Temporary Mechanical Circulatory Support and Shock Teams in High-Risk Cardiac Surgery: The Strategic Evolution of Protected Cardiac Surgery

Background Protected cardiac surgery is a proactive strategy that applies temporary mechanical circulatory support to prevent perioperative low cardiac output syndrome in high-risk cardiac surgery. Rather than escalating vasoactive agents after hemodynamic decline, the approach emphasizes early identification of physiologic vulnerability and timely initiation of support. Methods We conducted a structured literature review of peer-reviewed studies published from 2000 to 2024 on temporary mechanical circulatory support in adult cardiac surgery. There were 52 studies selected based on relevance to early or prophylactic support, timing of initiation, risk stratification, and systems of care. Clinical insights from multidisciplinary experts also informed the review framework. Results Inotropic escalation after hemodynamic deterioration is consistently associated with poor outcomes. High pharmacologic requirements and severe metabolic derangements predict very high mortality, whereas conventional risk scores often fail to identify vulnerable patients. In contrast, early initiation of mechanical support has been associated with lower in-hospital mortality, reduced dependence on vasoactive agents, and improved recovery. Physiologic markers, such as filling pressures and lactate levels, may provide earlier signals of circulatory decline. Effective implementation also requires institutional coordination, team-based planning, and regional referral systems. Conclusions Protected cardiac surgery reframes success in high-risk cardiac surgery by focusing on recovery rather than survival alone. It integrates physiology-guided support with structured planning and system-level readiness to improve outcomes in vulnerable surgical populations.