Prevention and management of critical care complications in cardiogenic shock: a narrative review

Mechanical circulatory support in cardiogenic shock

Cardiogenic shock is a complex and diverse pathological condition characterized by reduced myocardial contractility. The goal of treatment of cardiogenic shock is to improve abnormal hemodynamics and maintain adequate tissue perfusion in organs. If hypotension and insufficient tissue perfusion persist despite initial therapy, temporary mechanical circulatory support (t-MCS) should be initiated. This decade sees the beginning of a new era of cardiogenic shock management using t-MCS through the accumulated experience with use of intra-aortic balloon pump (IABP) and venoarterial extracorporeal membrane oxygenation (VA-ECMO), as well as new revolutionary devices or systems such as transvalvular axial flow pump (Impella) and a combination of VA-ECMO and Impella (ECPELLA) based on the knowledge of circulatory physiology. In this transitional period, we outline the approach to the management of cardiogenic shock by t-MCS. The management strategy involves carefully selecting one or a combination of the t-MCS devices, taking into account the characteristics of each device and the specific pathological condition. This selection is guided by monitoring of hemodynamics, classification of shock stage, risk stratification, and coordinated management by the multidisciplinary shock team.

Cardiac intensive care unit: where we are in 2023

Cardiac intensive care has been a constantly evolving area of research and innovation since the beginning of the 21st century. The story began in 1961 with Desmond Julian's pioneering creation of a coronary intensive care unit to improve the prognosis of patients with myocardial infarction, considered the major cause of death in the world. These units have continued to progress over time, with the introduction of new therapeutic means such as fibrinolysis, invasive hemodynamic monitoring using the Swan-Ganz catheter, and mechanical circulatory assistance, with significant advances in percutaneous interventional coronary and structural procedures. Since acute cardiovascular disease is not limited to the management of acute coronary syndromes and includes other emergencies such as severe arrhythmias, acute heart failure, cardiogenic shock, high-risk pulmonary embolism, severe conduction disorders, and post-implantation monitoring of percutaneous valves, as well as other non-cardiac emergencies, such as septic shock, severe respiratory failure, severe renal failure and the management of cardiac arrest after resuscitation, the conversion of coronary intensive care units into cardiac intensive care units represented an important priority. Today, the cardiac intensive care units (CICU) concept is widely adopted by most healthcare systems, whatever the country's level of development. The main aim of these units remains to improve the overall morbidity and mortality of acute cardiovascular diseases, but also to manage other non-cardiac disorders, such as sepsis and respiratory failure. This diversity of tasks and responsibilities has enabled us to classify these CICUs according to several levels, depending on a variety of parameters, principally the level of care delivered, the staff assigned, the equipment and technologies available, the type of research projects carried out, and the type of connections and networking developed. The European Society of Cardiology (ESC) and the American College of Cardiology (ACC) have detailed this organization in guidelines published initially in 2005 and updated in 2018, with the aim of harmonizing the structure, organization, and care offered by the various CICUs. In this state-of-the-art report, we review the history of the CICUs from the creation of the very first unit in 1968 to the discussion of their current perspectives, with the main objective of knowing what the CICUs will have become by 2023.

Myocardial stretch-induced compliance is abrogated under ischemic conditions and restored by cGMP/PKG-related pathways

Introduction: Management of acute myocardial infarction (MI) mandates careful optimization of volemia, which can be challenging due to the inherent risk of congestion. Increased myocardial compliance in response to stretching, known as stretch-induced compliance (SIC), has been recently characterized and partly ascribed to cGMP/cGMP-dependent protein kinase (PKG)-related pathways. We hypothesized that SIC would be impaired in MI but restored by activation of PKG, thereby enabling a better response to volume loading in MI. Methods: We conducted experiments in ex vivo rabbit right ventricular papillary muscles under ischemic and non-ischemic conditions as well as pressure-volume hemodynamic evaluations in experimental in vivo MI induced by left anterior descending artery ligation in rats. Results: Acutely stretching muscles ex vivo yielded increased compliance over the next 15 min, but not under ischemic conditions. PKG agonists, but not PKC agonists, were able to partially restore SIC in ischemic muscles. A similar effect was observed with phosphodiesterase-5 inhibitor (PDE5i) sildenafil, which was amplified by joint B-type natriuretic peptide or nitric oxide donor administration. In vivo translation revealed that volume loading after MI only increased cardiac output in rats infused with PDE5i. Contrarily to vehicle, sildenafil-treated rats showed a clear increase in myocardial compliance upon volume loading. Discussion: Our results suggest that ischemia impairs the adaptive myocardial response to acute stretching and that this may be partly prevented by pharmacological manipulation of the cGMP/PKG pathway, namely, with PDE5i. Further studies are warranted to further elucidate the potential of this intervention in the clinical setting of acute myocardial ischemia.