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Andò et al. Vessel Plus 2023;7:15 https://dx.doi.org/10.20517/2574-1209.2023.26 Page 9 of 22

vessel which is structurally normal and therefore elastic; this contrasts sharply with what happens with the
balloon dilatation, which causes breakage of the plaque in the weakest point, with consequent intentional
dissections of the calcified area but also and especially of the non-calcified one. Indeed, dissections occur
less frequently with RA alone than when RA is followed by balloon angioplasty [65,66] . At rotational speeds
above 60,000 revolutions per minute (rpm), burr-to-vessel surface friction is virtually eliminated, thereby
reducing surface resistance, and allowing for unimpeded movement of the burr through the vessel. The
ablated plaque is reduced to micro-particles of 5-10 microns in diameter. These particles embolize distally in
the coronary artery but are generally small enough to pass through the microcirculation and ultimately be
phagocytosed by the reticuloendothelial system in the liver, the spleen, and the lungs.

Randomized evidence supporting Rotational Atherectomy
In a landmark randomized study of 240 patients with moderate to severe calcifications (Rotational
Atherectomy Prior to TAXUS Stent Treatment for Complex Native Coronary Artery Disease, ROTAXUS),
lesion preparation with RA resulted in greater procedural success than with predilatation with a standard
balloon (92.5% vs. 83.3%, P = 0.03), even if in terms of long-term results, both at 9 months and at 2 years, the
clinical effect was not significantly better and the incidence of MACE was in general quite relevant
regardless of the preparation strategy [59,67] . A comparison of a planned RA strategy vs. a bailout RA strategy
for severely calcified non-crossable or non-dilatable lesions demonstrated less procedural time, less use of
contrast agent and less incidence of coronary dissections requiring additional stenting . More recently, the
[68]
PREPARE-CALC study randomized 200 patients with severely calcified lesions to RA vs. angioplasty with
cutting/scoring balloon. The results demonstrate that RA is superior in terms of procedural success
compared to the cutting/scoring balloon strategy (98% vs. 81%) with shorter fluoroscopy times, but both
strategies guarantee an excellent result at 9 months in terms of angiographic late loss and new incidence of
revascularizations . These data were confirmed at 2-year follow-up and underscored the importance of
[69]
[70]
the combination of operators’ experience, intravascular imaging guidance and excellent DES performance
to obtain optimal long-term results in treating patients with severely calcified lesions. In summary, RA
demonstrated a higher procedural success rate in randomized trials, confirmed by the incidence of a
crossover rate to RA between 12% and 16% in the control arm.

Rotational Atherectomy procedure
The RA procedure is performed after administration of a standard dose of heparin (70-100 U/Kg), obtaining
an activated clotting time (ACT) ≥ 300 s. Recommendations for an optimal RA procedure include [62,63] :

• A guide catheter with high support stably positioned in the coronary ostium, for example, the Extra
Backup for the left coronary artery and the Amplatz Left for the right coronary artery;

• Stable positioning of the Rotawire in the distal segment of the vessel to be treated; the technical difficulties
in manipulating the Rotawire can be overcome by wiring the vessel with a conventional 0.014” guidewire
supported by an over-the-wire system (micro-catheter or balloon), which allows the conventional guide to
be exchanged with the Rotawire;

• One or two burrs of increasing diameter, while maintaining a burr/artery ratio ≤ 0.5-0.6, as larger diameter
[71]
burrs are more likely to cause complications ;
• Burr rotation speed between 140,000 and 180,000 rpm;