Contemporary technologies to modify calcified plaque in coronary artery disease
Introduction
Since the initial development of percutaneous coronary intervention (PCI), progress in technology and evolved techniques enabled successful interventions in increasingly complex lesions and patient populations. With aging society, one of the more challenging obstacles are calcified coronary lesions. Despite culmination of knowledge and innovative devices, calcified lesions continue to pose a major challenge in PCI. Calcified lesions may impede stent delivery,1 limit balloon1 and stent expansion2 which result in lower minimal stent area (MSA), cause uneven drug distribution,3,4 and even hinder wire advancement. Lower MSA and stent under-expansion are associated with adverse outcomes, including target lesion and stent failure.5,6 Vessel calcification, even when associated with acceptable procedural success, is independently associated with increased target lesion revascularization (TLR) rates at follow-up7,8 and lower survival rates.8,9 In order to effectively manage such lesions, dedicated technologies have been developed. In the current review, we will discuss the available methods for atherectomy and the role of imaging in calcified lesions.
Section snippets
Currently available technologies to modify calcified plaque
Atherectomy, originally developed in the 1980s, 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. Existing technologies for atherectomy include rotational atherectomy,10, 11, 12 orbital atherectomy,13,14 excimer laser coronary atherectomy (ELCA),15, 16, 17 and directional atherectomy. A directional atherectomy device
Rotational atherectomy
The commercially available rotational atherectomy device is ROTAPRO or Rotablator (Boston Scientific) – a diamond-tipped brass burr rotating concentrically at 130,000–180,000 rounds per minute (rpm), driven by the energy of compressed gas. Atherectomy is achieved by mechanisms referred to as differential cutting and orthogonal displacement of friction. Differential cutting means that the high-speed ablation distinguishes plaque from the healthy vessel wall. The immobile and firm plaque remains
Orbital atherectomy
Orbital atherectomy is a method for reducing plaque burden with a mechanism aimed at minimizing vessel wall trauma. The commercially available device – Diamondback 360° Coronary Orbital Atherectomy System resembles rotational atherectomy in its ablative crown (equivalent to the burr) which is diamond coated and rotates in 80,000 and 120,000 rpm. It is shaped as an eccentric hump that orbits around the wire. In contrast to rotational atherectomy, the diameter of ablation increases with higher
Rotational versus orbital atherectomy outcomes
There is no prospective randomized study directly comparing rotational versus orbital atherectomy devices. In a propensity score matched cohort of overall 546 patients who underwent rotational versus orbital atherectomy, myocardial infarction occurred more often in the rotational atherectomy group, albeit overall safety outcomes did not differ between the groups.41 Of note, with orbital atherectomy, the initial lesion diameter was larger (lesion length was similar), perhaps due to sideway
Laser atherectomy
Laser atherectomy is another viable option for atherectomy. Excimer laser coronary atherectomy (ELCA) uses a xenon-chloride monochromatic compound. The optical fibers-containing coronary catheter carries 308 nm length (ultraviolet light spectrum) beams from the laser system that penetrate to a depth of 10–50 μm into the tissue. The laser beams are transmitted at a pulse frequency of 25–80 Hz and generate a fluence rate (the radiant power) of 30–80 mJ/mm. ELCA modifies plaque by 3 mechanisms
Intravascular lithotripsy
Although not an atherectomy device by definition, Shockwave Intravascular Lithotripsy (IVL) should be mentioned as it became available for the treatment of calcified coronary lesions initially in Europe and is now approved by the FDA in the United States. The concept of lithotripsy has been used to pulverize kidney stones using extracorporeal shockwaves without injuring healthy organs. In coronary lithotripsy, lesion modification is achieved by pulsatile mechanical energy delivered to calcified
Imaging of calcified plaque
Angiographically, calcium appears as areas of x-ray attenuation delineating the arterial course, especially before contrast injection. Moderate calcifications are defined as radiopacities noted during the cardiac cycle and severe calcifications are defined as radiopacities noticed without cardiac motion, involving both sides of the vessel wall.62 A recent study investigated the detection of calcium by angiography, intravascular ultrasound (IVUS), and optical coherence tomography (OCT) in 440
Practical approach for selecting devices to calcified plaque modification
Fig. 3 presents a suggested practical approach for selecting devices to modify calcified plaque. After a calcified plaque is identified by angiography, the lesion should be assessed with intracoronary imaging. If the intracoronary imaging device cannot cross, upfront rotational or orbital atherectomy needs to be considered. When assessing with intracoronary imaging, we need to identify the extent of calcium such as arc, thickness, and longitudinal length of calcium. As discussed above,
Conclusions
With aging population, interventional cardiologists encounter calcified coronary lesions more often and the importance of calcified plaque modification is increasing. Adequate calcified plaque modification is crucial to achieving adequate stent expansion, which can serve as a nidus for restenosis. Adjunctive intracoronary imaging devices are essential to properly identify the severity of calcium and select an appropriate device for lesion modification to achieve optimal results, especially in
Funding sources
None.
