Prospective Assessment of Outcomes in Left Main Coronary Artery Calcium Modification and Angioplasty Using Different Modalities in an Indian Population (PROLEMCA) Study.

Background: Calcification of the left main coronary artery (LMCA) is a critical factor influencing outcomes after percutaneous coronary intervention (PCI) in both LMCA and other coronary arteries. Inadequate lesion preparation can lead to complications like stent thrombosis or restenosis, which result from poor stent expansion and apposition due to reduced vessel compliance.

Aims: This study aims to assess and monitor the short- and long-term outcomes of recent calcium modification techniques, specifically intravascular lithotripsy (IVL), Wolverine cutting balloon (WCB) and rotational atherectomy (RA).

Subjects and methods: The study included 120 consecutive patients who underwent LMCA angioplasty for angiographically significant LMCA disease between January 2017 and December 2019. Patients were pretreated using calcium modification strategies as adjuncts for lesion preparation, including WCB (n = 70), RA (n = 30), and IVL (n = 20). The presence of significant LMCA calcification was confirmed through coronary imaging techniques such as optical coherence tomography (OCT) or intravascular ultrasound (IVUS). Pre-angioplasty imaging was conducted to assess lesion severity, grade the extent of LMCA calcification, and determine the appropriate calcium modification modality for each patient. Post-stenting imaging was performed to evaluate stent expansion, edge dissection, and wall apposition.

Results: A total of 120 patients participated, with a mean age of 6634 years, and shared similar clinical profiles. In-hospital, 5.7% (4 patients) in the WCB group experienced stent thrombosis or required repeat PCI, whereas no such events were reported in the RA or IVL groups. At the 3-year follow-up, the rate of repeat PCI varied significantly across the three groups: WCB (24.3%), RA (6.6%) and IVL (20%). Similarly, the incidence of in-stent restenosis differed: WCB (20%), RA (6.7%) and IVL (25%) respectively. The rate of major adverse cardiovascular events (MACEs) - including myocardial infarction, stroke, heart failure and coronary artery bypass grafting (CABG) - also varied significantly, with the highest proportion observed in the IVL group (55%) compared to WCB and RA (42.9% and 30%, respectively). In-hospital mortality was zero for all groups, but by the end of the study, total mortality was highest in the IVL group (10.0%), compared to WCB (5.7%) and RA (6.7%). The success rate was marginally higher for both WCB and RA at 3 years compared to IVL but not statistically significant.

Conclusion: The IVL group experienced higher rates of MACE and mortality, while the WCB group had the highest rates of stent thrombosis, in-stent restenosis and target vessel revascularisation. Though outcomes for various study endpoints were marginally different for various calcium modification tools, the overall performance regarding the incidence of MACE and mortality, procedural success and secondary outcomes were comparable for all the tools (WCB, RA and IVL) in both the short-term and long-term follow-up.