High-risk non-ST-segment elevation myocardial infarction versus ST-segment elevation myocardial infarction: same behaviour and outcome?

Calcium signaling from sarcoplasmic reticulum and mitochondria contact sites in acute myocardial infarction

Acute myocardial infarction (AMI) is a serious condition that occurs when part of the heart is subjected to ischemia episodes, following partial or complete occlusion of the epicardial coronary arteries. The resulting damage to heart muscle cells have a significant impact on patient's health and quality of life. About that, recent research focused on the role of the sarcoplasmic reticulum (SR) and mitochondria in the physiopathology of AMI. Moreover, SR and mitochondria get in touch each other through multiple membrane contact sites giving rise to the subcellular region called mitochondria-associated membranes (MAMs). MAMs are essential for, but not limited to, bioenergetics and cell fate. Disruption of the architecture of these regions occurs during AMI although it is still unclear the cause-consequence connection and a complete overview of the pathological changes; for sure this concurs to further damage to heart muscle. The calcium ion (Ca2+) plays a pivotal role in the pathophysiology of AMI and its dynamic signaling between the SR and mitochondria holds significant importance. In this review, we tried to summarize and update the knowledge about the roles of these organelles in AMI from a Ca2+ signaling point of view. Accordingly, we also reported some possible cardioprotective targets which are directly or indirectly related at limiting the dysfunctions caused by the deregulation of the Ca2+ signaling.

Adverse Drug Effect Profiles of Gp2b/3a Inhibitors: A Comparative Review of the Last Two Decades

ST-Elevation Myocardial Infarction and non-ST Elevation Myocardial Infarction belong to the acute coronary syndrome group of diseases. These conditions are characterized by the complete or partial blockage of one or several coronary arteries, resulting in myocardial injury or necrosis. Various medications are used in their treatment, with the most recent addition being Glycoprotein IIb/IIIa inhibitors. They work by hindering the activity of glycoprotein IIb/IIIa receptors, which, in turn, prevents the clumping of platelets. Some of the GpIIb/IIIa inhibitors available in this category include abciximab, tirofiban, eptifibatide, roxifiban, and orbofiban. With this comprehensive literature review, we aimed to explore the potential adverse effects of these medications and compare the three in terms of their side effects profile. We searched through PubMed and Google Scholar and pinpointed 13 articles aligned with our inclusion criteria: six articles utilized eptifibatide, four were related to abciximab, and three used tirofiban. In 85% of the cases, a severe drop in platelet count, reaching as low as 1000/μL, was reported. Additionally, several other side effects were noted: one case documented multiple bruising spots appearing around the patient's body, two cases reported diffuse alveolar hemorrhage, and one case described a cardiac tamponade resulting from hemorrhagic pericarditis. Our study highlights the crucial significance of keeping a watchful eye on and comprehending the potential drawbacks linked to these medications in cardiovascular treatment. The necessity of researching these medications and their side effects is also evident, as this will significantly enhance the quality of treatment provided.

Determinants of Slow Flow in Percutaneous Coronary Intervention to the Culprit Lesion of Non-ST Elevation Myocardial Infarction

Slow flow is a serious complication in percutaneous coronary intervention (PCI) and is associated with poor clinical outcomes. Our previous study revealed that the ratio of stent diameter to vessel diameter was the determinant of slow flow in intravascular ultrasound (IVUS)-guided PCI to the culprit lesion of ST elevation myocardial infarction (STEMI). The purpose of this study was to verify whether the ratio of stent diameter to vessel diameter is the determinant of slow flow in IVUS-guided PCI to the culprit lesion of non-STEMI (NSTEMI). We included 150 NSTEMI patients and divided into the slow flow group (n = 17) and the non-slow flow group (n = 133). The ratio of stent diameter to vessel diameter was significantly larger in the slow flow group (0.77 ± 0.11) than the non-slow flow group (0.71 ± 0.11) (P = 0.03). Multivariate logistic regression analysis revealed that the ratio of stent diameter to vessel diameter (per 0.1 increase: OR 2.06, 95% CI 1.23-3.46, P = 0.006) was the determinant of slow flow after controlling covariates. In conclusion, the ratio of stent diameter to vessel diameter was the determinant of slow flow in IVUS-guided PCI to the culprit lesion of NSTEMI. Unlike other parameters, the ratio of stent diameter to vessel diameter is the modifiable parameters. We may consider the modest stent expansion strategy rather than the aggressive stent expansion strategy in IVUS-guided PCI to the culprit lesion of NSTEMI.

