Predictors of infarct size after primary coronary angioplasty in acute myocardial infarction from pooled analysis from four contemporary trials

ALDH2 polymorphism and myocardial infarction: From alcohol metabolism to redox regulation

Acute myocardial infarction (AMI) remains a leading cause of death worldwide. Increased formation of reactive oxygen species (ROS) during the early reperfusion phase is thought to trigger lipid peroxidation and disrupt redox homeostasis, leading to myocardial injury. Whilst the mitochondrial enzyme aldehyde dehydrogenase 2 (ALDH2) is chiefly recognised for its central role in ethanol metabolism, substantial experimental evidence suggests an additional cardioprotective role for ALDH2 independent of alcohol intake, which mitigates myocardial injury by detoxifying breakdown products of lipid peroxidation including the reactive aldehydes, malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE). Epidemiological evidence suggests that an ALDH2 mutant variant with reduced activity that is highly prevalent in the East Asian population increases AMI risk. Additional studies have uncovered a strong association between coronary heart disease and this ALDH2 mutant variant. It appears this enzyme polymorphism (in particular, in ALDH2*2/2 carriers) has the potential to have wide-ranging effects on thiol reactivity, redox tone and therefore numerous redox-related signaling processes, resilience of the heart to cope with lifestyle-related and environmental stressors, and the ability of the whole body to achieve redox balance. In this review, we summarize the journey of ALDH2 from a mitochondrial reductase linked to alcohol metabolism, via pre-clinical studies aimed at stimulating ALDH2 activity to reduce myocardial injury to clinical evidence for its protective role in the heart.

Cardiogenic shock complicating acute myocardial infarction and multivessel disease: revascularization strategy according to ischemic territory

INTRODUCTION AND OBJECTIVES

The association of revascularization strategy with clinical outcomes according to the ischemic territory of nonculprit lesion has not been documented in patients with acute myocardial infarction complicated by cardiogenic shock (AMI-CS). This study aimed to compare outcomes between culprit-only and immediate multivessel percutaneous coronary intervention (PCI) according to ischemic territory in patients with AMI-CS.

METHODS

A total of 536 patients with AMI-CS and multivessel disease from the SMART-RESCUE registry were categorized according to ischemic territory (nonculprit left main/proximal left anterior descending artery [LM/pLAD] vs culprit LM/pLAD vs no LM/pLAD). The primary outcome was a patient-oriented composite endpoint (POCE) consisting of all-cause death, myocardial infarction, rehospitalization due to heart failure, or repeat revascularization at 1 year.

RESULTS

Among the total population, 108 patients had nonculprit LM/pLAD, 228 patients had culprit LM/pLAD, and 200 patients had no LM/pLAD, with the risk of POCE being higher in patients with large ischemic territory lesions (53.6% vs 53.4% vs 39.6%; P = .02). Multivessel PCI was associated with a significantly lower risk of POCE compared with culprit-only PCI in patients with nonculprit LM/pLAD (40.7% vs 66.9%; HR, 0.52; 95%CI, 0.29-0.91; P=.02), but not in those with culprit LM/pLAD (P=.46) or no LM/pLAD (P=.47). A significant interaction existed between revascularization strategy and large nonculprit ischemic territory (P=.03).

CONCLUSIONS

Large ischemic territory involvement was associated with worse clinical outcomes in patients with AMI-CS and multivessel disease. Immediate multivessel PCI might improve clinical outcomes in patients with a large nonculprit ischemic burden.

Prehospital crushed versus integral prasugrel loading dose in STEMI patients with a large myocardial area

BACKGROUND

The effect of administering a crushed prasugrel loading dose is uncertain in patients presenting with a large myocardial infarction and ST-segment elevation myocardial infarction (STEMI).

AIMS

The aim of this study was to investigate if patients with a large myocardial infarction may benefit from prehospital administration of a crushed prasugrel loading dose.

METHODS

Patients from the CompareCrush trial with an available ambulance electrocardiography (ECG) were included in the study. An independent core laboratory confirmed a prehospital large myocardial area. We compared pre- and postprocedural angiographic markers, including Thrombolysis in Myocardial Infarction (TIMI) 3 flow in the infarct-related artery, high thrombus burden, and myocardial blush grade 3, in STEMI patients with and without a prehospital large myocardial area.

RESULTS

Ambulance ECG was available for 532 patients, of whom 331 patients were identified with a prehospital large myocardial area at risk. Crushed prasugrel significantly improved postprocedural TIMI 3 flow rates in STEMI patients with a prehospital large myocardial area at risk (92% vs 79%, odds ratio [OR] 3.00, 95% confidence interval [CI]: 1.50-6.00) but not in STEMI patients without a prehospital large myocardial area at risk (91% vs 95%, OR 0.47, 95% CI: 0.14-1.57; pinteraction=0.009).

CONCLUSIONS

Administration of crushed prasugrel may improve postprocedural TIMI 3 flow in STEMI patients with signs of a large myocardial area at risk on the ambulance ECG. The practice of crushing tablets of prasugrel loading dose might, therefore, represent a safe, fast and cost-effective strategy to improve myocardial reperfusion in this high-risk STEMI subgroup undergoing primary percutaneous coronary intervention.

Circulating GDF11 exacerbates myocardial injury in mice and associates with increased infarct size in humans

AIMS

The heart rejuvenating effects of circulating growth differentiation factor 11 (GDF11), a transforming growth factor-β superfamily member that shares 90% homology with myostatin (MSTN), remains controversial. Here, we aimed to probe the role of GDF11 in acute myocardial infarction (MI), a frequent cause of heart failure and premature death during ageing.

METHODS AND RESULTS

In contrast to endogenous Mstn, myocardial Gdf11 declined during the course of ageing and was particularly reduced following ischaemia/reperfusion (I/R) injury, suggesting a therapeutic potential of GDF11 signalling in MI. Unexpectedly, boosting systemic Gdf11 by recombinant GDF11 delivery (0.1 mg/kg body weight over 30 days) prior to myocardial I/R augmented myocardial infarct size in C57BL/6 mice irrespective of their age, predominantly by accelerating pro-apoptotic signalling. While intrinsic cardioprotective signalling pathways remained unaffected by high circulating GDF11, targeted transcriptomics and immunomapping studies focusing on GDF11-associated downstream targets revealed attenuated Nkx2-5 expression confined to CD105-expressing cells, with pro-apoptotic activity, as assessed by caspase-3 levels, being particularly pronounced in adjacent cells, suggesting an indirect effect. By harnessing a highly specific and validated liquid chromatography-tandem mass spectrometry-based assay, we show that in prospectively recruited patients with MI circulating GDF11 but not MSTN levels incline with age. Moreover, GDF11 levels were particularly elevated in those at high risk for adverse outcomes following the acute event, with circulating GDF11 emerging as an independent predictor of myocardial infarct size, as estimated by standardized peak creatine kinase-MB levels.

CONCLUSION

Our data challenge the initially reported heart rejuvenating effects of circulating GDF11 and suggest that high levels of systemic GDF11 exacerbate myocardial injury in mice and humans alike. Persistently high GDF11 levels during ageing may contribute to the age-dependent loss of cardioprotective mechanisms and thus poor outcomes of elderly patients following acute MI.

Cardioprotective Role of Swertiamarin, a Plant Glycoside Against Experimentally Induced Myocardial Infarction via Antioxidant and Anti-inflammatory Functions

The study examined the protective effects of swertiamarin on rats with experimentally induced myocardial infarction. Three to six week-old male albino Wistar rats were used in this study and experimental myocardial infarction (MI) was induced using isoproterenol. Our results showed that swertiamarin restored the alteration in heart weight, body weight, and heart weight/tibia length ratio of MI-induced rats to basal levels significantly (p < 0.05). Swertiamarin significantly (p < 0.05) restored the levels of cardiac pathophysiological marker creatine kinase (CKMB), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), alanine transaminase (ALT), and cardiac troponin I (cTn-1) to near normalcy in MI-induced rats. Levels of oxidative stress markers malondialdehyde (MDA), protein carbonyls (PC), and levels of Vitamin C and Vitamin E were significantly (p < 0.05) reverted to near basal levels in MI-induced rats by swertiamarin. Levels of the antioxidant glutathione (GSH) and antioxidant enzymes which include superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-s-transferase (GST), glutathione reductase (GR), and plasma total antioxidant capacity (TAC) were (p < 0.05) brought to near normalcy in MI-induced rats by swertiamarin. Levels of sodium (Na), potassium (k), and calcium (Ca) ATPases were significantly (p < 0.05) restored to near normalcy in MI-induced rats by swertiamarin. Status of pro-inflammatory cytokines including tumor necrosis factor (TNF-α), interleukin-6 (IL-6), and histological aberrations were also significantly (p < 0.05) restored to near normalcy in MI-induced rats by swertiamarin. Together, our results concluded that swertiamarin exerts significant cardioprotective functions in experimental MI in rats.

