Abstract
BACKGROUND: Calcified coronary lesions impede stent expansion and are associated with poor outcomes after percutaneous coronary interventions. Intravascular lithotripsy (IVL) has emerged as a safe and effective pretreatment to optimise stent implantation. AIMS: This study assesses the LithiX lithotripsy device, which uses the Hertz contact (HC) mechanism to fragment calcium while minimising injury to surrounding soft tissue, without requiring an external energy source. METHODS: The multicentre, prospective PINNACLE-I clinical trial enrolled patients with up to two moderately to severely calcified de novo lesions. The primary endpoints were <50% residual stenosis without in-hospital major adverse cardiovascular events (MACE) and the 30-day MACE rate. Clinical events were assessed up to 6 months. RESULTS: Sixty patients with 63 lesions were treated with successful delivery and use of the HC-IVL catheter and a median procedure time of 59.5 min (interquartile range: 40.5-76.0). The primary endpoint was achieved in 98.3%. All patients had residual stenosis <30% after stent placement. The 30-day MACE rate was 1.7%, due to 1 periprocedural target vessel non-Q-wave myocardial infarction. There were no cardiovascular deaths, no definite or probable stent thromboses, nor any device-related events up to 6 months of follow-up. The optical coherence tomography substudy in 32 subjects identified a wide range of calcium morphologies, including calcium arcs of 96-360° and calcified nodules. Following HC-IVL, calcium fractures were achieved in 90.6% of lesions, and the mean fracture depth was 0.81±0.33 mm. Stent expansion at the minimum stent area site was 96.7±25.5%. CONCLUSIONS: PINNACLE-I demonstrated the feasibility, safety, and efficacy of the novel HC-IVL to fracture calcified lesions and achieve optimal stent expansion in a broad range of calcium morphologies.