Background: Severely calcified coronary lesions provide a particular challenge for percutaneous coronary intervention (PCI). Intracoronary lithoplasty has been recently introduced in clinical practice and provides the unique possibility to fracture coronary calcifications before stent placement, also in deeper vessel layers. Rotablation is the current gold-standard treatment for severely calcified lesions, but it is usually associated with higher procedural risks and is only able to modify calcified plaques located close to the vessel lumen.

Purpose: The aim of this ongoing study is to compare the effects of rotablation and coronary lithoplasty on severely calcified coronary lesions in a randomized patient cohort using optical coherence tomography (OCT). 

Methods: Coronary lithoplasty or rotablation were performed randomly in 21 patients with severe lesion calcification. OCT was performed pre-procedurally as well as immediately post-procedurally to compare lumen/stent areas, plaque mass, and vessel wall configuration. Patient clinical data and procedural characteristics were collected additionally.

Results: The mean patient age was 77±11 years. All patients were symptomatic with stable angina. Pre-procedural minimal lumen area was 1.82±0.66 mm² and mean lumen area was 4.27±1.90 mm². Mean plaque volume before interventional treatment was 22.78±10.44 mm³ with an average angle of 149±63°. Mean and minimum stent areas were larger after lithoplasty than after rotablation (11.53±2.73 mm² vs. 8.44±3.07 mm²; p=0.12 and 7.66±2.02 mm²vs. 5.82±2.25 mm²; p=0.22). Fractures of the calcified plaque extending into the vessel media were observed in all cases of lithoplasty but in no case where rotablation was performed (10/10 vs. 0/11; p<0,001). Mean lumen gain was larger after lithoplasty than after rotablation (7.27±3.22 mm² vs. 4.02±2.78 mm²; p=0.07). There were no differences in stent symmetry (eccentricity index after lithoplasty 0.63±0.15 vs. rotablation 0.65±0.18; p=0.92) or strut malapposition (mean malapposition area 0.69±0.55 mm² vs. 0.65±0.43 mm²; p=0.88) between lithoplasty and rotablation. There were no periprocedural adverse events.

Conclusion: Coronary lithoplasty is a promising treatment option for severely calcified coronary lesions and seems to be associated with a larger mean and minimum stent area as compared with rotablation. This might be caused by the induction of fractures of the calcified plaque in deeper vessel layers.

This study is funded by the Else Kröner-Fresenius-Stiftung