Nomograms referenced by cardiac magnetic resonance in the prediction of cardiac injuries in patients with ST-elevation myocardial infarction

BACKGROUND

Evaluation of cardiac injuries is essential in patients with ST-elevation myocardial infarction (STEMI). Cardiac magnetic resonance (CMR) has become the gold standard for quantifying cardiac injuries; however, its routine application is limited. A nomogram is a useful tool for prognostic prediction based on the comprehensive utilization of clinical data. We presumed that the nomogram models established using CMR as a reference could precisely predict cardiac injuries.

METHODS

This analysis included 584 patients with acute STEMI from a CMR registry study for STEMI (NCT03768453). The patients were divided into training (n = 408) and testing (n = 176) datasets. The least absolute shrinkage and selection operator method and multivariate logistic regression were used to construct nomograms for predicting left ventricular ejection fraction (LVEF) ≤40%, infarction size (IS) ≥ 20% on the LV mass, and microvascular dysfunction.

RESULTS

The nomogram for predicting LVEF≤40%, IS≥20%, and microvascular dysfunction comprised 14, 10, and 15 predictors, respectively. With the nomograms, the individual risk probability of developing specific outcomes could be calculated, and the weight of each risk factor was demonstrated. The C-index of the nomograms in the training dataset were 0.901, 0.831, and 0.814, respectively, and were comparable in the testing set, showing good nomogram discrimination and calibration. The decision curve analysis demonstrated good clinical effectiveness. Online calculators were also constructed.

CONCLUSIONS

With the CMR results as the reference standard, the established nomograms demonstrated good effectiveness in predicting cardiac injuries after STEMI and could provide physicians with a new option for individual risk stratification.

Machine learning-based prediction of infarct size in patients with ST-segment elevation myocardial infarction: A multi-center study

BACKGROUND

Cardiac magnetic resonance imaging (CMR) is the gold standard for measuring infarct size (IS). However, this method is expensive and requires a specially trained technologist to administer. We therefore sought to quantify the IS using machine learning (ML) based analysis on clinical features, which is a convenient and cost-effective alternative to CMR.

METHODS AND RESULTS

We included 315 STEMI patients with CMR examined one week after morbidity in final analysis. After feature selection by XGBoost on fifty-six clinical features, we used five ML algorithms (random forest (RF), light gradient boosting decision machine, deep forest, deep neural network, and stacking) to predict IS with 26 (selected by XGBoost with information gain greater than average level of 56 features) and the top 10 features, during which 5-fold cross-validation were used to train and optimize models. We then evaluated the value of actual and ML-IS for the prediction of adverse remodeling. Our finding indicates that MLs outperform the linear regression in predicting IS. Specifically, the RF with five predictors identified by the exhaustive method performed better than linear regression (LR) with 10 indicators (R² of RF: 0.8; LR: 0). The finding also shows that both actual and ML-IS were independently associated with adverse remodeling. ML-IS ≥ 21% was associated with a twofold increase in the risk of LV remodeling (P < 0.01) compared with patients with reference IS (1st tertile).

CONCLUSION

ML-based methods can predict IS with widely available clinical features, which provide a proof-of-concept tool to quantitatively assess acute phase IS.

Characteristics, Process Metrics, and Outcomes Among Patients With ST-Elevation Myocardial Infarction in Rural vs Urban Areas in the US: A Report From the US National Cardiovascular Data Registry

Importance

Patients with ST-segment elevation myocardial infarction (STEMI) living in rural settings often have worse clinical outcomes compared with their urban counterparts. Whether this discrepancy is due to clinical characteristics or delays in timely reperfusion with primary percutaneous coronary intervention (PPCI) or fibrinolysis is unclear.

Objective

To assess process metrics and outcomes among patients with STEMI in rural and urban settings across the US.

Design, Setting, and Participants

This cross-sectional multicenter study analyzed data for 70 424 adult patients with STEMI from the National Cardiovascular Data Registry Chest Pain-MI Registry in 686 participating US hospitals between January 1, 2019, and June 30, 2020. Patients without a valid zip code were excluded, and those transferred to a different hospital during the course of the study were excluded from outcome analysis.

Main Outcomes and Measures

In-hospital mortality and time-to-reperfusion metrics.

Results

This study included 70 424 patients with STEMI (median [IQR] age, 63 [54-73] years; 49 850 [70.8%] male and 20 574 [29.2%] female; patient self-reported race: 6753 [9.6%] Black, 60 114 [85.4%] White, and 2096 [3.0%] of another race [including American Indian, Alaskan Native, Native Hawaiian, and Pacific Islander]; 5281 [7.5%] individuals of Hispanic or Latino ethnicity) in 686 hospitals (50 702 [72.0%] living in urban zip codes and 19 722 [28.0%] in rural zip codes). Patients from rural settings were less likely to undergo PPCI compared with patients from urban settings (14 443 [73.2%] vs 43 142 [85.1%], respectively; P < .001) and more often received fibrinolytics (2848 [19.7%] vs 937 [2.7%]; P < .001). Compared with patients from urban settings, those in rural settings undergoing PPCI had longer median (IQR) time from first medical contact to catheterization laboratory activation (30 [12-42] minutes vs 22 [15-59] minutes; P < .001) and longer median (IQR) time from first medical contact to device (99 minutes [75-131] vs 81 [66-103] minutes; P < .001), including those who arrived directly at PPCI centers (83 [66-107] minutes vs 78 [64-97] minutes; P < .001) and those who transferred to PPCI centers from another treatment center (125 [102-163] minutes vs 103 [85-135] minutes; P < .001). Among those who transferred in, median (IQR) door-in-door-out time was longer in patients from rural settings (63 [41-100] minutes vs 50 [35-80] minutes; P < .001). Out-of-hospital cardiac arrest was more common in patients from urban vs rural settings (3099 [6.1%] vs 958 [4.9%]; P < .001), and patients from urban settings were more likely to present with heart failure (4112 [8.1%] vs 1314 [6.7%]; P < .001). After multivariable adjustment, there was no significant difference in in-hospital mortality between rural and urban groups (adjusted odds ratio, 0.97; 95% CI, 0.89-1.06).

Conclusions and Relevance

In this large cohort of patients with STEMI from US hospitals participating in the National Cardiovascular Data Registry Chest Pain-MI Registry, patients living in rural settings had longer times to reperfusion, were less likely to receive PPCI or meet guideline-recommended time to reperfusion, and more frequently received fibrinolytics than patients living in urban settings. However, there was no difference in adjusted in-hospital mortality between patients with STEMI from urban and rural settings.

Intracoronary pharmacological therapy versus aspiration thrombectomy in STEMI (IPAT-STEMI): A systematic review and meta-analysis of randomized trials

BACKGROUND

Thrombus load in STEMI patients remains a challenge in practice. It aggravates coronary obstruction leading to impaired myocardial perfusion, worsened cardiac function, and adverse clinical outcomes. Various strategies have been advocated to reduce thrombus burden.

OBJECTIVES

This meta-analysis aimed to evaluate the effectiveness of intracoronary-administered thrombolytics or glycoprotein IIb/IIIa inhibitors (GPI) in comparison with aspiration thrombectomy (AT) as an adjunct to percutaneous coronary intervention (PCI) among patients presenting with ST-segment elevation myocardial infarction (STEMI).

METHODS

A comprehensive literature search for randomized trials that compared intracoronary-administered thrombolytics or GPI with AT in STEMI patients who underwent PCI, was conducted using various databases (e.g., MEDLINE, EMBASE, CENTRALE). Primary outcome was procedural measures (e.g., TIMI flow grade 3, TIMI myocardial perfusion grade (TMPG) 3, Myocardial blush grade (MBG) 2/3, ST-segment resolution (STR)).