Disclosures
Dr. Latib has served on Advisory Boards for Medtronic, Boston Scientific, Philips, Canon, CorFlow and Abbott. Dr. Kobayashi has served as a consultant to ACIST Medical Systems Inc. and Abbott Vascular Inc. Dr. Bliagos has served on Advisory Boards for Boston Scientific. Dr. Rozenbaum and Dr. Takahashi have nothing to disclose.
References (71)
- et al.
Stent underexpansion and residual reference segment stenosis are related to stent thrombosis after sirolimus-eluting stent implantation: an intravascular ultrasound study
J Am Coll Cardiol
(2005) - et al.
Ischemic outcomes after coronary intervention of calcified vessels in acute coronary syndromes. Pooled analysis from the HORIZONS-AMI (harmonizing outcomes with revascularization and stents in acute myocardial infarction) and ACUITY (acute catheterization and urgent intervention triage strategy) TRIALS
J Am Coll Cardiol
(2014) - et al.
Impact of severe lesion calcification on clinical outcome of patients with stable angina, treated with newer generation permanent polymer-coated drug-eluting stents: a patient-level pooled analysis from TWENTE and DUTCH PEERS (TWENTE II)
Am Heart J
(2016) - et al.
High-speed rotational atherectomy before paclitaxel-eluting stent implantation in complex calcified coronary lesions: the randomized ROTAXUS (Rotational Atherectomy Prior to Taxus Stent Treatment for Complex Native Coronary Artery Disease) trial
JACC Cardiovasc Interv
(2013) - et al.
Pivotal trial to evaluate the safety and efficacy of the orbital atherectomy system in treating de novo, severely calcified coronary lesions (ORBIT II)
JACC Cardiovasc Interv
(2014) - et al.
Prospective, randomized, multicenter comparison of laser-facilitated balloon angioplasty versus stand-alone balloon angioplasty in patients with obstructive coronary artery disease. The Laser Angioplasty Versus Angioplasty (LAVA) Trial Investigators
J Am Coll Cardiol
(1997) - et al.
Early outcome of high energy laser (Excimer) facilitated coronary angioplasty ON hARD and complex calcified and balloOn-resistant coronary lesions: LEONARDO study
Cardiovasc Revasc Med
(2015) - et al.
Results of the study to determine rotablator and transluminal angioplasty strategy (STRATAS)
Am J Cardiol
(2001) - et al.
Comparison of frequency of complications with on-label versus off-label use of rotational atherectomy
Am J Cardiol
(2012) - et al.
