Patients in this arm receive temporary mechanical circulatory support with the Impella CP transvalvular axial-flow pump operating in Auto-mode (SmartAssist) throughout the protected high-risk percutaneous coronary intervention. In Auto-mode, pump speed (P-level) is automatically adjusted in real time based on hemodynamic feedback, with maximum flow up to approximately 4.3 L/min.

Patients in this arm receive temporary mechanical circulatory support with the Impella CP transvalvular axial-flow pump operating in the fixed P-2 setting (approximately 1.3-2.1 L/min flow) at the start of the procedure. The unblinded study investigator continuously monitors hemodynamics during the procedure and is empowered to escalate Impella support to a higher P-level (or Auto-mode) without operator confirmation if any predefined hemodynamic instability criterion is met (MAP drop ≥ 25 mmHg, MAP < 60 mmHg for > 1 minute, flat line, catecholamine need, periprocedural resuscitation, or ventilation).

The Impella CP is a transvalvular axial-flow micro-pump for temporary mechanical circulatory support, inserted via a 14F sheath into the femoral artery and positioned across the aortic valve. The pump draws blood from the left ventricle and delivers it to the ascending aorta, providing forward flow up to approximately 4.3 L/min while reducing left ventricular work and end-diastolic pressure. In this study, the device is used in all participants undergoing protected high-risk PCI, with the operating modality (Auto-mode in the experimental arm vs. fixed P-2 mode in the active comparator arm) determined by 1:1 randomization. The unblinded study investigator may escalate Impella support if predefined hemodynamic instability criteria are met.

The primary endpoint is strategy success, defined as completing the procedure with successful uncomplicated PCI of all intended segments with a TIMI flow of 3 and residual stenosis of less than 30% without hemodynamic instability. Hemodynamic instability in our study is defined as 25 mmHg (as defined in past randomized studies) decrease on baseline mean arterial pressure (MAP) for longer than 1 minute or MAP of under 60 mmHg for longer than 1 minute, flat line, administration of any dose of catecholamines, change on Impella CP modality, periprocedural resuscitation and/or ventilation. Complications are defined as periprocedural resuscitation, emergency surgery, periprocedural ventilation, death, periprocedural myocardial infarction type 4a based on the 4th universal definition of myocardial infarction (35), periprocedural acute renal injury based on the 2012 KDIGO definition of acute kidney injury (36), bleeding BARC type 3 or 5.

Proportion of participants who die from any cause within 30 days after the index protected high-risk PCI procedure.

Proportion of participants undergoing any clinically driven repeat revascularization (PCI or CABG) of the target lesion within 30 days after the index procedure.