1.2 Plaque Modification: When to Apply Ablative vs Disruptive Therapies

These proceedings summarize the educational activity of the 16th Biennial Meeting of the International Andreas Gruentzig Society held January 31-February 3, 2022 in Punta Cana, Dominican Republic

Faculty Disclosures     Vendor Acknowledgments

2022 IAGS Summary Document

Statement of the problem or issue

In the beginning we only had balloons available to modify plaque, that is, plain old balloon angioplasty (POBA). In those days, plaque-modification options were simple: smaller balloons were used to “predilate,” and larger, noncompliant balloons were used to “postdilate.” Starting in the 1990s, the era of “new devices” began. We had directional atherectomy, rotational atherectomy, cutting balloons, and excimer laser, all of which were developed in that era. Some of these survived into the 2000s. Currently, we have rotational atherectomy (RA), orbital atherectomy, cutting balloon, excimer laser, and the newest technology, shockwave lithotripsy. We can group these devices into classes. The Ablative Class includes both rotational and orbital atherectomy devices. The Disruptive Class includes cutting balloons and shockwave lithotripsy. The excimer laser overlaps these classes because it has both ablative as well as disruptive actions (Table 1).

We have learned through experience that these devices are rarely the primary treatment modality, but instead are used as adjuncts to another primary treatment, which usually is a stent, and more specifically, a drug-eluting stent.

Gaps in knowledge

We don’t know exactly what the adjunctive role of these devices should be. We are trying to understand when and how plaque modification with these devices should be done in order to achieve a successful immediate procedure with a durable, long-lasting result. Situations where plaque modification techniques might be considered include the following: moderate to heavy calcification, provisional vs direct lesion approaches, and when unfavorable angiographic features are present, for example, when there is marked angulation or severe tortuosity in an artery. Of course, failure to cross a lesion, or failure to predilate the lesion sufficiently to permit passage of the primary treatment catheter, are examples of situations where additional, adjunctive therapies are needed (Table 2).

Another gap area in our knowledge is the matching of devices to situations. Some situations appear to favor one class of device, while other situations appear to favor another class (Table 3).

While we know there are many situations where one or more of these unfavorable conditions listed in Table 2 exist, we are still lacking strong evidence on best practices.

Possible solutions and future directions

The newest technology added to our armamentarium is the shockwave lithotripsy device, manufactured by Shockwave Medical. It was approved for peripheral artery use in 2016, and approved for coronary use in February 2021.¹ The device uses bursts of energy to emit 50 atm pressure waves that create microfractures in calcified plaque. It appears to be simple, safe, effective, and also expensive. The question of shockwave lithotripsy expense brings up the concept of “value.” Is there a valid “value” equation for use of these devices, and if so, in what situations? The larger question, though, still remains the same: what are the respective roles of these adjunctive devices? Only further research will reveal answers.

Reference

1. Liang B, Gu N. Evaluation of the safety and efficacy of coronary intravascular lithotripsy for treatment of severely calcified coronary stenoses: evidence from the Serial Disrupt CAD trials. Front Cardiovasc Med. 2021;8:724481. eCollection 2021. doi:10.3389/fcvm.2021.724481