INITIAL EXPERIENCE WITH THE USE OF INTRAVASCULAR LITHOTRIPSY FOR CORONARY CALCIUM MODIFICATION

BACKGROUND The treatment of calcified coronary arteries remains challenging. Shockwave intravascular lithotripsy (IVL) has recently been approved by Health Canada. It is emerging as a safe and effective coronary calcium modification modality. In this study, we report our experience with introducing this technology at our centre. METHODS AND RESULTS Between January 2020 and April 2021, we prospectively identified all consecutive cases, where IVL was used. Demographic, clinical and procedural data including complications were collected in a dedicated electronic database. Four interventional cardiologists treated 22 patients (31 lesions) with IVL. The mean age of patients was 70.9 years (53-94 years) and 68% were male. Acute coronary syndromes were the indication for intervention in 16 patients (73%) and stable angina in 6 (27%). Of all patients, hypertension was present in 96%, dyslipidemia in 73%, diabetes in 41%, and chronic kidney disease in 23%. All lesions treated with IVL were de novo native artery lesions. However, 6 patients had prior CABG. Femoral access was used in 5 cases while 17 cases were done via radial access. IVL was used in the LMS (26%), LAD (39%), LCx (19%) and RCA (16%). During the first 9 months, all procedures were planned with a multidisciplinary team discussing the suitability of IVL after the initial diagnostic angiogram (9 procedures). Overall, 13 procedures (59%) were planned and 9 (41%) received IVL treatment ad hoc. All lesions were pre-dilated with semi-compliant or non-compliant balloons and 1 lesion (5%) needed high pressure OPN pre-dilatation to facilitate crossing with the IVL balloon. After IVL delivery, non-compliant balloons were used in 7 patients (32%), Additional rotational atherectomy was not required. The average number of shock wave pulses delivered was 74 (range: 40-80 pulses). Less than 20% residual stenosis (angiographic success) was achieved in all cases. Stents were deployed in all IVL treated patients. Fifteen patients (68.2%) were discharged home within 24 hours. Acute complications occurred in 4 patients. Coronary perforation complicated the delivery of a stent and was treated with a covered stent. One IVL balloon ruptured after delivering 40 pulses with no adverse consequences. Another patient developed a retroperitoneal hematoma. One patient re-presented seven days after IVL treatment with in-stent thrombus, required urgent CABG, but died 2 days postoperatively. CONCLUSION Coronary calcium modification using IVL is effective in facilitating stent expansion. Technical success rates are high. Patients needing IVL treatment are high risk patients who develop known procedure related complications.