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The Calcium Lesion Modification Strategy (CLMS)

A step-by-step guide to modifying calcified lesions.

Calcific lesions: a growing risk

Over 30% of patients treated for PCI in the United States have some degree of calcium, a 31% increase over the last two decades.¹ Calcium can make it difficult to dilate the artery, leading to complications such as dissection, inadequate stent expansion, and stent malapposition. Patients with moderate to severe calcium have a significantly higher risk of complications, including:

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Dissection during balloon angioplasty or pre-dilation²

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Balloon dog boning²

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Prevention of stent delivery of target lesion³

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Stent under expansion or deformation⁴

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Insufficient drug penetration⁵

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Subsequent restenosis⁶

The solution: a simplified approach

The Calcium Lesion Modification Strategy is a simplified and highly effective approach to modifying calcific lesions. Based on proven research and clinical evidence, and vetted by expert interventional cardiologists, the CLMS is built on three key components shared by successful calcium algorithms:


Examine the lesion's severity and location using intravascular ultrasound (IVUS).



Utilize IVUS imaging to determine lesion morphology to help inform device selection.



Select the optimal therapy to effectively modify the lesion.


For optimal results, IVUS before, during, and after the procedure. View IVUS 123 Essentials, a guide to simplify IVUS workflow and optimize PCI outcomes.

The Calcium Lesion Modification Strategy (CLMS)⁷

A step-by-step guide.

Step by step graphic

CLMS Summary:

1. See if the device passes. If the device does not pass, treat with rotational atherectomy. If the device passes or the vessel is undilatable (1:1 size), begin to IVUS.

2. Conduct an IVUS pre-assessment. Measure: lesion location (ostial; establish lesion length and define landing zones), plaque morphology (arc: <270° vs. >270°; extent of disease: focal vs. diffuse), and vessel size MLD (<2mm vs. > 2mm).

3. Modify calcific lesion. If larger MLD device delivers eccentric arc <180°: modify calcium with a Cutting Balloon, if a smaller MLD ostial/diffuse preferred concentric arc >270°: modify calcium with Rotational Atherectomy; if a larger MLD ostial/focal preferred concentric arc >270°: modify calcium with Intravascular Lithotripsy.

Learn more about the Modern PCI approach

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ROTAPRO™ Rotational Atherectomy

Boost efficiency with the ROTAPRO System's cutting-edge ROTAWIRE™ Drive Guidewire, designed to help you optimize time and resources.

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WOLVERINE Cutting Balloon

WOLVERINE features a unique mechanism of action that enables precise vessel prep across a broad range of complex lesions. 

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Clinical data

Clinical Data

The evidence is clear: the use of IVUS, physiological assessment, and proper vessel prep can help to improve the success of PCI procedures, and reduce the risk of complications. 

Explore clinical data

1. Généreux, P. et al. J Am Coll Cardiol 2014 May;63(18):1845-1854.

2. Dehmer WJ, et al. Circulation. 2010 Jun 14;121(23):2547-55. doi: 10.1161/CIRCULATIONAHA.109.854509.

3. Gilutz H, et al. Cathet Cardiovasc Intervent. 2000;50:212-214.

4. Moussa I, et al. Circulation. 1997;96(1):128-136.

5. Nakano M, et al. Eur Heart J. 2013 Jul 3. Case study results are not predictive of results in other cases. Results in other cases may vary.

6. Nakano M, et al. Eur Heart J. 2013 Jul 3.

7. Adapted from Calcium Algorithm presented by Simon Walsh, MD, Boston

Case study results are not predictive of results in other cases. Results in other cases may vary.

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