The role of air pollution on ST-elevation myocardial infarction: a narrative mini review

ST-elevation myocardial infarction (STEMI) is one of the potential causes of death worldwide. In spite of substantial advances in its diagnosis and treatment, STEMI is still considered as a major public health dilemma in developed and particularly developing countries. One of the triggering factors of STEMI is supposed to be air pollutants like gaseous pollutants including, sulfur dioxide, nitric dioxide, carbon monoxide, ozone and particulate matters (PM) including, PM under 2.5 µm (PM_2.5) and PM under 10 µm (PM₁₀). Air pollution can trigger STEMI with various mechanisms such as increasing inflammatory factors and changing the heart rate or blood viscosity. In this article, we aimed to explore research in the field and discuss the relationship between air pollution and STEMI.

The association between exposure to air pollutants including PM10, PM2.5, ozone, carbon monoxide, sulfur dioxide, and nitrogen dioxide concentration and the relative risk of developing STEMI: A case-crossover design

BACKGROUND

Unfavorable associations between air pollution and myocardial infarction are broadly investigated in recent studies and some of them revealed considerable associations; however, controversies exists between these investigations with regard to culprit components of air pollution and significance of correlation between myocardial infarction risk and air pollution.

METHODS

The association between exposure to PM₁₀, PM_2.5, ozone, carbon monoxide, sulfur dioxide, and nitrogen dioxide concentration of background air that residents of Tehran, the capital city of Iran, which is ranked as the most air polluted city of Iran and the relative risk of developing ST-elevation myocardial infarction (STEMI) were investigated by a case-crossover design. Our study included 208 patients admitted with a diagnosis of STEMI and undergone primary percutaneous intervention. Air pollutant concentration was averaged in 24-h windows preceding the time of onset of myocardial infarction for the case period. Besides, the mean level of each element of air pollution of the corresponding time in one week, two weeks and three weeks before onset of myocardial infarction, was averaged separately for each day as one control periods. Thus, 624 control periods were included in our investigation such that. Each patient is matched and compared with him/herself.

RESULTS

The mean level of PM₁₀ in case periods (61.47µg/m³) was significantly higher than its level in control periods (57.86µg/m³) (P-value = 0.019, 95% CI: 1.002-1.018, RR = 1.010). Also, the mean level of PM_2.5 in case periods (95.40µg/m³) was significantly higher than that in control days (90.88µg/m³) (P-value = 0.044, 95% CI: 1.001-1.011, RR = 1.006). The level of other components including NO₂, SO₂, CO and O₃ showed no significant differences between case and control periods. A 10µg/m³ increase in PM₁₀ and PM_2.5 would result in 10.10% and 10.06% increase in STEMI event, respectively. Furthermore, the results of sub-group analysis showed that older patients (equal or more than 60 year-old), diabetic patients, non-hypertensive ones and patients with more than one diseased vessel may be more vulnerable to the harmful effect of particular matters including PM₁₀ and PM_2.5 on development of STEMI.

CONCLUSION

Air pollution is a worldwide pandemic with great potential to cause terrible events especially cardiovascular ones. PM_2.5 and PM₁₀ are amongst ambient air pollutant with a high risk of developing STEMI. Thus, more restrictive legislations should be applied to define a safe level of indoor and outdoor air pollutant production.

Autologous Bone Marrow Stem Cell Therapy in Patients With ST-Elevation Myocardial Infarction: A Systematic Review and Meta-analysis

BACKGROUND

Randomized controlled trials (RCTs) on bone marrow stem cell (BMSC) therapy in ST-elevation myocardial infarction (STEMI) patients have reported conflicting results. Our main objective was to critically appraise and meta-analyze best-available evidence on efficacy and safety of intracoronary administration of autologous BMSC therapy in STEMI patients after primary percutaneous coronary intervention.

METHODS

We conducted a search of MEDLINE, PubMed, EMBASE, CENTRAL, Global Health, CINAHL, and conference proceedings in February 2017. Our primary outcome was all-cause mortality. Secondary and safety outcomes included cardiac death, heart failure, arrhythmias, repeat myocardial infarction, or target vessel revascularizations; or improved health-related quality of life, left ventricular ejection fraction, or infarct size. Summary relative and absolute risks were obtained using random effects models. We also evaluated the strength of evidence.

RESULTS

A comprehensive database search identified 42 RCTs (3365 STEMI patients). BMSC therapy did not significantly decrease mortality (risk ratio, 0.71; 95% confidence interval, 0.45-1.11; I², 0%; absolute risk reduction, 0.1%; 95% confidence interval, -0.71 to 0.91; 40 trials; 3289 participants; I², 0%; low strength of evidence). BMSC therapy had no effect on secondary or adverse outcomes. Trial sequential analysis for all-cause mortality showed no evidence of a clinically important difference, with a very low probability that future studies can change the current conclusion.

