PCCS & LCOS

Understanding Risk Factors Associated with LCOS/PCCS Across Different Population Groups ^2,5,4

Patients with post-cardiotomy cardiogenic shock (LCOS/PCCS) have persistent low cardiac output syndrome (LCOS) manifesting as inability to wean from cardiopulmonary bypass (CPB) or severe cardiac dysfunction in the immediate postoperative period despite optimal medical therapy. LCOS/PCCS most commonly arises after coronary artery bypass graft (CABG) or valve replacement surgery and may involve left, right, or biventricular failure. The incidence of LCOS/PCCS is 2% to 20%. ⁷

Like patients with classic heart failure, patients with LCOS/PCCS may present with left, right, or biventricular impairment accompanied by pulmonary congestion. Unlike cardiogenic shock associated with acute myocardial infarction (AMI), in which patients typically present with elevated systemic vascular resistance (SVR), LCOS/PCCS is often associated with decreased SVR due to increased vasodilation. Mahajna et al. write, “up to 50% of patients with PCCS experience vasodilatory shock, characterized by the dual challenges of myocardial stunning and systemic vasodilation. This unique hemodynamic profile underscores the critical role of tMCS in managing PCCS.” ⁸
 

Patient Management in LCOS/PCCS⁸

In their paper “Current Insights on Temporary Mechanical Circulatory Support in Adults with Post-Cardiotomy Cardiogenic Shock” Mahajna et al. describe four key pillars underpinning the diagnosis and monitoring of LCOS/PCCS: echocardiography, pulmonary artery catheter (PAC) data, vasoactive inotropic score (VIS), and serial lactate measurements. When patients fail to wean from CPB, it is essential to assess potential contributing factors to guide management decisions. If, despite addressing these factors and providing optimal medical therapy, repeated weaning attempts fail, an immediate transition to temporary mechanical circulatory support (tMCS) is warranted. The Successful management of LCOS/PCCS hinges on early identification of patients whose cardiac function is unlikely to recover rapidly and timely initiation and selection of tMCS.

A collaborative, multidisciplinary, Heart Team comprising cardiologists, cardiac surgeons, interventionalists, and anesthesiologists, is increasingly recognized as a best practice in managing LCOS/PCCS. “This model not only enhances survival rates but also aims to improve the quality of life for patients by promoting precise, innovative, and cooperative care planning.” ¹¹

Preparing for the potential need for tMCS in high-risk patients is critical. It is also important to discuss weaning of patients from tMCS, noting that only 30-70% of patients with cardiogenic shock undergoing tMCS therapy can be successfully weaned.¹¹ 

The multidisciplinary Heart Team plays a key role in optimizing patient management and reassessing treatment strategies in patients deemed unsuitable for tMCS removal.
 

Timely application of temporary MCS (tMCS) in patients with LCOS/PCCS can improve survival from near-zero to between 25% and 42%.⁷ 

Mahajna et al. write “Effective management of PCCS requires not only restoration of cardiac output but also maintenance of adequate perfusion pressure to ensure end-organ perfusion.”⁸ Supporting patients with tMCS before severe end-organ malperfusion or ischemia develop is important, as these are key predictors of mortality in LCOS/PCCS.

LCOS/PCCS Management

When LCOS/PCCS manifests in patients who fail to wean from CPB, and repeated weaning attempts fail despite attempts to optimize the clinical situation and medical therapy, an immediate transition to tMCS is warranted. 

Early, and sometimes even pre-emptive, initiation of tMCS —“ideally before significant end-organ injury or the onset of anaerobic metabolism (lactate level >4 mmol/L)”¹², say Mahajna et al. —is also warranted in cases of refractory LCOS after CPB.

Prophylactic cardiocirculatory assistance is also discussed to reduce LCOS/PCCS. In their paper Mahajna et al. write, “There is mounting evidence that the concept consistently applied in high-risk patients undergoing percutaneous coronary intervention (PCI), known as the Protected PCI, may be beneficial in cardiac surgery patients as well.”¹⁰ This approach may provide support from the immediate pre-operative to the early postoperative phases in cardiac surgery.

IABP is often considered as an early intervention in LCOS/PCCS because it is easy to use with a favorable safety profile; however, IABP has limited capacity to reverse shock and patients often require escalation to more robust tMCS such as veno-arterial ECMO (VA-ECMO). Combining Impella® with ECMO can help unload the left ventricle. This combination of tMCS “has been shown to significantly reduce early mortality and is emerging as a promising strategy for improving outcomes in these patients.”¹⁰ Also, right ventricular assist devices, such as Protek Duo, Impella® RP, and TandemHeart are discussed for patients with ongoing RV Failure.