Mechanical circulatory support in refractory cardiogenic shock due to influenza virus-related myocarditis

Guanylate-binding protein 1 inhibits inflammatory factors produced by H5N1 virus through Its GTPase activity

The combination of inflammatory factors resulting from an influenza A virus infection is one of the main causes of death in host animals. Studies have shown that guinea pig guanosine monophosphate binding protein 1 (guanylate-binding protein 1, gGBP1) can downregulate cytokine production induced by the influenza virus. Therefore, exploring the innate immune defense mechanism of GBP1 in the process of H5N1 influenza virus infection has important implications for understanding the pathogenic mechanism, disease prevention, and the control of influenza A virus infections. We found that, in addition to inhibiting the early replication of influenza virus, gGBP1 also inhibited the production of CCL2 and CXCL10 cytokines induced by the influenza virus as well as the proliferation of mononuclear macrophages induced by these cytokines. These findings further confirmed that gGBP1 inhibited the production of cytokines through its GTPase activity and cell proliferation through its C-terminal α-helix structure. This study revealed the effect of gGBP1 on the production of cellular inflammatory factors during influenza virus infection and determined the key amino acid residues that assist in the inhibitory processes mediated by gGBP1.

Immunopathogenesis and immunomodulatory therapy for myocarditis

Myocarditis is an inflammatory cardiac disease characterized by the destruction of myocardial cells, infiltration of interstitial inflammatory cells, and fibrosis, and is becoming a major public health concern. The aetiology of myocarditis continues to broaden as new pathogens and drugs emerge. The relationship between immune checkpoint inhibitors, severe acute respiratory syndrome coronavirus 2, vaccines against coronavirus disease-2019, and myocarditis has attracted increased attention. Immunopathological processes play an important role in the different phases of myocarditis, affecting disease occurrence, development, and prognosis. Excessive immune activation can induce severe myocardial injury and lead to fulminant myocarditis, whereas chronic inflammation can lead to cardiac remodelling and inflammatory dilated cardiomyopathy. The use of immunosuppressive treatments, particularly cytotoxic agents, for myocarditis, remains controversial. While reasonable and effective immunomodulatory therapy is the general trend. This review focuses on the current understanding of the aetiology and immunopathogenesis of myocarditis and offers new perspectives on immunomodulatory therapies.

Percutaneous Transvalvular Microaxial Flow Pump Support in Cardiology

The Impella device (Impella, Abiomed, Danvers, MA) is a percutaneous transvalvular microaxial flow pump that is currently used for (1) cardiogenic shock, (2) left ventricular unloading (combination of venoarterial extracorporeal membrane oxygenation and Impella concept), (3) high-risk percutaneous coronary interventions, (4) ablation of ventricular tachycardia, and (5) treatment of right ventricular failure. Impella-assisted forward blood flow increased mean arterial pressure and cardiac output, peripheral tissue perfusion, and coronary blood flow in observational studies and some randomized trials. However, because of the need for large-bore femoral access (14 F for the commonly used Impella CP device) and anticoagulation, the incidences of bleeding and ischemic complications are as much as 44% and 18%, respectively. Hemolysis is reported in as many as 32% of patients and stroke in as many as 13%. Despite the rapidly growing use of the Impella device, there are still insufficient data on its effect on outcome and complications on the basis of large, adequately powered randomized controlled trials. The only 2 small and also underpowered randomized controlled trials in cardiogenic shock comparing Impella versus intra-aortic balloon pump did not show improved mortality. Several larger randomized controlled trials are currently recruiting patients or are in preparation in cardiogenic shock (DanGer Shock [Danish-German Cardiogenic Shock Trial; NCT01633502]), left ventricular unloading (DTU-STEMI [Door-To-Unload in ST-Segment-Elevation Myocardial Infarction; NCT03947619], UNLOAD ECMO [Left Ventricular Unloading to Improve Outcome in Cardiogenic Shock Patients on VA-ECMO], and REVERSE [A Prospective Randomised Trial of Early LV Venting Using Impella CP for Recovery in Patients With Cardiogenic Shock Managed With VA ECMO; NCT03431467]) and high-risk percutaneous coronary intervention (PROTECT IV [Impella-Supported PCI in High-Risk Patients With Complex Coronary Artery Disease and Reduced Left Ventricular Function; NCT04763200]).

