Influence of Total Ischemic Time on Clinical Outcomes in Patients with ST-Segment Elevation Myocardial Infarction

Protective effects of fructose-1,6-bisphosphate postconditioning on myocardial ischaemia-reperfusion injury in patients undergoing valve replacement: a randomized, double-blind, placebo-controlled clinical trial

OBJECTIVES

Pharmacological postconditioning can protect against myocardial ischaemia-reperfusion injury during cardiac surgery with extracorporeal circulation. The aim of this study was to observe the protective effects of fructose-1,6-bisphosphate (FDP) postconditioning on myocardial ischaemia-reperfusion injury in patients undergoing cardiac valve replacement with extracorporeal circulation.

METHODS

Patients undergoing elective mitral valve replacement and/or aortic valve replacement were divided into normal saline postconditioning group (NS group) and FDP postconditioning group (FDP group). The primary outcome was the plasma concentration of creatine kinase-MB (CK-MB). The secondary outcomes were the plasma concentrations of lactate dehydrogenase, CK, high-sensitivity C-reactive protein, alpha-hydroxybutyrate dehydrogenase and cardiac troponin I, the spontaneous cardiac rhythm recovery profile, the extracorporeal circulation time and duration of surgery, intensive care unit and postoperative hospitalization.

RESULTS

Forty patients were randomly assigned to receive intervention and included in the analysis. The serum concentrations of CK-MB, lactate dehydrogenase, CK, cardiac troponin I, alpha-hydroxybutyrate dehydrogenase and high-sensitivity C-reactive protein at T1∼4 were lower in the FDP group than in the NS group (P < 0.001). Compared with the NS group, the dosage of dopamine administered 1-90 min after cardiac resuscitation, the spontaneous cardiac rhythm recovery time and the incidence of ventricular fibrillation were lower in the FDP group (P < 0.001, P < 0.001 and P = 0.040, respectively). The values of ST- changes were increased more significantly in the NS group than in the FDP group (median [standard deviation] 1.3 [0.3] mm vs 0.7 [0.2] mm; P < 0.001). Compared with the NS group, the time of recovery of ST-segment deviations was shorter in the FDP group (50.3 [12.3] min vs 34.6 [6.9] min; P < 0.001).

CONCLUSIONS

The FDP postconditioning could improve both myocardial ischaemia-reperfusion injury and the spontaneous cardiac rhythm recovery during cardiac valve surgery with extracorporeal circulation.

Factors Associated with Symptom-to-Door Delay in Patients with ST-Segment Myocardial Infarction: A Systematic Review

BACKGROUND

Decreasing symptom-to-door (S2D) delay is of vital importance for reducing morbidity and mortality in patients with ST-segment elevation myocardial infarction (STEMI). The factors associated with S2D delay in STEMI patients have not been well-characterized.

OBJECTIVES

The aim of this study was to identify factors associated with S2D delay in patients with STEMI.

METHODS

The PubMed, CINAHL, and Embase databases were searched for data. References from the selected articles and relevant background papers were also manually searched to identify additional eligible studies. The included articles were reviewed and assessed for risk of bias. The level of evidence for each identified factor was evaluated using a semiquantitative synthesis.

RESULTS

Twelve (12) papers were included in the review. Factors associated with S2D delay were complex and could be divided into sociodemographic, clinical history, and onset characteristics. The level of evidence regarding female sex and diabetes was strong, and the evidence was moderate regarding older age, smoking, history of hypertension, self-transport, or referral.

CONCLUSIONS

Female sex, older age, previous diabetes, previous hypertension, smoking, and self-transport are all strong or moderate risk factors for S2D time delay in patients with ST-segment myocardial infarction. More efforts should be made to educate at-risk populations concerning symptoms of STEMI and the importance of seeking early medical assistance.

Effect of the "door-to-balloon" time on the results of treatment of patients with ST-segment elevation myocardial infarction, depending on the duration of the pre-hospital delay

