The clover sign. A predictor of optimal plaque modification after orbital atherectomy

A 72-year-old man with stable angina underwent coronary angiography, which revealed the presence of severe, calcified stenosis in the proximal left anterior descending coronary artery. Optical coherence tomography (OCT) confirmed the presence of a thick calcified lesion of eccentric and concentric distribution (figure 1, video 1 of the supplementary data). Orbital atherectomy (OA) using the Diamondback 360 system (Abbott Vascular, United States) was advanced initially at low speed (80 000 rpm) and, then, at high-speed backward ablation (120 000 rpm). Post-OA OCT revealed significant plaque modifications. Firstly, the sanding effect on the superficial calcium revealed a notable finding that could resemble a clover morphology (figure 2B,E, dashed red lines, asterisks). This “clover sign” consisted of 3 symmetrically distributed ablation pathways due to the combination of the antegrade and retrograde ablations that modify the plaque in different axes. Additionally, pulsatile forces of the OA induced deep calcium fractures (figure 2C). After predilation, a drug eluting stent was implanted with excellent results (figure 2D, F; video 2 of the supplementary data). Figure 1. Figure 2. We believe that this case adequately illustrates the effect of OA in calcified plaques and defines the specific features of the “clover sign”. In deep, concentric calcified plaques, OA shows its...