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Page 14 of 22 Andò et al. Vessel Plus 2023;7:15 https://dx.doi.org/10.20517/2574-1209.2023.26

among the techniques for treating calcified coronary lesions.

Clinical evidence
The feasibility of the IVL technique in patients with severely calcified coronary artery lesions was assessed in
[108]
four single-arm prospective trials , which demonstrated the high procedural success and safety of the
technique, with a reasonably predictable incidence of adverse events. DISRUPT CAD I is the first-in-man
multicenter study on the use of coronary IVL before stent implantation in 60 patients with markedly
calcified lesions ≤ 32 mm in length . Clinical success (< 50% residual stenosis with no major in-hospital
[109]
events) was 95% due to the presence of 3 post-procedural non-Q myocardial infarctions. It is important to
note that no serious safety issues or technical complications such as coronary perforations, major
dissections, and slow flow/no-reflow or additional MACE events, including target vessel revascularizations,
were reported at 30 days. In the OCT sub-study, IVL was found to result in fractures in the calcific
component of the plaque in 43% of cases, with multiple circumferential fractures in > 25% of cases. In
particular, the effectiveness of the technique has been shown to be proportional to the calcium load, with a
higher rate of fractures in cases with a higher degree of calcification. The acute gain of luminal area after the
[110]
use of the IVL catheter was 2.1 mmq . DISRUPT CAD II is the prospective study following the
commercialization of the coronary IVL system in Europe. The study enrolled 120 patients with severe
calcific coronary artery disease treated with IVL and stent implantation. In this case, the primary outcome
was a composite of in-hospital MACE events (cardiac death, myocardial infarction, and target lesion
revascularization). The procedural success, in terms of effective treatment of the calcific lesion with IVL,
was 100%, and the fractures in the calcium were confirmed with OCT in 79% of cases. In all cases, the intra-
stent residual stenosis was less than 30%. No perforations or slow flow/no-reflow phenomena occurred in
any case and the incidence of MACE was 5.8% for the occurrence of 7 non-Q-wave myocardial
infarction . DISRUPT-CAD III was designed for regulatory approval of IVL and enrolled 431 patients
[111]
from the United States, the United Kingdom, France, and Germany. The primary endpoints of freedom
from MACE at 30 days (92.2%) for safety and procedural success for effectiveness (92.4%), respectively,
were both met. The mean calcified segment length (~50 mm), thickness (~1 mm), and angle (~300°) were
consistent with a high amount of CAC. OCT demonstrated calcium fractures after IVL in 67.4% of lesions
[112]
[113]
and minimal stent area was independent of demonstrable fractures on OCT . DISRUPT-CAD IV was
designed for regulatory approval of coronary IVL in Japan with a similar design and comparable results to
DISRUPT-CAD III.

ALGORITHM FOR TREATMENT OF SEVERELY CALCIFIC CORONARY LESIONS
Any operator should plan the strategy of treatment of a severely calcified coronary lesion after having
evaluated, as much accurately as possible, width of the circumference arc, longitudinal extension, depth, and
thickness of calcification in the coronary wall. All these observations can only be obtained using an imaging
[114]
technique, IVUS or OCT, to be chosen based on the operator’s experience and availability .

The impossibility of obtaining accurate imaging of the lesion because of the inability of the IVUS catheter to
cross the lesion or to obtain optimal blood clearance for OCT image acquisition should promptly direct the
operator towards an ablative technique such as atherectomy, or laser, if available. In the former case, aiming
to streamline the procedure, the guidewire that has crossed the lesion must be exchanged with the dedicated
guide of the atherectomy system, either RA or OA: this maneuver is greatly simplified by using a micro-
catheter. If even lesion crossing with the micro-catheter is not possible, the alternatives are either the direct
lesion wiring with the dedicated guidewire (Rotawire or Viperwire) of the atherectomy system (this is not a
straightforward maneuver, especially with the Rotawire because of the difficulties in manipulating it
through complex anatomies), or the use of the ELCA catheter on the guidewire which the crossing of the
lesion was obtained with.