RESULTS

Twelve randomized trials enrolled 1,466 patients: 696 were randomized to intracoronary-administered pharmacological interventions and 553 to AT. Patients randomized to PCI alone were excluded. Thrombolytics significantly improved TIMI flow grade 3 (odds ratio = 3.71, 95% CI: 1.85-7.45), complete STR (odds ratio = 3.64, 95% CI: 1.60-8.26), and TMPG 3 (odds ratio = 5.31, 95% CI: 2.48-11.36). Thrombolytics significantly reduced major adverse cardiovascular events (MACE) (odds ratio = 0.29, 95% CI: 0.13-0.65) without increasing bleeding risk. Trial sequential analysis assessment confirmed the superiority of thrombolytics for the primary outcome. Intracoronary GPI, either alone or combined with AT, did not improve procedural or clinical outcomes.

CONCLUSIONS

Compared with AT, intracoronary-administered thrombolytics significantly improved myocardial perfusion and MACE in STEMI patients.

Circulating fibrocyte levels correlate with infarct size in patients with ST elevation myocardial infarction treated with primary percutaneous coronary intervention

Study objective:

Infarct size is a strong predictor of outcomes after ST elevation myocardial infarction (STEMI). Circulating fibrocytes are bone marrow-derived progenitor cells associated with fibrotic processes. We tested whether fibrocytes correlate with infarct size in STEMI patients treated with primary percutaneous coronary intervention (PCI).

Design:

Prospective observational study.

Setting:

Academic medical center.

Participants:

Subjects with STEMI treated with primary PCI.

Interventions:

Peripheral blood draw and cardiac magnetic resonance imaging (CMR).

Main outcome measure:

Correlation of fibrocyte levels with infarct size.

Methods:

Peripheral blood fibrocytes were quantified at discharge from STEMI hospitalization and at 6 months follow-up using flow cytometry. Infarct size was determined within 2 weeks of discharge and at 6 months follow-up using late gadolinium enhancement on CMR.

Results:

Among 14 patients (median age 54 years, 79% men) with STEMI, there was a statistically significant positive correlation between fibrocyte levels at 6 months and 6-month infarct size on CMR (r = 0.58, p = 0.031). In addition, there was positive correlation between peak troponin I level (r = 0.85, p < 0.001), and white blood cell count (r = 0.55, p = 0.042) during the hospital stay and 6-month infarct size on CMR.

Conclusions:

Circulating fibrocytes measured 6 months after STEMI positively correlate with 6-month infarct size assessed by CMR.

The Comparing of Short Clinical Cardiovascular Outcomes with Wraparound and Nonwraparound Left Anterior Descending Artery in Patients with Anterior ST-Segment Elevation Myocardial Infarction

Background:

The relation between left anterior descending artery (LAD) anatomy and clinical outcomes in patients with anterior ST-segment elevation myocardial infarction (STEMI) has not been fully investigated. The aim of this study was to determine the frequency and severity of short-term cardiovascular outcomes in patients with Anterior ST-Segment Elevation Myocardial Infarction (STEMI) undergoing primary percutaneous intervention (PCI), based on wraparound and non-wraparound left anterior descending artery (LAD).

Methods:

In a cross-sectional study, 126 patients with anterior STEMI who were admitted to Shahid Chamran Hospital in Isfahan during 2020 were studied. Patients were evaluated for anatomical features of LAD coronary artery and clinical outcomes determined and compared based on wraparound LAD and non-wraparound LAD during hospitalization and up to one month after PCI.

Results:

The prevalence of wraparound LAD in the studied patients was 73% and left ventricular systolic dysfunction in admission was greater and more severe in patients with wraparound LADs compared with those with non-wraparound. Severe LV systolic dysfunction in the wraparound and non-wraparound groups was 39.6% and 8.8%, respectively (P < 0.001). Also, the frequency of arrhythmias in the wraparound group (21.7%) was higher than the non-wraparound group (5.9%) (P = 0.037).

Conclusion:

The patients with anterior STEMI and wraparound LAD have a worse clinical outcome and more severe left ventricular systolic dysfunction. Therefore, it seems that the study of the anatomical condition of the LAD artery at the time of angiography is of great importance in the way of observation and care, and treatment of patients.

Undiagnosed Cardiac Sarcoidosis Causing Refractory Heart Failure After Acute Myocardial Infarction due to Thromboembolism

A 61-year-old woman suffered chest pain and was admitted to a nearby hospital emergency department. She was diagnosed with acute myocardial infarction probably due to thromboembolism in the left anterior descending coronary artery and aspiration thrombectomy was performed. Afterwards, she developed refractory heart failure with severe global left ventricular dysfunction and was transferred to our hospital. An ¹⁸F-FDG-PET/CT scan revealed abnormal ¹⁸F-FDG uptake in non-infarcted regions of the left ventricle. Non-caseating granulomas were detected by biopsy from a skin eruption. She was diagnosed with cardiac sarcoidosis. In cases of refractory heart failure which cannot be explained only by myocardial infarction, evaluation of other undiagnosed cardiomyopathies is important for optimal management.

C-Reactive Protein Apheresis as Anti-inflammatory Therapy in Acute Myocardial Infarction: Results of the CAMI-1 Study

Background: C-reactive protein (CRP) is a well-known marker of inflammation. It is less known that CRP mediates tissue damage in acute myocardial infarction (AMI) thus potentially worsening prognosis. A newly developed specific CRP adsorber allows efficient lowering of CRP levels and may improve survival.

Objectives: Aim of this multi-center, controlled, non-randomized first-in-man CRP apheresis in Acute Myocardial Infarction study (CAMI-1) was to investigate the relationship between CRP levels (CRP gradient), myocardial infarct size and function as well as safety and efficacy of CRP apheresis in the setting of acute ST-segment Elevation Myocardial Infarction (STEMI) in humans.

Methods: Eighty-three patients (45 apheresis, 38 controls) were recruited. CRP apheresis was performed 24 ± 12, 48 ± 12, and optionally 72 ± 12 h after onset of symptoms. First aphereses were performed at a median CRP concentration of 23.0 mg/L (range 9–279). In each apheresis session, 5,900 ± 400 mL plasma was processed via peripheral venous access. Primary study endpoint was a reduction in myocardial infarct size after STEMI as determined by cardiovascular magnetic resonance (CMR).

Results: In controls, the CRP concentration significantly correlated with infarct size (p = 0.002) and decreased myocardial function (p ≤ 0.001). The CRP concentration in apheresis patients did not correlate with infarct size (p = 0.66) or left ventricular (LV) function (p = 0.79) and global strains and therefore significantly differed from controls (p = 0.03 and p = 0.002). Three major adverse cardiac events occurred in the control group after 12 months, none occurred in the apheresis group. Mean CRP depletion achieved over all apheresis procedures was 53.0 ± 15.1%. Apheresis sessions were well-tolerated. Reduced infarct size in the apheresis group compared to the control group (primary endpoint) was not achieved according to the original statistical analysis plan. Taking into account the individual CRP levels, however, revealed significant results. Modifications of the analysis plan were introduced in order to recruit a sufficient number of patients.

Conclusions: This pilot study in humans reveals a correlation between CRP concentration and myocardial infarct size. CRP concentrations in STEMI can effectively be reduced by CRP apheresis without relevant side effects. CRP apheresis has the potential to interfere with deleterious aspects of STEMI. By lowering CRP levels, it resulted in the loss of correlation of CRP concentrations with myocardial infarct sizes as well as LV function. These results encourage a larger, randomized clinical trial.

Clinical Trial Registration:https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00008988, DRKS00008988.

Effect of Smoking on Outcomes of Primary PCI in Patients With STEMI

BACKGROUND

Smoking is a well-established risk factor for ST-segment elevation myocardial infarction (STEMI); however, once STEMI occurs, smoking has been associated with favorable short-term outcomes, an observation termed the "smoker's paradox." It has been postulated that smoking might exert protective effects that could reduce infarct size, a strong independent predictor of worse outcomes after STEMI.

OBJECTIVES

The purpose of this study was to determine the relationship among smoking, infarct size, microvascular obstruction (MVO), and adverse outcomes after STEMI.

METHODS

Individual patient-data were pooled from 10 randomized trials of patients with STEMI undergoing primary percutaneous coronary intervention. Infarct size was assessed at median 4 days by either cardiac magnetic resonance imaging or technetium-99m sestamibi single-photon emission computed tomography. Multivariable analysis was used to assess the relationship between smoking, infarct size, and the 1-year rates of death or heart failure (HF) hospitalization and reinfarction.

