Moving Beyond SHOCK: New Paradigms in the Management of Acute Myocardial Infarction Complicated by Cardiogenic Shock

MicroRNA-126 enhances the biological function of endothelial progenitor cells under oxidative stress via PI3K/Akt/GSK3β and ERK1/2 signaling pathways

Endothelial progenitor cell (EPC) transplantation is a safe and effective method to treat acute myocardial infarction (AMI). However, oxidative stress leads to the death of a large number of EPCs in the early stage of transplantation, severely weakening the therapeutic effect. Previous studies demonstrated that microRNAs regulate the biological function of EPCs. The aim of the current study was to investigate the effect of microRNA on the biological function of EPCs under oxidative stress. Quantitative reverse transcription PCR was performed to detect the expression of miR-126, miR-508-5p, miR-150, and miR-16 in EPCs from rats, among which miR-126 showed a relatively higher expression. Treatment with H₂O₂ decreased miR-126 expression in EPCs in a dose-dependent manner. EPCs were further transfected with miR-126 mimics or inhibitors, followed by H₂O₂ treatment. Overexpression of miR-126 enhanced the proliferation, migration, and tube formation of H₂O₂-treated EPCs. MiR-126 overexpression also inhibited reactive oxygen species and malondialdehyde levels and enhanced superoxide dismutase levels, as well as increased angiopoietin (Ang)1 expression and decreased Ang2 expression in H₂O₂-treated EPCs. Moreover, miR-126 participated in the regulation of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/glycogen synthase kinase 3β (GSK3β) and extracellular signal-regulated kinase 1/2 (ERK1/2) signaling in EPCs, where both pathways were activated after miR-126 overexpression in H₂O₂-treated EPCs. Overall, we showed that miR-126 promoted the biological function of EPCs under H₂O₂-induced oxidative stress by activating the PI3K/Akt/GSK3β and ERK1/2 signaling pathway, which may serve as a new therapeutic approach to treat AMI.

Percutaneous Left Ventricular Assist Device Leads to Heart Rhythm Stabilisation in Cardiogenic Shock: Results from the Dresden Impella Registry

BACKGROUND

Severe heart rhythm disturbances (SHRDs) occur regularly in cardiogenic shock (CS). Percutaneous left ventricular assist devices (pLVADs) can actively unload the left ventricle (LV), decreasing left ventricular end-diastolic pressure and wall tension, which are suspected parameters for the induction and maintenance of arrhythmias. The aim of this study was to describe effects of LV unloading on SHRD.

METHOD

In the Dresden Impella Registry, 97 patients received an Impella CP in refractory CS. Of them, 19 had SHRDs, which were not stopped by common therapeutic strategies such as electrical defibrillation or antiarrhythmic drugs. They were only stopped after implantation of a micro-axial heart pump. This phenomenon was referred to as heart rhythm stabilisation (HRS). Clinical outcome and laboratory parameters were assessed and risk factors for the occurrence of HRS were identified.

RESULTS

All 19 patients with refractory SHRD terminated immediately into a stable heart rhythm after insertion of the micro-axial heart pump. In 37% no additional defibrillation was needed. Of the patients with HRS, CS was mostly caused by myocardial infarction (68%). Resuscitation before pLVAD was performed in 89% for more than 30 minutes. Patients with HRS were resuscitated more frequently and for a longer duration than patients without HRS. After HRS, the serum lactate and norepinephrine dosage decreased in the first 12 hours, whereas left ventricular ejection fraction increased by 95%.

CONCLUSIONS

Left ventricular unloading in patients with CS seems to be an option for treating patients with sustained life-threatening tachycardia, who are refractory to common treatment.

Development and Testing of a Novel Anaesthesia Induction/Ventilation Protocol for Patients With Cardiogenic Shock Complicating Acute Myocardial Infarction

BACKGROUND

Cardiogenic shock is a life-threatening condition and patients might require rapid sequence induction (RSI) and mechanical ventilation. In this study, we evaluated a new RSI/mechanical ventilation protocol in patients with acute myocardial infarction complicated by cardiogenic shock.

METHODS

We included consecutive adult patients who were transferred to the emergency department. The RSI protocol included 5 phases: preoxygenation, pretreatment, induction/paralysis, intubation, and mechanical ventilation (PPIIM). A posteriori, we selected historical patients managed with standard RSI as a control group. The primary outcome was hemodynamic derangement or hypoxemia from enrollment until intensive care unit (ICU) admission.

RESULTS

We studied 31 consecutive patients who were intubated using the PPIIM protocol and 22 historical controls. We found significant differences in systolic (85.32 ± 4.23 vs 71.72 ± 7.98 mm Hg; P < 0.0001), diastolic (58.84 ± 5.84 vs 39.05 ± 5.63 mm Hg; P < 0.0001), and mean arterial pressure (67.71 ± 4.90 vs 49.90 ± 5.66 mm Hg; P < 0.0001), as well as in partial pressure of oxygen (85.80 ± 19.82 vs 164.73 ± 43.07 mm Hg; P < 0.0001) between the PPIIM and control group at 5 minutes of automated ventilation. Also, statistically significant differences were observed in diastolic (59.74 ± 4.93 vs 47.86 ± 11.47 mm Hg; P < 0.0001) and mean arterial pressure (68.65 ± 4.10 vs 60.23 ± 11.67 mm Hg; P < 0.0001), as well as in partial pressure of oxygen (119.84 ± 50.57 vs 179.50 ± 42.17 mm Hg; P < 0.0001), and partial pressure of carbon dioxide (39.81 ± 10.60 vs 31.00 ± 9.30 mm Hg; P = 0.003) between the 2 groups at ICU admission. Compared with the control group, with PPIIM more patients survived to ICU admission (100% vs 77%) and hospital discharge (71% vs 31.8%), as well as at 90 days (51.6% vs 18.2%), and at 180 days (38.7% vs 13.6%).

CONCLUSIONS

The PPIIM protocol allows safe intubation of acute myocardial infarction patients with cardiogenic shock and improves hemodynamic and oxygenation parameters.

'Combat' Approach to Cardiogenic Shock

The incidence of cardiogenic shock is rising, patient complexity is increasing and patient survival has plateaued. Mirroring organisational innovations of elite military units, our multidisciplinary medical specialists at the INOVA Heart and Vascular Institute aim to combine the adaptability, agility and cohesion of small teams across our large healthcare system. We advocate for widespread adoption of our 'combat' methodology focused on: increased disease awareness, early multidisciplinary shock team activation, group decision-making, rapid initiation of mechanical circulatory support (as appropriate), haemodynamic-guided management, strict protocol adherence, complete data capture and regular after action reviews, with a goal of ending preventable death from cardiogenic shock.