The Impact of Atherectomy in Severely Calcified Lesions in Impella-Supported High-Risk Percutaneous Coronary Intervention

Severe coronary artery calcification (CAC) complicates high-risk percutaneous coronary intervention (HRPCI), particularly in patients with impaired left ventricular function. Atherectomy may facilitate lesion preparation, but its use in high-risk settings is limited. We therefore aimed to assess the impact of CAC severity and atherectomy on outcomes in Impella-supported HRPCI. In the PROTECT III study (NCT04136392), 1015 of 1237 patients had data on CAC severity and atherectomy. Patients were grouped as severe CAC without atherectomy (n=298), severe CAC with atherectomy (n=326), and no severe CAC (n=400). The primary endpoint was major adverse cardiovascular and cerebrovascular events (MACCE: all-cause death, myocardial infarction, stroke/TIA, or repeat revascularization) at 30- and 90-days. Secondary endpoints included 1-year mortality, PCI-related complications, and hemodynamic instability. Patients with severe CAC had higher baseline SYNTAX scores and more left main disease. Atherectomy was associated with slightly longer procedural times, but not increased periprocedural complications or hemodynamic instability. At 90 days, MACCE was highest in the untreated severe CAC group (16.1% vs. 12.6% vs. 9.2%; overall log-rank p=0.048). One-year mortality was also highest in this group (23.7%; p=0.02). However, CAC severity and atherectomy use were not independent predictors of outcomes. Sensitivity analysis excluding patients with atherectomy but no severe CAC showed higher mortality risk in untreated severe CAC cases (adjHR: 0.59; overall p=0.026). In conclusion, Severe CAC is common in patients undergoing Impella-supported HRPCI and is associated with worse outcomes. Atherectomy was safe but its benefit remains uncertain. These findings highlight the prognostic relevance of CAC and the potential role of calcium modification in HRPCI.