CONCLUSIONS

On the basis of evidence from 42 RCTs published in the past 15 years, we provide conclusive evidence for a lack of beneficial effect for autologous BMSC therapy in patients with STEMI.

Association of the genetic and traditional risk factors of ischaemic heart disease with STEMI and NSTEMI development

INTRODUCTION

To evaluate the influence of traditional risk factors of ischaemic heart disease and genetic factors to predict different types of acute coronary syndromes.

MATERIALS AND METHODS

Five hundred and twenty-three patients with acute coronary syndromes (393 with ST elevation myocardial infarction (STEMI) and 130 with non-ST elevation myocardial infarction (NSTEMI)) comprised the study group. The control group consisted of 645 subjects free from symptoms of ischaemic heart disease and stroke. Genetic polymorphisms of MMP-2 (-735) C/T, MMP-2 (-1306) C/T, MMP-3 (-1171) 5A/6A, MMP-9 (-1562) C/T and ACE I/D were evaluated using polymerase chain reaction.

RESULTS

Patients with acute coronary syndromes more often had ID or II genotype than DD genotype of ACE ( P = 0.04) and 5A5A or 5A6A genotype than 6A6A genotype of MMP-3 ( P = 0.02) in comparison to the control group. The genotypes of other matrix metalloproteinase genes did not differ between the groups. 5A5A and 5A6A genotypes of MMP-3 (odds ratio (OR) 1.5; P = 0.021), II and ID genotypes of ACE (OR 1.7; P = 0.006) along with traditional ischaemic heart disease risk factors such as smoking (OR 4.9; P = 0.001), hypertension (OR 2.0; P = 0.001), diabetes mellitus (OR 2.9; P = 0.001) and dyslipidaemia (OR 2.1; P = 0.001) increased the risk of STEMI. However, the polymorphism of MMP-3 5A/6A and ACE I/D was not associated with the occurrence of NSTEMI.

CONCLUSIONS

Genetic polymorphisms of MMP-3 5A/6A and ACE I/D along with conventional ischaemic heart disease risk factors increase the risk of the occurrence of STEMI, while having no influence on the pathogenesis of NSTEMI.

Epidemiology of Atherosclerosis and the Potential to Reduce the Global Burden of Atherothrombotic Disease

Atherosclerosis is a leading cause of vascular disease worldwide. Its major clinical manifestations include ischemic heart disease, ischemic stroke, and peripheral arterial disease. In high-income countries, there have been dramatic declines in the incidence and mortality from ischemic heart disease and ischemic stroke since the middle of the 20th century. For example, in the United Kingdom, the probability of death from vascular disease in middle-aged men (35-69 years) has decreased from 22% in 1950 to 6% in 2010. Most low- and middle-income countries have also reported declines in mortality from stroke over the last few decades, but mortality trends from ischemic heart disease have been more varied, with some countries reporting declines and others reporting increases (particularly those in Eastern Europe and Asia). Many major modifiable risk factors for atherosclerosis have been identified, and the causal relevance of several risk factors is now well established (including, but not limited to, smoking, adiposity, blood pressure, blood cholesterol, and diabetes mellitus). Widespread changes in health behaviors and use of treatments for these risk factors are responsible for some of the dramatic declines in vascular mortality in high-income countries. In order that these declines continue and are mirrored in less wealthy nations, increased efforts are needed to tackle these major risk factors, particularly smoking and the emerging obesity epidemic.

Ambient fine particulate air pollution triggers ST-elevation myocardial infarction, but not non-ST elevation myocardial infarction: a case-crossover study

Background

We and others have shown that increases in particulate air pollutant (PM) concentrations in the previous hours and days have been associated with increased risks of myocardial infarction, but little is known about the relationships between air pollution and specific subsets of myocardial infarction, such as ST-elevation myocardial infarction (STEMI) and non ST-elevation myocardial infarction (NSTEMI).

Methods

Using data from acute coronary syndrome patients with STEMI (n = 338) and NSTEMI (n = 339) and case-crossover methods, we estimated the risk of STEMI and NSTEMI associated with increased ambient fine particle (<2.5 um) concentrations, ultrafine particle (10-100 nm) number concentrations, and accumulation mode particle (100-500 nm) number concentrations in the previous few hours and days.

