Intravascular lithotripsy during percutaneous coronary intervention for calcified coronary lesions: analysis of patient and procedural characteristics and clinical outcomes
Authors: Leung J , Pender P , French J , Leung D , Mussap C , Asrress K , Taylor D , Naguib Badie T , Kadappu K , Gibbs O , Kachwalla K , Nguyen P , Hopkins A , Lo S 
Published: February 2022

Abstract

Funding Acknowledgements
Type of funding sources: None.
Background/Introduction
Coronary artery calcification is frequently encountered during percutaneous coronary intervention (PCI). It can reduce PCI success and increase intra-procedural and post-procedural complications, including stent embolization, under-expansion and mal-apposition. Intravascular lithotripsy (IVL) is a new tool developed to treat calcified coronary lesions.

Purpose
Retrospective analysis of all cases of intravascular lithotripsy performed within our local health district to examine patient and procedural characteristics and clinical outcomes.

Methods
All patients undergoing PCI with intravascular lithotripsy between September 2019-August 2021 within our local health district were analysed. Patient and procedural characteristics and clinical outcomes were recorded.

Results
67 patients (50 men) were included with mean age 71.4 ± 8.7years. Risk factors prevalence included smoking (34%), hypertension (82%), dyslipidaemia (69%) and diabetes (46%). Trans-radial artery access was used in 38 patients (57%). IVL was performed most commonly in the left anterior descending artery (52%),[Figure 1]. IVL was utilised in 9 chronic total occlusions and 12 bifurcation lesions. Intracoronary (IC) imaging was performed in 59 patients (88%), intravascular ultrasound in 41(61%) and optical coherence tomography in 18 (27%). 41 (69%) patients had imaging performed pre and post IVL and post PCI. IC imaging identified 14 cases with 270º calcification arc and 45 cases with 360º arc. Nine cases (13.4%) required rotational atherectomy prior to IVL (most commonly 1.75mm burr). Mean reference vessel diameter was 3.2 ± 0.3mm. Mean lesion length was 36.3 ± 16.5mm. Mean pre-PCI stenosis was 85.5 ± 10.8%. Drug eluting stents were successfully deployed in 57 cases (85%), 10 had balloon angioplasty alone. Mean stent length was 39.2 ± 17.8mm. Mean post-PCI stenosis was 4.5 ± 13.3% (median 0%). Figure 2 shows a statistically significant increase in minimum lumen diameter and minimum lumen area post-IVL and minimal-stent-area (MSA) post-PCI. Mean stent expansion was 83%. Mean screening time 35.8 ± 17.8 minutes with mean contrast used 207.3 ± 78.7mL. No sustained arrhythmias or side-branch loss occurred. Vessel rupture was recorded in one patient necessitating urgent cardiac surgery (due to oversized balloon) and in 4 cases the IVL balloon could not cross the lesion.

Conclusion
Our experience shows that IVL is safe and effective and facilitates stent delivery and expansion. Intracoronary imaging is important to determine the need for calcium modification and evaluate its success prior to stent delivery and to confirm optimised stent expansion. Abstract Figure. Breakdown of PCI Artery Abstract Figure. IC Dimensions Pre/Post IVL/Post PCI