Long term outcomes in patients undergoing Impella protected high-risk percutaneous coronary intervention: insights from the international IMMERGE registry

Background Mechanical circulatory support with percutaneous ventricular assist devices (pVADs) has progressively expanded its role in the management of complex high-risk indicated percutaneous coronary interventions (CHIP). Among pVADs, Impella provides active left ventricular unloading and hemodynamic stabilization, potentially allowing safer and more complete revascularization in patients with advanced coronary artery disease and impaired cardiac function. However, robust long-term outcome data in this setting remain limited. Objectives To evaluate long-term clinical outcomes, procedural safety, and predictors of mortality in patients undergoing Impella-protected CHIP, using data from the international IMMERGE registry Methods IMMERGE was an international, multicenter, observational registry including patients treated with Impella CP, 5.0, or 5.5 for cardiogenic shock or high-risk PCI among 19 centers across the world between 2013 and 2025. The present analysis focused on 570 consecutive patients who underwent Impella-supported CHIP, with follow-up censored at 2 years. The primary endpoint was all-cause mortality, whereas secondary endpoints included in-hospital complications and long-term adverse events. Multivariable Cox regression analysis was performed to identify independent predictors of mortality. Results The study population was predominantly male (82.3%), with a mean age of 71.7 ± 10.5 years and a high burden of cardiovascular comorbidities. Impella CP was used in 99.1% of cases, with device implantation performed before PCI in 81.0%. The most common PCI target was left anterior descending artery (LAD), accounting for 81.7% of cases; a bifurcation PCI was carried out in 367 patients, of whom 179 (48.8%) were treated with provisional stenting. Intracoronary imaging was performed in 52.5% of patients, mostly IVUS (48.4%). At 2-years censored follow-up, all-cause mortality was 19.8%, with an in-hospital mortality of 3.6% and 30-day mortality of 8.7%. Acute kidney injury (15.1%), vascular complications (14.5%), and major bleeding (13.8%) were the most frequent in-hospital adverse events. Independent predictors of long-term mortality included STEMI presentation, advanced age, diabetes mellitus and major bleeding (BARC 3–5). Conclusions In a large real-world, international cohort, Impella-protected CHIP was associated with acceptable early mortality and meaningful long-term survival. Although periprocedural complication rates remain non-negligible, these were lower than reported in the historical cohorts due to the increased operators’ expertise and ICU management.