RESULTS

Among 2,564 patients with STEMI, 1,093 (42.6%) were recent smokers. Smokers were 10 years younger and had fewer comorbidities. Infarct size was similar in smokers and nonsmokers (adjusted difference: 0.0%; 95% confidence interval [CI]: -3.3% to 3.3%; p = 0.99). Nor was the extent of MVO different between smokers and nonsmokers. Smokers had lower crude 1-year rates of all-cause death (1.0% vs. 2.9%; p < 0.001) and death or HF hospitalization (3.3% vs. 5.1%; p = 0.009) with similar rates of reinfarction. After adjustment for age and other risk factors, smokers had a similar 1-year risk of death (adjusted hazard ratio [adjHR]: 0.92; 95% CI: 0.46 to 1.84) and higher risks of death or HF hospitalization (adjHR: 1.49; 95% CI: 1.09 to 2.02) as well as reinfarction (adjHR: 1.97; 95% CI: 1.17 to 3.33).

CONCLUSIONS

In the present large-scale individual patient-data pooled analysis, recent smoking was unrelated to infarct size or MVO, but was associated with a worse prognosis after primary PCI in STEMI. The smoker's paradox may be explained by the younger age and fewer cardiovascular risk factors in smokers compared with nonsmokers.

Corin Overexpression Reduces Myocardial Infarct Size and Modulates Cardiomyocyte Apoptotic Cell Death

Altered expression of corin, a cardiac transmembrane serine protease, has been linked to dilated and ischemic cardiomyopathy. However, the potential role of corin in myocardial infarction (MI) is lacking. This study examined the outcomes of MI in wild-type vs. cardiac-specific overexpressed corin transgenic (Corin-Tg) mice during pre-MI, early phase (3, 24, 72 h), and late phase (1, 4 weeks) post-MI. Corin overexpression significantly reduced cardiac cell apoptosis (p < 0.001), infarct size (p < 0.001), and inhibited cleavage of procaspases 3, 9, and 8 (p < 0.05 to p < 0.01), as well as altered the expression of Bcl2 family proteins, Bcl-xl, Bcl2 and Bak (p < 0.05 to p < 0.001) at 24 h post-MI. Overexpressed cardiac corin also significantly modulated heart function (ejection fraction, p < 0.0001), lung congestion (lung weight to body weight ratio, p < 0.0001), and systemic extracellular water (edema, p < 0.05) during late phase post-MI. Overall, cardiac corin overexpression significantly reduced apoptosis, infarct size, and modulated cardiac expression of key members of the apoptotic pathway in early phase post-MI; and led to significant improvement in heart function and reduced congestion in late phase post-MI. These findings suggest that corin may be a useful target to protect the heart from ischemic injury and subsequent post-infarction remodeling.

Effect of intracoronary tirofiban following aspiration thrombectomy on infarct size, in patients with large anterior ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention

BACKGROUND

Myocardial recovery following primary percutaneous coronary intervention is often suboptimal despite of restoration of thrombolysis in myocardial infarction (TIMI) 3 flow, in part due to thrombus embolization which results in impairing microvascular reperfusion besides increasing infarct size. The purpose of the present study was to estimate the effect of aspiration thrombectomy followed by intracoronary delivery of tirofiban on decreasing the infarct size utilizing cardiac MRI (cMR) in large anterior ST-segment elevation myocardial infarction (STEMI) patients.

PATIENTS

A prospective randomized controlled study of 100 patients with large anterior STEMI were randomized to (Study group) using intracoronary tirofiban (intracoronary) and (control group) without intocoronary tirofiban. A 6 F thrombus aspiration catheter was used in all patients. Tirofiban was injected locally at the place of the highly thrombus burden through the aspiration device after flushing the aspiration device well.

RESULTS

Patients of intracoronary tirofiban group compared with control group had a significant difference in decreasing the infarct size at 30 days [median, 15.451 g - interquartile range (IQR), 17.404 gm - n = 50] vs (median, 43.828 g - IQR, 49.599 g - n = 50) P value = 0.002.

CONCLUSION

In patients early presented with large anterior STEMI, infarct size at 30 days was significantly decreased by intracoronary tirofiban delivered to the infarct lesion site followed aspiration thrombectomy.

Predictors of mortality in patients with non-anterior ST-segment elevation myocardial infarction: Analysis from the HORIZONS-AMI trial

OBJECTIVES

We sought to identify clinical, electrocardiographic (ECG), and angiographic characteristics that are predictive of 3-year mortality after primary percutaneous coronary intervention (PCI) in patients with non-anterior ST-elevation myocardial infarction (NA-STEMI) from the Harmonizing Outcomes With Revascularization and Stents in Acute Myocardial Infarction (HORIZONS-AMI) trial.

BACKGROUND

Which patients with NA-STEMI undergoing PCI have a poor prognosis is uncertain.

METHODS

NA-STEMI was defined as ST-segment elevation in lateral (V5, V6, I, aVL), inferior (II, III, aVF), or inferolateral (I, II, III, aVF, and V5-V6) ECG leads or posterior myocardial infarction with ST-segment depression of ≥1 mm in ≥2 contiguous anterior leads. Cox regression was used to identify independent predictors of 3-year mortality. Missing data were imputed using multiple imputation.

RESULTS

In HORIZONS-AMI, 2,578/3,602 patients had no prior coronary artery bypass grafting, underwent single-vessel PCI, and had baseline ECG data assessed in an independent core laboratory. Among them, 1,495 (58.0%) had NA-STEMI. Patients with NA-STEMI had lower 3-year mortality risk than those with anterior STEMI (4.5% versus 7.1%, P = 0.004). The independent predictors of increased 3-year mortality in NA-STEMI were older age (median > 59.0 years), diabetes, reduced LVEF (≤50%), Killip class ≥2, post-procedure TIMI flow 0-2 versus 3, renal insufficiency, and ST-resolution <30% at 60 min post-PCI. Patients with 0, 1, 2, 3, and ≥4 of these risk factors had 3-year mortality rates of 1.8%, 2.3%, 3.1%, 6.1%, and 36.3%, respectively (P < 0.0001).

CONCLUSIONS

Although NA-STEMI carries a better prognosis than anterior STEMI, high-risk patient cohorts with NA-STEMI may be identified who have substantial 3-year mortality.

Time-Dependent Myocardial Necrosis in Patients With ST-Segment-Elevation Myocardial Infarction Without Angiographic Collateral Flow Visualized by Cardiac Magnetic Resonance Imaging: Results From the Multicenter STEMI-SCAR Project

Background Acute complete occlusion of a coronary artery results in progressive ischemia, moving from the endocardium to the epicardium (ie, wavefront). Dependent on time to reperfusion and collateral flow, myocardial infarction ( MI ) will manifest, with transmural MI portending poor prognosis. Late gadolinium enhancement cardiac magnetic resonance imaging can detect MI with  high diagnostic accuracy. Primary percutaneous coronary intervention is the preferred reperfusion strategy in patients with ST -segment-elevation MI with <12 hours of symptom onset. We sought to visualize time-dependent necrosis in a population with ST -segment-elevation MI by using late gadolinium enhancement cardiac magnetic resonance imaging (STEMI-SCAR project). Methods and Results ST -segment-elevation MI patients with single-vessel disease, complete occlusion with TIMI (Thrombolysis in Myocardial Infarction) score 0, absence of collateral flow (Rentrop score 0), and symptom onset <12 hours were consecutively enrolled. Using late gadolinium enhancement cardiac magnetic resonance imaging, the area at risk and infarct size, myocardial salvage index, transmurality index, and transmurality grade (0-50%, 51-75%, 76-100%) were determined. In total, 164 patients (aged 54±11 years, 80% male) were included. A receiver operating characteristic curve (area under the curve: 0.81) indicating transmural necrosis revealed the best diagnostic cutoff for a symptom-to-balloon time of 121 minutes: patients with >121 minutes demonstrated increased infarct size, transmurality index, and transmurality grade (all P<0.01) and decreased myocardial salvage index ( P<0.001) versus patients with symptom-to-balloon times ≤121 minutes. Conclusions In MI with no residual antegrade and no collateral flow, immediate reperfusion is vital. A symptom-to-balloon time of >121 minutes causes a high grade of transmural necrosis. In this pure ST -segment-elevation MI population, time to reperfusion to salvage myocardium was less than suggested by current guidelines.

Plasma LDL-Cholesterol Level at Admission is Independently Associated with Infarct Size in Patients with ST-Segment Elevation Myocardial Infarction Treated with Primary Percutaneous Coronary Intervention

Introduction

Hypercholesterolemia is a well-known risk factor for developing atherosclerosis and subsequently for the risk of a myocardial infarction (MI). Moreover, it might also be related to the extent of damaged myocardium in the event of a MI. The aim of this study was to evaluate the association of baseline low density lipoprotein-cholesterol (LDL-c) level with infarct size in patients with ST-segment elevation myocardial infarction (STEMI) after primary percutaneously coronary intervention (pPCI).

