Calcified coronary arteries remain one of the most difficult types of lesions to treat. The disease states that are predictive of coronary artery calcification, including advanced age, diabetes, smoking, chronic kidney disease, hypertension, hyperlipidemia, gender, ethnicity, and body mass index, are on the rise.1,2 Currently, calcification is found in an estimated 40% to 70% of imaged lesions,3 and severe calcification is present in 6% to 20% of coronary artery disease patients.4,5 These rates are expected to increase over the next 10 years.

It is challenging to achieve optimal results in severely calcified lesions with percutaneous coronary intervention, and it is difficult to completely dilate calcified plaques because the process may lead to underexpansion or malapposition.2,6,7 Calcified occlusions are prone to dissection during balloon angioplasty or predilatation.8 Delivering a stent to the desired location and calcium may result in stent distortion and insufficient drug penetration.2,9,10 Patients are often referred to bypass surgery due to the potential for adverse outcomes (both short and long term) related to treating severe coronary calcification.5,11-13 Fortunately, the availability and optimization of coronary atherectomy has allowed many patients to be treated successfully.

In 2013, the Diamondback 360® Orbital Atherectomy System (OAS) (Cardiovascular Systems, Inc.) was approved by the United States Food and Drug Administration for the treatment of de novo, severely calcified coronary artery lesions. In nearly a decade of clinical use, refinements in technique, including integration of imaging strategies along with a growing body of evidence and continuous innovation of the device platform, have enhanced outcomes with orbital atherectomy.14

The OAS uses a unique dual mechanism of action that combines differential sanding and pulsatile forces to sand intimal lesions and fracture medial calcium, thereby allowing optimal stent expansion.11,14 A single Diamondback® device treats vessels from 2.5 to 4.0 mm in diameter. Differential sanding protects soft tissue, while continuous flow of blood and saline during treatment reduces the risk of slow flow and no reflow events. Because of this, a single Diamondback device can safely treat a broad range of lesions with concentric, eccentric, and nodular calcium.

Diamondback utilization and therapy has evolved from early experience and clinical trials. The ORBIT I and ORBIT II clinical trials, as well as 11 major studies, including real-world multicenter studies enrolling approximately 1,000 patients,15,16 have constantly demonstrated the long-term safety and efficacy of coronary OAS for the treatment of severely calcified coronary lesions prior to stent delivery, with low procedural complication rates and low rates of revascularization through 3 years.11,14,15,17,18

The evidence supporting orbital atherectomy continues to expand. The prospective, randomized, multicenter ECLIPSE trial (NCT03108456) is currently enrolling. ECLIPSE will evaluate vessel preparation with Diamondback compared to conventional balloon angioplasty technique prior to drug-eluting stent implantation in severely calcified coronary artery lesions. Approximately 2,000 patients with severely calcified coronary lesions will be enrolled at approximately 150 sites in the United States.

This series of articles provides insight into the contemporary practice and use of the Diamondback® system.

1. Shaikh K, Nakanishi R, Kim N, Budoff MJ. Coronary artery calcification and ethnicity. J Cardiovasc Comput Tomogr. 2019;13:353-359. doi: 10.1016/j.jcct.2018.10.002

2. Cavusoglu E, Kini AS, Marmur JD, Sharma SK. Current status of rotational atherectomy. Catheter Cardiovasc Interv. 2004;62:485-498. doi: 10.1002/ccd.20081

3. Mintz GS, Popma JJ, Pichard AD, et al. Patterns of calcification in coronary artery disease. A statistical analysis of intravascular ultrasound and coronary angiography in 1155 lesions. Circulation. 1995;91:1959-1965. doi: 10.1161/01.cir.91.7.1959

4. Bourantas CV, Zhang YJ, Garg S, et al. 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. 2014;100:1158-1164. doi: 10.1136/heartjnl-2013-305180

5. Genereux P, Madhavan MV, Mintz GS, 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;63:1845-1854. doi: 10.1016/j.jacc.2014.01.034

6. Mosseri M, Satler LF, Pichard AD, Waksman R. Impact of vessel calcification on outcomes after coronary stenting. Cardiovasc Revasc Med. 2005;6:147-153. doi: 10.1016/j.carrev.2005.08.008

7. Moussa I, Di Mario C, Moses J, et al. Coronary stenting after rotational atherectomy in calcified and complex lesions. Angiographic and clinical follow-up results. Circulation. 1997;96:128-136. doi: 10.1161/01.cir.96.1.128

8. Fitzgerald PJ, Ports TA, Yock PG. Contribution of localized calcium deposits to dissection after angioplasty. An observational study using intravascular ultrasound. Circulation. 1992;86:64-70. doi: 10.1161/01.cir.86.1.64

9. Gilutz H, Weinstein JM, Ilia R. Repeated balloon rupture during coronary stenting due to a calcified lesion: an intravascular ultrasound study. Cathet Cardiovasc Intervent. 2000;50:212-214. doi: 10.1002/(sici)1522-726x(200006)50:2<212::aid-ccd15>3.0.co;2-t

10. Meraj PM, Shlofmitz E, Kaplan B, et al. Clinical outcomes of atherectomy prior to percutaneous coronary

intervention: a comparison of outcomes following rotational versus orbital atherectomy (COAP-PCI study). J Interv Cardiol. 2018;31:478-485.

11. Chambers JW, Feldman RL, Himmelstein SI, 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;7:510-518. doi: 10.1016/j.jcin.2014.01.158

12. Kaan K, Hakan S. Coronary artery bypass surgery. In: Coronary Artery Disease – Assessment, Surgery, Prevention. IntechOpen; November 18, 2015. doi: 10.5772/61404. Accessed May 7, 2021. https://www.intechopen.com/books/coronary-artery-disease-assessment-surgery-prevention/coronary-artery-bypass-surgery

13. Harvard Health Publishing. Should you have stenting or bypass surgery? Accessed April 30, 2021. https://www.health.harvard.edu/heart-health/should-you-have-stenting-or-bypass-surgery

14. Shlofmitz E, Martinsen BJ, Lee M, et al. Orbital atherectomy for the treatment of severely calcified coronary lesions: evidence, technique, and best practices. Expert Rev Med Devices. 2017:14:867-879. doi: 10.1080/17434440.2017.1384695

15. Lee M, Genereux P, Shlofmitz R, et al. Orbital atherectomy for treating de novo, severely calcified coronary lesions: 3-year results of the pivotal ORBIT II trial. Cardiovasc Revasc Med. 2017;18:261-264. doi: 10.1016/j.carrev.2017.01.011

16. Vinardell J, et al. Orbital atherectomy for treating de novo severely calcified coronary lesions: a tertiary center experience. J Am Coll Cardiol. 2020;76:B71.

17. Chambers JW, Diage T. Evaluation of the Diamondback 360 coronary orbital atherectomy system for treating de novo, severly calcified lesions. Expert Rev Med Devices. 2014;11:457-466. doi: 10.1586/17434440.2014.929493

18. Parikh K, Chandra P, Choksi N, et al. Safety and feasibility of orbital atherectomy for the treatment of calcified coronary lesions: the ORBIT I trial. Catheter Cardiovasc Interv. 2013;81:1134-1139. doi:10.1002/ccd.24700

Jeffrey W. Chambers, MD
Metropolitan Heart & Vascular Institute
Coon Rapids, Michigan
j.chambers@mhvi.com