Aim    To analyze the effect of the door-to-balloon time on treatment outcomes in patients with acute ST-segment elevation myocardial infarction (STEMI) depending on the duration of pre-hospital delay.Material ad methods    The study used data of the hospital registry of percutaneous coronary interventions (PCI) in STEMI from 2006 through 2017. The analysis included 1333 patients. All patients were divided into two groups. The first group included 574 (43.1%) patients with the time from the pain syndrome onset to admission was ≤120 min. The second group consisted of 759 (56.9 %) patients with the time of pre-hospital delay exceeding 120 min. Results of the treatment were analyzed for each group depending on the door-to-balloon time, ≤60 min or &gt;60 min.Results    In the group of patients with the prehospital delay less than 120 min and the door-to-balloon time ≤60 min vs. patients with the door-to-balloon time &gt;60 min, the following was observed: decreased in-hospital mortality (1.3 % vs. 6.8 %, p=0.001), reduced incidence of major adverse cardiac effects (МАСЕ) (3.2 % vs. 8.3 %, p=0.008), and reduced incidence of the no-reflow phenomenon (3.9 % vs. 9.4 %, p=0.007). Also, immediate angiographic success of PCI was more frequently achieved in these patents (94.5 % vs. 87.5 %, p=0.003). In addition, in the group with the prehospital delay ≤120 min and the door-to-balloon time ≤60 min, a higher ejection fraction was noted at discharge from the hospital (48 [43; 51] % vs. 46 [42; 51] %, р=0.038). Comparison of treatment outcomes between the groups with different door-to-balloon time (≤60 min or &gt;60 min) and a prehospital delay &gt;120 min did not show any significant intergroup differences. According to a multivariate analysis, the door-to-balloon time ≤60 min did not predict in-hospital mortality. There was a strong correlation between the time of prehospital delay and the total time of myocardial ischemia (r=0.87; р&lt;0.001) while the correlation between the door-to-balloon time and the total time of myocardial ischemia was moderate (r=0.41; р&lt;0.001). At the same time, there was no correlation between the time of prehospital delay and the door-to-balloon time.Conclusion    In STEMI patients with a prehospital delay less than 120 min from the pain syndrome onset, a decrease in the door-to-balloon time was associated with better outcome of the hospital treatment. When the duration of prehospital delay was more than 120 min, a decrease in door-to-balloon time did not influence the treatment outcome. The time of prehospital delay strongly correlated with the total time of myocardial ischemia.

Shorter door-to-balloon time, better long-term clinical outcomes in ST-segment elevation myocardial infarction patients: J-MINUET substudy

BACKGROUND

The impact of shorter door-to-balloon (DTB time on long-term outcomes in ST-segment elevation myocardial infarction (STEMI treated with primary percutaneous coronary intervention (PPCI has not been fully elucidated.

METHODS

We investigated 3283 consecutive patients with acute myocardial infarction selected from a prospective, nationwide, multicenter registry (J-MINUET database comprising 28 institutions in Japan between July 2012 and March 2014. Among the study population, we analyzed 1639 STEMI patients who had PPCI within 12 h of onset. Patients were stratified into four groups (DTB time < 45 min, 45-60 min, 61-90 min, >90 min. The primary endpoint was a composite of all-cause death, non-fatal MI, non-fatal stroke, cardiac failure, and urgent revascularization for unstable angina up to 3 years. We performed landmark analysis for incidence of the primary endpoint from 31 days to 3 years among the four groups.

RESULTS

The primary endpoint rate from 31 days to 3 years increased significantly and time-dependently with DTB time (10.2 % vs. 15.3 % vs. 16.2 % vs. 19.3 %, respectively; log-rank p = 0.0129. Higher logarithm-transformed DTB time was associated with greater risk of a primary endpoint from 31 days to 3 years, and the increased number of adverse long-term clinical outcomes persisted even after adjusting for other independent variables.

CONCLUSION

Shorter DTB time was associated with better long-term clinical outcomes in STEMI patients treated with PPCI in contemporary clinical practice. Further efforts to shorten DTB time are recommended to improve long-term clinical outcomes in STEMI patients.

TRIAL REGISTRATION

UMIN Unique trial Number: UMIN000010037.