Methods

Baseline blood samples were obtained from all patients admitted between 2004 and 2014 with STEMI who underwent pPCI. Patients were excluded in case of out of hospital cardiac arrest, treatment delay of at least 10 h or no complete reperfusion after pPCI in the culprit vessel. Peak creatine kinase (CK) level was used for infarct size estimation, defined as the maximal value during admission.

Results

A total of 2248 patients were included in this study (mean age 61.8 ± 12.2 years; 25.0% female). Mean LDL-c level was 3.6 ± 1.1 mmol/L and median peak CK level was 1275 U/L (IQR 564–2590 U/L). Baseline LDL-c level [β = 0.041; (95% CI 0.019–0.062); p < 0.001] was independently associated with peak CK level. Furthermore, left anterior descending artery as culprit vessel, initial TIMI 0–1 flow in the culprit vessel, male gender, and treatment delay were also correlated with high peak CK level (p < 0.05). Prior aspirin therapy was associated with lower peak CK level [β = − 0.073 (95% CI − 0.146 to 0.000), p = 0.050].

Conclusion

This study demonstrates that besides the more established predictors of infarct size, elevated LDL-c is associated with augmented infarct size in patients with STEMI treated with pPCI.

Electronic supplementary material

The online version of this article (10.1007/s40119-019-0126-5) contains supplementary material, which is available to authorized users.

Predictors of Left Ventricular Remodeling After Myocardial Infarction in Patients With a Patent Infarct Related Coronary Artery After Percutaneous Coronary Intervention (from the Post-Myocardial Infarction Remodeling Prevention Therapy [PRomPT] Trial)

Left ventricular (LV) remodeling after myocardial infarction (MI) is a strong predictor of heart failure and mortality. The predictors of long-term remodeling after MI have been incompletely studied. We therefore examined the correlates of LV remodeling in patients with large ST-segment elevation myocardial infarction and a patent infarct artery after percutaneous 2coronary intervention (PCI) from the randomized Post-Myocardial Infarction Remodeling Prevention Therapy trial. Peri-infarct pacing had a neutral effect on long-term remodeling in patients with large first MI. The present analysis includes 109 patients in whom an open artery was restored after PCI, and in whom LV end-diastolic volume (LVEDV) at baseline and 18 months was assessed by transthoracic echocardiography. Multivariable models were fit to identify the independent predictors of LVEDV at baseline and 18 months. By multivariable analysis, male sex (p = 0.004) and anterior MI location (p = 0.03) were independently associated with baseline LVEDV. The following variables were independent predictors of increased LVEDV at 18 months: younger age (p = 0.01), male sex (p = 0.03), peak creatine phosphokinase (p = 0.03), shorter time from MI to baseline transthoracic echocardiography (p = 0.04), baseline LVEDV (p < 0.0001), and lack of statin use (p = 0.03). In conclusion, patients with large MI and an open infarct artery after PCI, anterior MI location, and male sex were associated with greater baseline LVEDV, but MI location was not associated with 18-month LVEDV. In contrast, younger age, peak creatine phosphokinase, male sex, baseline LVEDV, and lack of statin use were associated with long-term LV remodeling.

Impact of Chronic Antiplatelet Therapy on Infarct Size and Bleeding in Patients With Acute Myocardial Infarction

BACKGROUND

Patients hospitalized with acute myocardial infarction (AMI) are often on prior single antiplatelet therapy (SAPT) or a dual antiplatelet therapy (DAPT). Whether chronic SAPT or DAPT is beneficial or associated with an increased risk in AMI is still controversial.

METHODS AND RESULTS

We prospectively enrolled 1718 consecutive patients with AMI (798 ST-segment elevation myocardial infarction and 920 non-ST-segment elevation myocardial infarction) who were divided according to their chronic APT (no APT, SAPT, or DAPT). The study primary end point was the infarct size, as estimated by troponin I peak. Incidence of major bleeding was also evaluated. Five hundred thirty-six (31%) patients were on chronic SAPT and 215 (13%) on DAPT. A graded increase in Global Registry of Acute Coronary Events (GRACE) and Can Rapid risk stratification of Unstable angina patients Suppress ADverse outcomes with Early implementation of the ACC/AHA guidelines (CRUSADE) risk scores was found going from patients without APT to those with DAPT, while a progressive smaller troponin I peak was observed with the increasing number of chronic antiplatelet agents (11.2 [interquartile range: 2-45] ng/mL, 6.6 [1-33] ng/mL, and 4.1 [1-24] ng/mL; P < .001 for trend). This result was maintained after adjustment for baseline ischemic risk profile (GRACE score) and other major confounders ( P < .001). The incidence of bleeding was higher in patients on chronic APT than in those without APT (5.2% vs 2.4%; P = .002). However, when the bleeding risk was adjusted for the CRUSADE risk score, chronic SAPT (odds ratio [OR]: 1.40, 95% confidence interval [CI]: 0.77-2.53) and DAPT (OR: 0.70, 95% CI: 0.29-1.70) were not associated with an increased bleeding risk.

CONCLUSION

In patients with AMI, chronic APT is associated with higher baseline ischemic and bleeding risks. Despite this and unexpectedly, they have a smaller infarct size and similar adjusted bleeding risk.

Infarct size, left ventricular function, and prognosis in women compared to men after primary percutaneous coronary intervention in ST-segment elevation myocardial infarction: results from an individual patient-level pooled analysis of 10 randomized trials

Aim

Studies have reported less favourable outcomes in women compared with men after primary percutaneous coronary intervention (PCI) in ST-segment elevation myocardial infarction (STEMI). Whether sex-specific differences in the magnitude or prognostic impact of infarct size or post-infarction cardiac function explain this finding is unknown.

Methods and results

We pooled patient-level data from 10 randomized primary PCI trials in which infarct size was measured within 1 month (median 4 days) by either cardiac magnetic resonance imaging or technetium-99m sestamibi single-photon emission computed tomography. We assessed the association between sex, infarct size, and left ventricular ejection fraction (LVEF) and the composite rate of death or heart failure (HF) hospitalization within 1 year. Of 2632 patients with STEMI undergoing primary PCI, 587 (22.3%) were women. Women were older than men and had a longer delay between symptom onset and reperfusion. Infarct size did not significantly differ between women and men, and women had higher LVEF. Nonetheless, women had a higher 1-year rate of death or HF hospitalization compared to men, and while infarct size was a strong independent predictor of 1-year death or HF hospitalization (P < 0.0001), no interaction was present between sex and infarct size or LVEF on the risk of death or HF hospitalization.

Conclusions

In this large-scale, individual patient-level pooled analysis of patients with STEMI undergoing primary PCI, women had a higher 1-year rate of death or HF hospitalization compared to men, a finding not explained by sex-specific differences in the magnitude or prognostic impact of infarct size or by differences in post-infarction cardiac function.

Call-to-balloon time dashboard in patients with ST-segment elevation myocardial infarction results in significant improvement in the logistic chain

AIMS

Timely reperfusion with primary percutaneous coronary intervention (pPCI) in ST-segment elevation myocardial infarction (STEMI) patients is associated with superior clinical outcomes. Aiming to reduce ischaemic time, an innovative system for home-to-hospital (H2H) time monitoring was implemented, which enabled real-time evaluation of ischaemic time intervals, regular feedback and improvements in the logistic chain. The objective of this study was to assess the results after implementation of the H2H dashboard for monitoring and evaluation of ischaemic time in STEMI patients.

METHODS AND RESULTS

Ischaemic time in STEMI patients transported by emergency medical services (EMS) and treated with pPCI in the Noordwest Ziekenhuis, Alkmaar before (2008-2009; n=495) and after the implementation of the H2H dashboard (2011-2014; n=441) was compared. Median time intervals were significantly shorter in the H2H group (door-to-balloon time 32 [IQR 25-43] vs. 40 [IQR 28-55] minutes, p-value <0.001, FMC-to-balloon time 62 [IQR 52-75] vs. 80 [IQR 67-103] minutes, p-value <0.001, and treatment delay 142 [IQR 103-221] vs. 159 [IQR 123-253] minutes, p-value <0.001). The H2H time dashboard was independently associated with shorter time delays.

CONCLUSIONS

Real-time monitoring and feedback on time delay with the H2H dashboard improves the logistic chain in STEMI patients, resulting in shorter ischaemic time intervals.