High rate of critical coronary stenosis in comatose patients with Non-ST-elevation out-of-hospital cardiac arrest (NSTE-OHCA) undergoing therapeutic hypothermia-Experience from the HAnnover COoling REgistry (HACORE)

Background

Myocardial infarction is the most frequent cause for out-of-hospital cardiac arrest (OHCA) in adults. Patients with ST-segment elevations (STE) following return of spontaneous circulation (ROSC) are regularly admitted to the catheterisation laboratory for urgent coronary angiography. Whether patients without obvious STE (NSTE) should receive coronary angiography as part of a standardised diagnostic work-up following OHCA is still debated.

Methods

We analysed a cohort of 517 subsequent OHCA patients admitted at our institution who received a standardised diagnostic work-up including coronary angiography and therapeutic hypothermia. Patients were 63±14 years old, 76% were male. Overall, 180 (35%) had ST-elevation in the post-ROSC ECG, 317 (61%) had shockable rhythm (ventricular fibrillation or tachycardia) at first ECG. ROSC was achieved after 26±21 minutes.

Results

Critical coronary stenosis requiring PCI was present in 83% of shockable and 87% of non-shockable STE-OHCA and in 48% of shockable and 22% of non-shockable NSTE-OHCA patients. In-hospital survival was 61% in shockable and 55% in non-shockable STE-OHCA and 60% in shockable and 28% in non-shockable NSTE-OHCA.

Conclusion

Standardised admission diagnostics in OHCA patients undergoing therapeutic hypothermia with a strict admission protocol incorporating ECG and coronary catheterisation shows a high rate of relevant coronary stenosis in STE-OHCA irrespective of the initial rhythm and in NSTE-OHCA with initial shockable rhythm. Based on the unfavourable outcome and low PCI rate observed in NSTE-OHCA patients with a primary non-shockable ECG rhythm it might be reasonable to restrict routine early coronary angiography to patients with primary shockable rhythms and/or ST-segment elevations after ROSC.

Use of extracorporeal membrane oxygenation for eCPR in the emergency room in patients with refractory out-of-hospital cardiac arrest

Background

Out-of-hospital cardiac arrest (OHCA) refractory to conventional high-quality cardiopulmonary resuscitation (CPR) may be rescued by extracorporeal CPR (eCPR) using veno-arterial extracorporeal membrane oxygenation (V-A ECMO). Even when trying to identify eCPR candidates based on criteria assumed to be associated with a favourable neurological outcome, reported survival rates are frequently below 10%.

Methods

All patients undergoing implantation of V-A ECMO for eCPR between January 2018 and December 2019 (N = 40) were analysed (age 53±13 years; 75% male). Patients with refractory OHCA and potentially favourable circumstances (initial shockable rhythm, witnessed arrest, bystander CPR, absence of limiting comorbidities, age <75 years) were transported under mechanical chest compression. Candidates for eCPR should have a pH ≥6.9, arterial lactate ≤15 mmol/L and time-to-ECMO should be ≤60 minutes.

Results

Overall 30-day survival was 12.5%, with 3 of 5 survivors having a favourable neurological outcome (cerebral performance category (CPC) 1 or 2), representing 7.5% of the total eCPR population. No patient selected for eCPR met all pre-defined criteria (median of unfavourable criteria: 3). Importantly, time-to-ECMO most often (39/40) exceeded 60 minutes (mean 102 ±32 min.), and lactate was >15mmol/L in 30 out of 40 patients. Moreover, 22 out of 40 patients had a non-shockable rhythm on the first ECG.

Conclusions

Despite our intention to select patients with potentially advantageous circumstances to achieve acceptable eCPR outcomes, the imminent deadly consequence of withholding eCPR obviously prompted individual physicians to perform the procedure also in presumably more unfavourable settings, resulting in similar mortality rates of eCPR as reported before.

Extracorporeal Cardiopulmonary Resuscitation for Management of Out-of-Hospital Cardiac Arrest in a Patient with Fulminant Myocarditis

A 68-year-old male with a witnessed out-of-hospital cardiac arrest while jogging who was managed with extracorporeal cardiopulmonary resuscitation (ECPR) is presented. The patient was found to be in refractory ventricular fibrillation by emergency medical service personnel and underwent advanced cardiac life support (ACLS) protocol with placement of an automated chest compression device. He was emergently transported to the cardiac catheterization laboratory. Due to refractory ventricular fibrillation, he was placed on venoarterial extracorporeal membranous oxygenation (VA-ECMO). Coronary angiography at that time showed nonobstructive coronary artery disease. Management with VA-ECMO and other supportive measures were continued for 5 days, after which a cardiac magnetic resonance imaging was performed with findings consistent with acute myocarditis. His condition substantially improved, and he was discharged from the hospital with good neurologic and functional status. Fulminant myocarditis is often fatal, but aggressive supportive measures with novel ECPR protocols may result in recovery, as it happened in this case.