Rotational atherectomy multicenter registry: acute results, complications and 6-month angiographic follow-up in 709 patients
J Am Coll Cardiol
(1994)
Current status of rotational atherectomy
JACC Cardiovasc Interv
Orbital atherectomy for treating de novo, severely calcified coronary lesions: 3-year results of the pivotal ORBIT II trial
Cardiovasc Revasc Med
Comparison of the efficacy and safety of orbital and rotational atherectomy in calcified narrowings in patients who underwent percutaneous coronary intervention
Am J Cardiol
Orbital atherectomy versus rotational atherectomy: a systematic review and meta-analysis
Int J Cardiol
Excimer laser LEsion modification to expand non-dilatable stents: the ELLEMENT registry
Cardiovasc Revasc Med
Effectiveness of excimer laser coronary angioplasty in acute myocardial infarction or in unstable angina pectoris
Am J Cardiol
Percutaneous excimer laser coronary angioplasty: results in the first consecutive 3,000 patients. The ELCA investigators
J Am Coll Cardiol
Randomised trial of excimer laser angioplasty versus balloon angioplasty for treatment of obstructive coronary artery disease
Lancet
Clinical success, complications and restenosis rates with excimer laser coronary angioplasty. The percutaneous excimer laser coronary angioplasty registry
Am J Cardiol
A prospective multicenter registry of laser therapy for degenerated saphenous vein graft stenosis: the COronary graft results following atherectomy with laser (CORAL) trial
Cardiovasc Revasc Med
Excimer laser angioplasty in acute myocardial infarction (the CARMEL multicenter trial)
Am J Cardiol
Excimer laser atherectomy in percutaneous coronary intervention: a contemporary review
Cardiovasc Revasc Med
Intravascular lithotripsy for treatment of severely calcified coronary artery disease
J Am Coll Cardiol
In vivo calcium detection by comparing optical coherence tomography, intravascular ultrasound, and angiography
JACC Cardiovasc Imaging
Intravascular ultrasound assessment of drug-eluting stent expansion
Am Heart J
Nonrandomized comparison of coronary stenting under intravascular ultrasound guidance of direct stenting without predilation versus conventional predilation with a semi-compliant balloon versus predilation with a new scoring balloon
Am J Cardiol
Intravascular ultrasound assessment of cobalt chromium versus stainless steel drug-eluting stent expansion
Am J Cardiol
Repeated balloon rupture during coronary stenting due to a calcified lesion: an intravascular ultrasound study
Catheter Cardiovasc Interv
Coronary stenting after rotational atherectomy in calcified and complex lesions. Angiographic and clinical follow-up results
Circulation
Human autopsy study of drug-eluting stents restenosis: histomorphological predictors and neointimal characteristics
Eur Heart J
Arterial paclitaxel distribution and deposition
Circ Res
Characteristics of early versus late in-stent restenosis in second-generation drug-eluting stents: an optical coherence tomography study
EuroIntervention
Prognostic implications of coronary calcification in patients with obstructive coronary artery disease treated by percutaneous coronary intervention: a patient-level pooled analysis of 7 contemporary stent trials
Heart
A randomized comparison of balloon angioplasty versus rotational atherectomy in complex coronary lesions (COBRA study)
Eur Heart J
Rotational atherectomy before paclitaxel-eluting stent implantation in complex calcified coronary lesions: two-year clinical outcome of the randomized ROTAXUS trial
Catheter Cardiovasc Interv
Cited by (8)
Intravascular lithotripsy for severe calcific internal carotid artery disease during transcarotid revascularization
2023, Annals of Vascular Surgery - Brief Reports and InnovationsIntravascular lithotripsy: A novel option for severe calcification of coronary artery
2024, Clinical CardiologyVascular calcification: from the perspective of crosstalk
2023, Molecular BiomedicineIntravascular Lithotripsy as a Novel Treatment Method for Calcified Unprotected Left Main Diseases—Comparison to Rotational Atherectomy—Short-Term Outcomes
2022, International Journal of Environmental Research and Public Health
- 1
Drs Rozenbaum and Dr. Takahashi contributed equally and are joint first authors.