Heart failure after myocardial infarction in the era of primary percutaneous coronary intervention: Mechanisms, incidence and identification of patients at risk

Myocardial infarction (MI) remains the most common cause of heart failure (HF) worldwide. For almost 50 years HF has been recognised as a determinant of adverse prognosis after MI, but efforts to promote myocardial repair have failed to translate into clinical therapies. Primary percutaneous coronary intervention (PPCI) has driven improved early survival after MI, but its impact on the incidence of downstream HF is debated. The effects of PPCI are confounded by the changing epidemiology of MI and HF, with an ageing patient demographic, an increasing proportion of non-ST-elevation myocardial infarction, and the recognition of HF with preserved ejection fraction. Herein we review the mechanisms of HF after MI and discuss contemporary data on its incidence and outcomes. We review current and emerging strategies for early detection of patients at risk of HF after MI, with a view to identification of patient cohorts for novel therapeutic agents.

Mitochondrial PKC-ε deficiency promotes I/R-mediated myocardial injury via GSK3β-dependent mitochondrial permeability transition pore opening

Mitochondrial fission is critically involved in cardiomyocyte apoptosis, which has been considered as one of the leading causes of ischaemia/reperfusion (I/R)‐induced myocardial injury. In our previous works, we demonstrate that aldehyde dehydrogenase‐2 (ALDH2) deficiency aggravates cardiomyocyte apoptosis and cardiac dysfunction. The aim of this study was to elucidate whether ALDH2 deficiency promotes mitochondrial injury and cardiomyocyte death in response to I/R stress and the underlying mechanism. I/R injury was induced by aortic cross‐clamping for 45 min. followed by unclamping for 24 hrs in ALDH2 knockout (ALDH2^−/−) and wild‐type (WT) mice. Then myocardial infarct size, cell apoptosis and cardiac function were examined. The protein kinase C (PKC) isoform expressions and their mitochondrial translocation, the activity of dynamin‐related protein 1 (Drp1), caspase9 and caspase3 were determined by Western blot. The effects of N‐acetylcysteine (NAC) or PKC‐δ shRNA treatment on glycogen synthase kinase‐3β (GSK‐3β) activity and mitochondrial permeability transition pore (mPTP) opening were also detected. The results showed that ALDH2^−/− mice exhibited increased myocardial infarct size and cardiomyocyte apoptosis, enhanced levels of cleaved caspase9, caspase3 and phosphorylated Drp1. Mitochondrial PKC‐ε translocation was lower in ALDH2^−/− mice than in WT mice, and PKC‐δ was the opposite. Further data showed that mitochondrial PKC isoform ratio was regulated by cellular reactive oxygen species (ROS) level, which could be reversed by NAC pre‐treatment under I/R injury. In addition, PKC‐ε inhibition caused activation of caspase9, caspase3 and Drp1Ser⁶¹⁶ in response to I/R stress. Importantly, expression of phosphorylated GSK‐3β (inactive form) was lower in ALDH2^−/− mice than in WT mice, and both were increased by NAC pre‐treatment. I/R‐induced mitochondrial translocation of GSK‐3β was inhibited by PKC‐δ shRNA or NAC pre‐treatment. In addition, mitochondrial membrane potential (∆Ψ_m) was reduced in ALDH2^−/− mice after I/R, which was partly reversed by the GSK‐3β inhibitor (SB216763) or PKC‐δ shRNA. Collectively, our data provide the evidence that abnormal PKC‐ε/PKC‐δ ratio promotes the activation of Drp1 signalling, caspase cascades and GSK‐3β‐dependent mPTP opening, which results in mitochondrial injury‐triggered cardiomyocyte apoptosis and myocardial dysfuction in ALDH2^−/− mice following I/R stress.

Pre-hospital alarm activation for STEMI patients undergoing primary percutaneous coronary intervention in the era of transradial procedures

BACKGROUND

Transradial access (TRA) improves outcome compared with trans-femoral access for the management of patients with acute coronary syndromes. In this setting, it is unknown whether the activation of a pre-hospital alarm system (PHAS) confers additional benefit for the prognosis of patients with ST-segment elevation myocardial infarction (STEMI).

MATERIALS AND METHODS

We retrospectively analyzed a cohort of patients with a first STEMI who underwent a primary percutaneous coronary intervention (PPCI) at a single center within a prospective cohort of acute coronary syndrome patients (SPUM-ACS). TRA was used in 85% of patients. We assessed how PHAS (n=165) vs. no-PHAS (n=166) activation was associated with the composite outcome of all-cause mortality and recurrence of myocardial infarction (MI) at 1-year follow-up. As secondary outcomes, the individual clinical endpoints were separately assessed for association.

RESULTS

Compared with no-PHAS patients, patients in the PHAS group were predominantly women, and presented more frequently with dyslipidemia and cardiac arrest. A significant reduction in the composite outcome of all-cause mortality and recurrent MI at 1-year was observed in the PHAS group, compared with no-PHAS (3.6% vs. 8.5%, p=0.027). When adjusted for age, sex and resuscitation status, PHAS activation remained associated with decreased all-cause mortality and recurrent MI (HR: 0.36 [95% CI: 0.13-0.95]; p=0.040).

CONCLUSIONS

This study suggests that the benefit of PHAS activation in STEMI patients undergoing PPCI persists also in the era of TRA.

Novel cardioprotective and regenerative therapies in acute myocardial infarction: a review of recent and ongoing clinical trials

Following the original large-scale randomized trials of aspirin and β-blockade, there have been a number of major advances in pharmacological and mechanical treatments for acute myocardial infarction. Despite this progress, myocardial infarction remains a major global cause of mortality and morbidity, driving a quest for novel treatments in this area. As the understanding of mitochondrial dynamics and the pathophysiology of reperfusion injury has evolved, the last three decades have seen advances in ischemic conditioning, pharmacological and metabolic cardioprotection, as well as biological and stem-cell therapies. The aim of this review is to provide a synopsis of adjunctive cardioprotective and regenerative therapies currently undergoing or entering early clinical trials in the treatment of patients with acute myocardial infarction.

Relationship Between Infarct Size and Outcomes Following Primary PCI: Patient-Level Analysis From 10 Randomized Trials

BACKGROUND

Prompt reperfusion in patients with ST-segment elevation myocardial infarction (STEMI) reduces infarct size and improves survival. However, the intuitive link between infarct size and prognosis has not been convincingly demonstrated in the contemporary era.

OBJECTIVES

This study sought to determine the strength of the relationship between infarct size assessed early after primary percutaneous coronary intervention (PCI) in STEMI and subsequent all-cause mortality, reinfarction, and hospitalization for heart failure.

METHODS

We performed a pooled patient-level analysis from 10 randomized primary PCI trials (total 2,632 patients) in which infarct size was assessed within 1 month after randomization by either cardiac magnetic resonance (CMR) imaging or technetium-99m sestamibi single-photon emission computed tomography (SPECT), with clinical follow-up for ≥ 6 months.

RESULTS

Infarct size was assessed by CMR in 1,889 patients (71.8%) and by SPECT in 743 patients (28.2%). Median (25th, 75th percentile) time to infarct size measurement was 4 days (3, 10 days) after STEMI. Median infarct size (% left ventricular myocardial mass) was 17.9% (8.0%, 29.8%), and median duration of clinical follow-up was 352 days (185, 371 days). The Kaplan-Meier estimated 1-year rates of all-cause mortality, reinfarction, and HF hospitalization were 2.2%, 2.5%, and 2.6%, respectively. A strong graded response was present between infarct size (per 5% increase) and subsequent mortality (Cox-adjusted hazard ratio: 1.19 [95% confidence interval: 1.18 to 1.20]; p < 0.0001) and hospitalization for heart failure (adjusted hazard ratio: 1.20 [95% confidence interval: 1.19 to 1.21]; p < 0.0001), independent of age, sex, diabetes, hypertension, hyperlipidemia, current smoking, left anterior descending versus non-left anterior descending infarct vessel, symptom-to-first device time, and baseline TIMI (Thrombolysis In Myocardial Infarction) flow 0/1 versus 2/3. Infarct size was not significantly related to subsequent reinfarction.

CONCLUSIONS

Infarct size, measured by CMR or technetium-99m sestamibi SPECT within 1 month after primary PCI, is strongly associated with all-cause mortality and hospitalization for HF within 1 year. Infarct size may, therefore, be useful as an endpoint in clinical trials and as an important prognostic measure when caring for patients with STEMI.