Results

We found a significant 18% increase in the risk of STEMI associated with each 7.1 μg/m³ increase in PM_2.5 concentration in the previous hour prior to acute coronary syndrome onset, with smaller, non-significantly increased risks associated with increased fine particle concentrations in the previous 3, 12, and 24 hours. We found no pattern with NSTEMI. Estimates of the risk of STEMI associated with interquartile range increases in ultrafine particle and accumulation mode particle number concentrations in the previous 1 to 96 hours were all greater than 1.0, but not statistically significant. Patients with pre-existing hypertension had a significantly greater risk of STEMI associated with increased fine particle concentration in the previous hour than patients without hypertension.

Conclusions

Increased fine particle concentrations in the hour prior to acute coronary syndrome onset were associated with an increased risk of STEMI, but not NSTEMI. Patients with pre-existing hypertension and other cardiovascular disease appeared particularly susceptible. Further investigation into mechanisms by which PM can preferentially trigger STEMI over NSTEMI within this rapid time scale is needed.

Optimal timing of coronary artery bypass grafting in acute myocardial infarction

The timing of surgical coronary artery revascularization after an acute myocardial infarction is not well defined. The inherent difficulties of mobilizing a surgical team at odd hours has led to the adoption of a percutaneous coronary intervention strategy when possible or a clot-busting drug regimen when percutaneous coronary intervention is not available. Despite the difficulties and risks of surgical revascularization, there are situations where it may be indicated. We conducted a review of the literature to better understand the timing, scope, and risks of surgical coronary revascularization after an acute myocardial infarction.

Diagnostic accuracy of heart fatty acid binding protein (H-FABP) and glycogen phosphorylase isoenzyme BB (GPBB) in diagnosis of acute myocardial infarction in patients with acute coronary syndrome

INTRODUCTION

This study aimed to assess whether heart fatty acid-binding protein (H-FABP) and glycogen phosphorylase isoenzyme BB (GPBB) could be used for the accurate diagnosis of acute myocardial infarction (AMI) in acute coronary syndrome (ACS) patients.

MATERIALS AND METHODS

The study included 108 ACS patients admitted to a coronary unit within 3 h after chest pain onset. AMI was distinguished from unstable angina (UA) using a classical cardiac troponin I (cTnI) assay. H-FABP and GPBB were measured by ELISA on admission (0 h) and at 3, 6, 12, and 24 h after admission; their accuracy to diagnose AMI was assessed using statistical methods.

RESULTS

From 92 patients with ACS; 71 had AMI. H-FABP and GPBB had higher peak value after 3 h from admission than cTnI (P = 0.001). Both markers normalized at 24 h. The area under the receiver operating characteristic curves was significantly greater for both markers in AMI patients than in UA patients at all time points tested, including admission (P < 0.001). At admission, the H-FABP (37%) and GPBB (40%) sensitivities were relatively low. They increased at 3 and 6 h after admission for both markers and decreased again after 24 h. It was 40% for H-FABP and approximately 2-times lower for GPBB (P < 0.01). In AMI patients, both biomarkers had similar specificities, positive- and negative-predictive values, positive and negative likelihood ratios, and risk ratios for AIM.

CONCLUSION

H-FABP and GPBB can contribute to early AMI diagnosis and can distinguish AMI from UA.

Perforin-mediated cytotoxicity in non-ST elevation myocardial infarction

The aim of this investigation was to examine the role of perforin (P)-mediated cytotoxicity in the dynamics of tissue damage in patients with non-ST-segment elevation myocardial infarction (NSTEMI) treated with anti-ischaemic drugs. We enrolled 48 patients with NSTEMI in this study [age, 71.5 years; 61.5/76 (median, 25th/75th percentiles)]. The percentage of total peripheral blood P(+) lymphocytes was elevated owing to the increased frequency of P(+) cells within natural killer (NK) subsets, T and NKT cells in patients on day 1 after NSTEMI when compared with healthy controls. Positive correlations were found between cardiac troponin I plasma concentrations and the frequency of P(+) cells, P(+) T cells, P(+) NK cells and their CD56(+dim) and CD56(+bright) subsets during the first week after the NSTEMI. The expression of P in NK cells was accompanied by P-mediated cytotoxicity against K-562 targets at all days examined, except day 21, when an anti-perforin monoclonal antibody did not completely abolish the killing. The percentage of P(+) T cells, P(+) NKT cells and P(+) NK subsets was the highest on the day 1 after NSTEMI and decreased in the post-infarction period. CD56(+) lymphocytes were found in damaged myocardium, suggesting their tissue recruitment. In conclusion, patients with NSTEMI have a strong and prolonged P-mediated systemic inflammatory reaction, which may sustain autoaggressive reactions towards myocardial tissue during the development of myocardial infarction.