Microvascular obstruction (MVO) of coronary arteries increases the mortality rate and major adverse cardiac events in patients with acute myocardial infarction (AMI) and percutaneous coronary intervention (PCI). According to preliminary data platelets, inflammation, Ca2+ overload, neuropeptide Y, and endothelin-1 could be involved in the pathogenesis of MVO. Many questions related to the pathogenesis of MVO remain unanswered. The role of endothelial cell damage in the formation of MVO in patients with AMI and PCI is unknown. It is unclear whether nitric oxide (NO) production reduces or decreases sensitivity of smooth muscle cells of coronary arteries to NO in patients with MVO. It was obtained only indirect evidence on the involvement of inflammation in the development of MVO. The role of ROS in the pathogenesis of MVO is not studied. The role of necroptosis and pyroptosis in the pathogenesis of MVO in patients with AMI and PCI is also not studied.The significance of thromboxane A, vasopressin, angiotensin II, and prostacyclin in the formation of MVO is unknown before. It was not obtained conclusive evidence on the involvement of coronary artery spasm in the development of MVO. Correlation analysis of the neuropeptide Y, endothelin-1 levels and the MVO size in patients with AMI and PCI was not performed. It is not clear whether endogenous adrenaline exacerbates MVO or, conversely, prevents MVO.

Aim . To evaluate the efficacy and safety of intracoronary epinephrine for the treatment of refractory no-reflow phenomenon in patients with ST-segment elevation myocardial infarction (STEMI) during percutaneous coronary intervention (PCI). Material and methods . A single-site prospective controlled study “Intracoronary administration of epinephrine for refractory no-reflow phenomenon in patients with acute myocardial infarction” was conducted (registration on ClinicalTrials.gov: NCT04573751). The study included 40 patients with refractory no-reflow phenomenon, which was identified when it was not resolved with at least one of the following means: nitroglycerin, adenosine, papaverine, platelet receptor inhibitors IIB/IIIA, or thromboaspiration. Patients were divided into 2 groups: patients of group 1 (n=18) were injected with intracoronary epinephrine 100 μg, patients of group 2 (n=22) received standard therapy without epinephrine. The groups did not differ in the main baseline clinical and anamnestic characteristics, with the exception of the predominance of men in the control group: 86.4% vs. 55.6% (p=0.03). Results. In the epinephrine group, TIMI 3 blood flow was more often achieved: 55.6% vs. 0% (p50% within 1 hour after PCI: 72.2% vs. 31.8% (p=0.01). Concentrations of troponin I 12-24 h after PCI were significantly lower in the epinephrine group than in the control group: 15.2 (6;25) ng/ml vs. 25 (10;40) ng/ml (p=0.03). No life-threatening hemodynamic disorders or cardiac arrhythmias were recorded after the administration of epinephrine. No statistically significant differences were found in cardiac ultrasound data and MACE (Major Adverse Cardiovascular Events) during 30 days of follow-up. Conclusions . Intracoronary epinephrine 100 μg in STEMI patients with refractory no-reflow phenomenon during PCI is a safe and effective method for improving the blood flow in the infarct-related coronary artery. The prevalence of refractory no-reflow phenomenon among STEMI patients in our study reached 4.6%.

Despite modern advances in performing percutaneous coronary interventions, refractory no-reflow remains a serious problem that worsens in-hospital and long-term prognosis. Low-dose adrenaline may exhibit potent beta-receptor agonist properties that mediate coronary vasodilation.Aim. To evaluate the efficacy and safety of intracoronary administration of epinephrine and verapamil, as well as their combination, compared with standard treatment in patients with ST-segment elevation myocardial infarction (STEMI) and refractory no-reflow during percutaneous coronary interventions.Material and methods. Patients with STEMI and refractory no-reflow will be randomized into 4 groups: standard therapy, intracoronary adrenaline, intracoronary verapamil, intracoronary epinephrine + verapamil. All patients will be assessed for epicardial blood flow using the Thrombolysis in Myocardial Infarction (TIMI) and Myocardial Blush Grade (MBG) scales, peak troponin levels, ST segment changes, echocardiography, magnetic roesnance imaging, and dynamic single photon emission computed tomography.Results. Based on the pharmacodynamic effects of epinephrine and verapamil, their combination is expected to have a more potent vasodilating effect.Conclusion. If the Intracoronary administration of EPInephrine and VERapamil in the refractory no-reflow phenomenon (EPIVER) study will be successful, a novel, more effective method for managing refractory no-reflow phenomenon will appear. This will ensure better preservation of left ventricular systolic function, as well as improve the prognosis and clinical course of the disease.

Background and Objectives: In-hospital mortality associated with myocardial infarction complicated by cardiogenic shock (MI-CS) remains critically high. A particularly challenging form, mixed shock (MS), combines features of cardiogenic shock (CS) with distributive elements such as vasodilation and reduced vascular resistance. MS is associated with elevated mortality rates and presents unique diagnostic and therapeutic challenges. This study aimed to analyze the clinical, historical, instrumental, and laboratory characteristics of the primary phenotypes of MI-CS, stratified according to the Society for Cardiovascular Angiography and Interventions (SCAI) shock severity scale. Materials and Methods: In this single-center, retrospective observational study, we reviewed the medical records of 1289 patients admitted to the emergency cardiology department from 1 January to 12 December 2020. Among them, 117 patients were identified as having MI-CS and were divided into two groups: MS (n = 48) and isolated CS (n = 69). The data were analyzed using the SCAI shock classification. Logistic regression analysis was employed to identify predictors of mortality and improved survival outcomes. Results: Patients with MS were older (80 years [71.0; 83.0] vs. 73 years [64.0; 81.0], p = 0.035). The overall mortality rate was significantly higher in the MS group (68% vs. 53%, RR = 1.438, 95% CI: 1.041–1.986, p = 0.03). Logistic regression identified mechanical ventilation (OR = 8.33, 95% CI: 2.54–22.80, p = 0.012), elevated lactate levels (OR = 1.20, 95% CI: 1.02–1.41, p = 0.026), and cardiopulmonary resuscitation (CPR) (OR = 7.97, 95% CI: 2.51–24.40, p < 0.0001) as independent predictors of mortality. Conversely, the use of an intra-aortic balloon pump (IABP) (OR = 0.22, 95% CI: 0.06–0.80, p = 0.021) and a higher body mass index (BMI) (OR = 0.91, 95% CI: 0.84–0.99, p = 0.038) were associated with reduced mortality risk. Conclusions: MS in the context of MI-CS represents a distinct clinical phenotype with specific hemodynamic features and significantly worsened outcomes. The identification of mortality predictors, such as mechanical ventilation, elevated lactate levels, and CPR, alongside protective factors like IABP use and a higher BMI, underscores the importance of early and tailored therapeutic interventions. These findings highlight the need for further studies to refine treatment protocols and improve outcomes in this high-risk population.