D-Dimer Levels Predict Myocardial Injury in ST-Segment Elevation Myocardial Infarction: A Cardiac Magnetic Resonance Imaging Study

Objectives

Elevated D-dimer levels on admission predict prognosis in patients undergoing primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI), but the association of D-dimer levels with structural markers of myocardial injury in these patients is unknown.

Methods

We performed cardiac magnetic resonance (CMR) imaging in 208 patients treated with primary PCI for STEMI. CMR was performed a median of 3 days after the index procedure. Of the 208 patients studied, 75 patients had D-dimer levels above the normal range on admission (>0.5 μg/mL; high D-dimer group) while 133 had normal levels (≤0.5 μg/mL; low D-dimer group). The primary outcome was myocardial infarct size assessed by CMR. Secondary outcomes included area at risk (AAR), microvascular obstruction (MVO) area, and myocardial salvage index (MSI).

Results

In CMR analysis, myocardial infarct size was larger in the high D-dimer group than in the low D-dimer group (22.3% [16.2–30.5] versus 18.8% [10.7–26.7]; p = 0.02). Compared to the low D-dimer group, the high D-dimer group also had a larger AAR (38.1% [31.7–46.9] versus 35.8% [24.2–45.3]; p = 0.04) and a smaller MSI (37.7 [28.2–46.9] versus 47.1 [33.2–57.0]; p = 0.01). In multivariate analysis, high D-dimer levels were significantly associated with larger myocardial infarct (OR 2.59; 95% CI 1.37–4.87; p<0.01) and lower MSI (OR 2.62; 95% CI 1.44–4.78; p<0.01).

Conclusions

In STEMI patients undergoing primary PCI, high D-dimer levels on admission were associated with a larger myocardial infarct size, a greater extent of AAR, and lower MSI, as assessed by CMR data. Elevated initial D-dimer level may be a marker of advanced myocardial injury in patients treated with primary PCI for STEMI.

Association between epicardial adipose tissue volume and myocardial salvage in patients with a first ST-segment elevation myocardial infarction: An epicardial adipose tissue paradox

BACKGROUND

Epicardial adipose tissue (EAT), defined as the adipose tissue between the visceral pericardium and the outer margin of the myocardium, is associated with coronary artery disease in the general population. However, the clinical implications of EAT in patients with ST-segment elevation myocardial infarction (STEMI) remain unclear.

METHODS

A total of 142 patients with a first STEMI, who received reperfusion therapy within 12h from symptom onset, were enrolled. All patients underwent cardiac magnetic resonance imaging to evaluate infarct core (Core), area at risk (AAR), and EAT volume. Myocardial salvage index (MSI) was defined as AAR minus Core divided by AAR. Patients in the lower tertile of EAT volume were classified as the low EAT group (group L) and the other two-thirds as the high EAT group (group H).

RESULTS

The mean MSI was lower in group L than in group H (0.43±0.13 vs 0.49±0.13, p=0.01), and the mean extent of Core was higher in group L than in group H (25±10% vs 19±10%, p<0.01). Multivariate linear regression analysis including coronary risk factors and previously reported predictors of infarct size demonstrated that EAT volume was an independent predictor of MSI (β coefficient=0.002 per 1mL, p=0.002).

CONCLUSIONS

A lower EAT volume is associated with less myocardial salvage and larger infarct size in patients with a first STEMI.

Short-and long-term effects of ischemic postconditioning in STEMI patients: a meta-analysis

Background

Compelling evidence from large randomized trials demonstrates the salutary effects of ischemic postconditioning on cardioprotection against ischemic/reperfusion injury. However, some studies appear negative findings.

This study was designed to assess the short-and long-term effects of postconditioning (Poc) in studies including evolving ST-elevation myocardial infarction (STEMI).

Methods

Relevant studies were identified through an electronic literature search from the PubMed, Library of Congress, Embase, Cochrane Central Register of Controlled Trials, and ISI Web of Science. Studies published up to December 2014 were eligible for inclusion. Patients older than 18 years presenting within 12 h of the first STEMI and eligible for angioplasty were considered for the study.

Results

The 25 trials allocated 1136 patients to perform locational postconditioning cycles at the onset of reperfusion and 1153 patients to usual percutaneous coronary intervention (PCI). Ischemic postconditioning demonstrated a decrease in serum cardiac enzymes creatine kinase (CK) and CK-MB (P < 0.00001 and P =0.25, respectively) in the subgroup analysis based on direct stenting. Reduction in infarct size by imaging was showed during7 days after myocardial infarction (P =0.01), but not in the longterm (P = 0.08). The wall motion score index was improved in both the short term within 7 days (P = 0.009) and the long term over 6 months after receiving Poc (P = 0.02). All included studies were limited by the high risk of performance and publication bias.

Conclusions

Ischemic postconditioning by brief interruptions of coronary blood flow at the onset of reperfusion after PCI appears to be superior to PCI alone in reducing myocardial injury and improving left ventricular function, especially in patients who have received direct stenting in PCI.

QRS distortion in pre-reperfusion electrocardiogram is a bedside predictor of large myocardium at risk and infarct size (a METOCARD-CNIC trial substudy)

BACKGROUND

QRS distortion is an electrocardiographic (ECG) sign of severe ongoing ischemia in the setting of ST-segment elevation acute myocardial infarction (STEMI). We sought to evaluate the association between the degree of QRS distortion and myocardium at risk and final infarct size, measured by cardiac magnetic resonance (CMR).

METHODS

A total of 174 patients with a first anterior STEMI reperfused by primary angioplasty were prospectively recruited. Pre-reperfusion ECG was used to divide the study population into three groups according to the absence of QRS distortion (D0) or its presence in a single lead (D1) or in 2 or more contiguous leads (D2+). Myocardium at risk and infarct size were determined by CMR one week after STEMI. Multiple regression analysis was used to study the association of QRS distortion with myocardium at risk and infarct size, with adjustment for relevant clinical and ECG variables.

RESULTS

101 patients (58%) were in group D0, 30 (17%) in group D1, and 43 (25%) in group D2+. Compared with group D0, presence of QRS distortion (groups D2+ and D1) was associated with a significantly adjusted larger extent of myocardium at risk (group D2+: absolute increase 10.4%, 95% CI 6.1-14.8%, p<0.001; group D1: absolute increase 3.3%, 95% CI 1.3-7.9%, p=0.157) and larger infarct size (group D2+: absolute increase 10.1%, 95% CI 5.5-14.7%, p<0.001; group D1: absolute increase 4.9%, 95% CI 0.08-9.8%, p=0.046).

CONCLUSIONS

Distortion in the terminal portion of the QRS complex on pre-reperfusion ECG in two or more leads is independently associated with larger myocardium at risk and infarct size in the setting of primary angioplasty-reperfused anterior STEMI. QRS distortion in only one lead is independently associated with larger infarct size in this setting. Our findings suggest that QRS distortion analysis could be included in risk-stratification of patients presenting with anterior STEMI.

Usefulness of the Left Anterior Descending Artery Wrapping Around the Left Ventricular Apex to Predict Adverse Clinical Outcomes in Patients With Anterior Wall ST-Segment Elevation Myocardial Infarction (an INFUSE-AMI Substudy)

The relation between left anterior descending coronary artery (LAD) anatomic features and clinical outcomes in patients with anterior ST-segment elevation myocardial infarction has not been fully investigated. The Intracoronary Abciximab and Aspiration Thrombectomy in Patients With Large Anterior Myocardial Infarction (INFUSE-AMI) trial randomized 452 patients with anterior ST-segment elevation myocardial infarctions who underwent mechanical revascularization to intralesional abciximab versus no abciximab and to manual thrombus aspiration versus no aspiration. The primary end point was infarct size (percentage left ventricular mass) on contrast magnetic resonance imaging at 30 days. "Wraparound LAD" was defined as an LAD reaching the apex and supplying the apical inferior aspect of the heart. Among complete data available in 338 patients, 258 (76.3%) had wraparound LADs. Global infarct size (17.4% vs 16.1%, p = 0.64) and the left ventricular ejection fraction (49.7% vs 48.7%, p = 0.98) by contrast magnetic resonance imaging at 30 days were comparable between patients with and those without wraparound LADs. Regional apical anterior infarct size was comparable (59.5% vs 55.8%, p = 0.559) between the groups; however, apical septal (61.3% vs 48.9%, p = 0.005), apical inferior (19.0% vs 3.7%, p <0.0001), and apical lateral (12.2% vs 4.8%, p = 0.0584) infarct sizes were larger in patients with wraparound LADs compared with those with nonwraparound LADs. The incidence of new-onset severe heart failure at 1 year was significantly higher in patients with compared with those without wraparound LADs (6.3% vs 0%, p = 0.02). In conclusion, in patients with anterior ST-segment elevation myocardial infarctions, as compared with the LAD not supplying the inferior aspect of the heart, a wraparound LAD was associated with a larger left ventricular apex infarct size, resulting in worse adverse events at 1 year.

