Stein, Louis H.

Abstract Perioperative low cardiac output syndrome (LCOS) remains a significant complication in adult cardiac surgery, contributing to substantial morbidity, prolonged intensive care, and increased mortality. Its incidence is expected to rise further due to the evolving complexity of referred surgical patients, often characterised by advanced age, multiple comorbidities, challenging anatomy, and impaired haemodynamics. Despite advances in pharmacological and perioperative care, outcomes for high-risk patients have not shown significant improvement, prompting interest in temporary mechanical circulatory support (tMCS) as a proactive strategy. This Expert Consensus Document from the European Association for Cardio-Thoracic Surgery (EACTS) presents the first dedicated guidance on the pre-emptive use of tMCS in high-risk adult cardiac surgical patients. Developed by a multidisciplinary task force, it emphasises structured risk stratification, early initiation, and individualised device management informed by interdisciplinary Heart Team discussions. The document proposes clinical pathways for patient selection, defines criteria for tMCS initiation, and provides practical algorithms for various scenarios, including advanced heart failure, cardiogenic shock, and post-cardiotomy LCOS. It reviews the current evidence on available tMCS devices, such as intra-aortic balloon pumps, microaxial flow pumps, veno-arterial extracorporeal life support and hybrid strategies, and addresses perioperative care, intensive care unit protocols, ethical considerations, as well as informed consent and support withdrawal. Despite promising results, substantial knowledge gaps remain, including long-term outcome data, device selection criteria, and cost-effectiveness analyses. This consensus aims to support clinical decision-making, standardise practice, and stimulate research to improve outcomes in a growing population of high-risk surgical patients.

AbstractThe heterotrimeric guanine nucleotide-binding protein Gαi2 is involved in regulation of immune responses against microbial and nonmicrobial stimuli. Gαi2−/− mice have a selectively impaired IgM response consistent with a disorder in B cell development yet have augmented T cell effector function associated with increased production of IFN-γ and IL-4. The goal of the present study was to determine if a deficiency in the Gαi2 protein in mice would affect the protective immune response against Strongyloides stercoralis, which is IL-4-, IL-5-, and IgM-dependent. Gαi2−/− and wild-type mice were immunized and challenged with S. stercoralis larvae and analyzed for protective immune responses against infection. Gαi2−/− mice failed to kill the larvae in the challenge infection as compared with wild-type mice despite developing an antigen-specific Th2 response characterized by increased IL-4, IL-5, IgM, and IgG. Transfer of serum collected from immunized Gαi2−/− mice to naïve wild-type mice conferred passive protective immunity against S. stercoralis infection thus confirming the development of a protective antibody response in Gαi2−/− mice. Differential cell analyses and myeloperoxidase assays for quantification of neutrophils showed a significantly reduced recruitment of neutrophils into the microenvironment of the parasites in immunized Gαi2−/− mice. However, cell transfer studies demonstrated that neutrophils from Gαi2−/− mice are competent in killing larvae. These data demonstrate that Gαi2 signaling events are not required for the development of the protective immune responses against S. stercoralis; however, Gαi2 is essential for the recruitment of neutrophils required for host-dependent killing of larvae.