Optical coherence tomography (OCT) was used to evaluate the mechanism of action of IVL quantifying the coronary artery calcification (CAC) characteristics and calcium plaque fracture. Results: We enrolled a total of 628 patients with a mean age of 71.8 years, 77.1% males. In these patients, the left anterior descending artery and right coronary artery were the most vulnerable vessels. The diameter stenosis was 64.6 ± 11.6% and the lesion length was 24.2 ± 11.4 mm. IVL had a favorable efficacy (93.0% procedural success, 97.5% angiographic success, and 100.0% stent delivery). Among the 628 patients, 568, 568, and 60 reported MACE endpoints in hospital, at 30 days, and at 6 months, respectively. The results showed that 528, 514, and 55 patients were free from MACE in hospital, at 30 days, and at 6 months, respectively. OCT measurements demonstrated that calcium fracture was the underlying mechanism of action for coronary IVL. Conclusions: IVL is safe and efficient for severely calcified coronary stenoses, and, importantly, calcium fracture facilitated increased vessel compliance and favorable stent expansion.

Contemporary technologies to modify calcified plaque in coronary artery disease

With aging society, one of the more challenging obstacles in percutaneous coronary interventions are calcified coronary lesions. Calcified lesions may impede stent delivery, limit balloon and stent expansion, cause uneven drug distribution, and hinder wire advancement. Even in the setting of acceptable procedural success, vessel calcification is independently associated with increased target lesion revascularization rates at follow-up and lower survival rates. In order to effectively manage such lesions, dedicated technologies have been developed. Atherectomy aims at excising tissue and debulking plaques, as well as compressing and reshaping the atheroma, generally referred to as lesion preparation that enables further balloon and/or stent expansion in contemporary clinical practice. In the current review, we will discuss the available methods for atherectomy, including rotational, orbital, and excimer laser coronary atherectomy, as well as intravascular lithotripsy. In addition, we will review the role of imaging in calcified lesions.

Therapeutic Approach to Calcified Coronary Lesions: Disruptive Technologies

PURPOSE OF REVIEW

Moderate or severe calcification is present in approximately one third of coronary lesions in patients with stable ischemic heart disease and acute coronary syndromes and portends unfavorable procedural results and long-term outcomes. In this review, we provide an overview on the state-of-the-art in evaluation and treatment of calcified coronary lesions.

RECENT FINDINGS

Intravascular imaging (intravascular ultrasound or optical coherence tomography) can guide percutaneous coronary intervention of severely calcified lesions. New technologies such as orbital atherectomy and intravascular lithotripsy have significantly expanded the range of available techniques to effectively modify coronary calcium and facilitate stent expansion. Calcium fracture improves lesion compliance and is essential to optimize stent implantation. Intravascular imaging allows for detailed assessment of patterns and severity of coronary calcium that are integrated into scoring systems to predict stent expansion, identifying which lesions require atherectomy for lesion modification. Guided by intravascular imaging, older technologies such as rotational atherectomy and excimer laser can be incorporated with newer technologies such as orbital atherectomy and intravascular lithotripsy into an algorithmic approach for the safe and effective treatment of patients with heavily calcified coronary lesions.

Short term outcomes of rotational atherectomy versus orbital atherectomy in patients undergoing complex percutaneous coronary intervention: a systematic review and meta-analysis

OBJECTIVE

Coronary artery calcification (CAC) is one of the paramount hurdles for percutaneous coronary intervention (PCI) since it impedes stent delivery and complete expansion. This study intended to evaluate the short-term clinical and procedural outcomes comparing rotational atherectomy (RA) and orbital atherectomy (OA) in patients with heavily calcified coronary lesions undergoing PCI. Design: This systematic review and meta-analysis included all head-to-head published comparisons of coronary RA versus OA. Procedural endpoints and post-procedural clinical outcomes (30 days/in-hospital), were compared. RevMan 5.3 software was used for data analysis. Results: Seven retrospective observational investigations with a total of 4623 patients, including 3203 patients in the RA group and 1420 patients in the OA group, were incorporated. Compared with OA, the RA group was associated with a higher incidence of myocardial infarction at short-term follow-up (OR: 1.56, 95% CI: 1.07-2.29, p = .02, I² = 0%). No difference was noted among other short-term post-procedural clinical outcomes including all-cause mortality, target vessel revascularization, or major adverse cardiac events. Among procedural complications, RA was associated with reduced coronary artery dissection and arterial perforation. Increased fluoroscopy time was observed in the RA cohort as compared with OA (MD: 4.78, 95% CI: 2.25-7.30, p = .0002, I² = 80%). Conclusion: RA was associated with fewer vascular complications, but at a cost of higher incidence of myocardial infarction and higher fluoroscopy time compared with OA, at short term follow-up. OA is a safe and effective alternative for the management of CAC.