Regulation of autophagy of the heart in ischemia and reperfusion

Ischemia/reperfusion (I/R) of the heart leads to increased autophagic flux. Preconditioning stimulates autophagic flux by AMPK and PI3-kinase activation and mTOR inhibition. The cardioprotective effect of postconditioning is associated with activation of autophagy and increased activity of NO-synthase and AMPK. Oxidative stress stimulates autophagy in the heart during I/R. Superoxide radicals generated by NADPH-oxidase acts as a trigger for autophagy, possibly due to AMPK activation. There is reason to believe that AMPK, GSK-3β, PINK1, JNK, hexokinase II, MEK, PKCα, and ERK kinases stimulate autophagy, while mTOR, PKCδ, Akt, and PI3-kinase can inhibit autophagy in the heart during I/R. However, there is evidence that PI3-kinase could stimulate autophagy in ischemic preconditioning of the heart. It was found that transcription factors FoxO1, FoxO3, NF-κB, HIF-1α, TFEB, and Nrf-2 enhance autophagy in the heart in I/R. Transcriptional factors STAT1, STAT3, and p53 inhibit autophagy in I/R. MicroRNAs could stimulate and inhibit autophagy in the heart in I/R. Long noncoding RNAs regulate the viability and autophagy of cardiomyocytes in hypoxia/reoxygenation (H/R). Nitric oxide (NO) donors and endogenous NO could activate autophagy of cardiomyocytes. Activation of heme oxygenase-1 promotes cardiomyocyte tolerance to H/R and enhances autophagy. Hydrogen sulfide increases cardiac tolerance to I/R and inhibits apoptosis and autophagy via mTOR and PI3-kinase activation.

Development of cardioprotective effect of chronic continuous hypoxia in rats with induced metabolic syndrome

   Background. It is known that adaptation to chronic continuous hypoxia leads to a pronounced cardioprotective effect. The efficiency of acute adaptation to hypoxia is reduced in metabolic syndrome. However, the effectiveness of the myocardial infarct size-limiting effect of chronic continuous hypoxia in metabolic syndrome remains an understudied fact.   The aim. To study the effectiveness of the development of the myocardial infarct size-limiting effect of chronic continuous hypoxia in rats with metabolic syndrome.   Materials and methods. The study was carried out on 43 Wistar rats. Adaptation of animals to chronic hypoxia was performed during 21 days in a hypoxic chamber (12 % O2, 0.3 % CO2). Metabolic syndrome was modeled by keeping rats on a high-carbohydrate and high-fat diet (proteins 16 %, fats 21 %, carbohydrates 46 % (including fructose 17 %), cholesterol 0.125 %, cholic acid 0.5 %) for 12 weeks with replacement of drinking water with 20% fructose solution. Coronary occlusion-reperfusion was performed in vivo. The effect of chronic hypoxia and metabolic syndrome on myocardial infarct size was assessed.   Results. It was found that myocardial infarct size in rats after chronic continuous hypoxia was 38 % less than in animals of the control group. In rats which were kept on a high-carbohydrate and high-fat diet we observed the obesity, decreased glucose tolerance, increased serum triglycerides level, and hypertension. Adaptation to chronic continuous hypoxia in animals on a high-carbohydrate and high-fat diet improved carbohydrate metabolism, but did not affect the severity of other metabolic disorders. At the same time, the myocardial infarct size-limiting effect of chronic hypoxia was not observed in rats with metabolic syndrome.   Conclusion. Metabolic syndrome eliminated myocardial infarct size-limiting effect of chronic continuous hypoxia.

The risk score for in-hospital mortality in patients with ST-segment elevation myocardial infarction

Aim    To develop a scale (score system) for predicting the individual risk of in-hospital death in patients with ST segment elevation acute myocardial infarction (STEMI) with an account of results of percutaneous coronary intervention (PCI).Material and methods    The analysis used data of 1 649 sequential patients with STEMI included into the hospital registry of PCI from 2006 through 2017. To test the model predictability, the original sample was divided into two groups: a training group consisting of 1150 (70 %) patients and a test group consisting of 499 (30 %) patients. The training sample was used for computing an individual score. To this purpose, β-coefficients of each variable obtained at the last stage of the multivariate logistic regression model were subjected to linear transformation. The scale was verified using the test sample.Results    Seven independent predictors of in-hospital death were determined: age ≥65 years, acute heart failure (Killip class III-IV), total myocardial ischemia time ≥180 min, anterior localization of myocardial infarction, failure of PCI, SYNTAX scale score ≥16, glycemia on admission ≥7.78 mmol/l for patients without a history of diabetes mellitus and ≥14.35 mmol/l for patients with a history of diabetes mellitus. The contribution of each value to the risk of in-hospital death was ranked from 0 to 7. A threshold total score of 10 was determined; a score ≥10 corresponded to a high probability of in-hospital death (18.2 %). In the training sample, the sensitivity was 81 %, the specificity was 80.6 %, and the area under the curve (AUC) was 0.902. In the test sample, the sensitivity was 96.2 %, the specificity was 83.3 %, and the AUC was 0.924.Conclusion    The developed scale has a good predictive accuracy in identifying patients with acute STEMI who have a high risk of fatal outcome at the hospital stage.