Impact of Coronary Calcium Morphology on Intravascular Lithotripsy

BACKGROUND: Coronary calcification negatively impacts optimal stenting. Intravascular lithotripsy (IVL) is a new calcium modification technique. AIMS: We aimed to assess the impact of different calcium morphologies on IVL efficacy. METHODS: This was a prospective, multicentre study (13 tertiary referral centres). Optical coherence tomography (OCT) was performed before and after IVL, and after stenting. OCT-defined calcium morphologies were concentric (mean calcium arc >180 degrees) and eccentric (mean calcium arc <= 180 degrees). The primary outcomes were angiographic success (residual stenosis <20%) and the presence of fracture by OCT in concentric versus eccentric lesions. RESULTS: Ninety patients were included with a total of 95 lesions: 47 concentric and 48 eccentric. The median number of pulses was 60 (p=1.00). Following IVL, the presence of fracture was not statistically different between groups (79.0% vs 66.0% for concentric vs eccentric; p=0.165). The number of fractures/lesion (4.2 +/- 4.4 vs 2.3 +/- 2.8; p=0.018) and >= 3 fractures/lesion (57.1% vs 34.0%; p=0.029) were more common in concentric lesions. Angiographic success was numerically but not statistically higher in the concentric group (87.0% vs 76.6%; p=0.196). By OCT, no differences were noted in final minimum lumen area (5.9 +/- 2.2 mm 2 vs 6.2 +/- 2.1 mm(2) ; p=0.570), minimum stent area (5.9 +/- 2.2 mm(2) vs 6.25 +/- 2.4 mm(2); p=0.483), minimum stent expansion (80.9 +/- 16.7% vs 78.2 +/- 19.8%), or stent expansion at the maximum calcium site (100.6 +/- 24.2% vs 95.8 +/- 27.3%) (p>0.05 for all comparisons of concentric vs eccentric, respectively). Calcified nodules were found in 29.5% of lesions; these were predominantly non-eruptive (57%). At the nodule site, dissection was more common than fracture with stent expansion of 103.6 +/- 27.2%. CONCLUSIONS: In this prospective, multicentre study, the effectiveness of IVL followed by stenting was not significantly affected by coronary calcium morphology.