Predictors of acute myocardial infarct size in STEMI patients receiving thrombolytic therapy: A delayed contrast enhanced cardiac MRI study

INTRODUCTION

Delayed contrast enhanced Cardiac MRI has been accepted as a standard tool worldwide for determination of infarcted myocardium and viability. Infarct size as determined by cardiac MRI has important therapeutic and prognostic information.

METHODS

Twenty six STEMI patients who had received thrombolytic therapy were subjected to cardiac MRI assessment at 5-7 day of admission. Base line variables of the study population were compared with the acute infarct size as determined by the Cardiac MRI.

RESULTS

The mean acute infarct size in our study population was 27.2 ± 17.4% of LV. We found through univariate analysis that final infarct size was dependent on time to thrombolysis (p = 0.04), Status of Thrombolysis (p = 0.01), smoking status (p = 0.02), location of infarct (p < 0.00001), presence of microvascular obstruction (p = 0.01) and viability status (p = 0.0004). Thus, larger acute infarct size was seen in delayed time to thrombolysis, failed status of thrombolysis, smokers, anterior location of the infarct, presence of microvascular obstruction and non viable myocardial status.

CONCLUSION

Infarct size as determined by Cardiac MRI has been shown to carry important therapeutic and prognostic information. We have tried to evaluate predictors of acute infarct on cardiac MRI in STEMI patients during their initial hospital stay. Knowing the predictors of acute infarct size can help in early intervention and provide prognostic information for future cardiac events.

The influence of system delay on 30-day and on long-term mortality in patients with anterior versus non-anterior ST-segment elevation myocardial infarction: a cohort study

Aim

To evaluate the relationship between system delay and 30-day and long-term mortality in patients with anterior versus non-anterior ST-elevation myocardial infarction (STEMI).

Methods

We conducted a prospective observational cohort study. Patients with STEMI who were transported to the Isala Hospital, Zwolle, and underwent primary percutaneous coronary intervention (pPCI) from 2005 until 2010 were included. These patients were divided into quartiles of system delay (time from first medical contact until reperfusion therapy): Q1–Q4.

Results

In total, 3041 patients were included in our study. 41% (n=1253) of the patients had an anterior myocardial infarction (MI) and 59% of the patients (n=1788) had a non-anterior MI. Only in patients with an anterior MI, prolonged system delay was associated with a higher mortality (30-day Q1: 2.6%, Q2: 3.1%, Q3: 6.8%, Q4: 7.4%, p=0.001; long-term Q1: 12.8%, Q2: 13.7%, Q3: 24.1%, Q4: 22.6%, p<0.001). After multivariable adjustment, prolonged system delay was associated with a higher 30-day and long-term mortality in patients with an anterior MI (30 day Q2: HR 1.18, 95% CI (0.46 to 3.00), Q3: HR 2.45, 95% CI (1.07 to 5.63), Q4: HR 2.25, 95% CI (0.97 to 5.25)); long-term Q2: HR 1.09, 95% CI (0.71 to 1.68), Q3: HR 1.68, 95% CI (1.13 to 2.49), Q4: HR 1.55, 95% CI (1.03 to 2.33)), but not in patients with a non-anterior MI.

Conclusions

Prolonged system delay significantly increased short-term as well as long-term mortality in patients with an anterior MI. This effect was not demonstrated in patients with a non-anterior MI. Therefore, it is of the greatest importance to minimise system delay in patients who present with an anterior MI.

Impact of delay to reperfusion on reperfusion success, infarct size, and clinical outcomes in patients with ST-segment elevation myocardial infarction: the INFUSE-AMI Trial (INFUSE-Anterior Myocardial Infarction)

OBJECTIVES

Our aim was to study the impact of delay from symptom onset to first coronary device on infarct size and clinical outcomes at 30 days and 1 year in patients with ST-segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention.

BACKGROUND

Longer delay from symptom onset to reperfusion has been linked to increased mortality and worse clinical outcome. The mechanisms underpinning this association are not entirely clear.

METHODS

The INFUSE-AMI trial (INFUSE-Anterior Myocardial Infarction) randomized patients with anterior STEMI undergoing primary percutaneous coronary intervention with bivalirudin anticoagulation within 5 h of symptom onset to intralesion (IL) bolus abciximab versus no abciximab and to thrombus aspiration versus no aspiration. The primary endpoint was contrast magnetic resonance infarct size (IS) (percentage of left ventricular mass) at 30 days. Time to reperfusion was classified as <3 versus ≥3 h.

RESULTS

There were 280 patients (62%) with <3-h delay and 170 patients (38%) with ≥3-h delay. Patients with longer delay were significantly older, more often women, and diabetic. Earlier reperfusion was not associated with higher rates of final Thrombolysis In Myocardial Infarction flow grade 3 or myocardial blush grade 2/3, but was an independent predictor of smaller IS (p = 0.02 by multivariable linear regression). Mortality at 1 year was reduced in patients with shorter delay to reperfusion (4.0% vs. 9.2%, p = 0.02).

CONCLUSIONS

In patients with large anterior myocardial infarction undergoing relatively early reperfusion, longer delays to reperfusion were associated with larger IS and 1-year mortality, but not with reduced reperfusion success. (The INFUSE - Anterior Myocardial Infarction [AMI] Study; NCT00976521).

Impact of time from symptom onset to drug administration on outcome in patients undergoing glycoprotein IIb-IIIa facilitated primary angioplasty (from the EGYPT cooperation)

Contrasting data have been so far reported on facilitation with glycoprotein IIb-IIIa inhibitors (GpIIbIIIa) in patients who underwent primary percutaneous coronary intervention. However, it has been demonstrated a time-dependent composition of coronary thrombus in ST-segment elevation myocardial infarction, with more platelets in the first hours. Subsequently, the benefits of early administration of GpIIbIIIa may be affected by the time from symptoms onset to GpIIbIIIa, that therefore is the aim of this study. Our population is represented by 814 patients who underwent GpIIbIIIa facilitated primary angioplasty included in the Early glycoprotein IIb-IIIa inhibitors in primary angioplasty database. Patients were divided according to quartiles of time from symptom onset to GpIIbIIIa administration (≤65 minutes; 65 to 100 minutes; 101 to 178 minutes; and >178 minutes). Myocardial perfusion was evaluated by myocardial blush grade and ST-segment resolution. Time from symptoms onset to GpIIbIIIa was linearly associated with hypertension, diabetes, hypercholesterolemia, and previous myocardial infarction but inversely associated with smoking. Abciximab was more often administrated later from symptoms onset. Time from symptoms onset to GpIIbIIIa was significantly associated with the rate of preprocedural recanalization (thrombolysis in myocardial infarction [TIMI] 2 to 3; p <0.001), postprocedural TIMI 3 flow (p <0.001), the rate of complete ST-segment resolution (p <0.001), and the rate of myocardial blush grade 2 to 3 (p <0.001) and inversely associated with the occurrence of distal embolization (p <0.001). Follow-up data were collected at a median (twenty-fifth to seventy-fifth) of 360 (30 to 1,095) days. A total of 52 patients had died. Time to GpIIbIIIa had a significant impact on mortality (hazard ratio [95% confidence interval] 1.46 [1.11 to 1.92], p = 0.007) that was confirmed after correction for baseline confounding factors (adjusted hazard ratio [95% confidence interval] 1.41 [1.02 to 2.21], p = 0.042). In conclusion, this study showed that in patients who underwent primary angioplasty with upstream GpIIbIIIa, time from symptoms onset to GpIIbIIIa strongly impacts on preprocedural recanalization, distal embolization, myocardial perfusion, and long-term survival.

Sex, adverse cardiac events, and infarct size in anterior myocardial infarction: an analysis of intracoronary abciximab and aspiration thrombectomy in patients with large anterior myocardial infarction (INFUSE-AMI)

BACKGROUND

Women are more likely than men to experience adverse cardiac events after ST-elevation myocardial (STEMI). Whether differences in infarct size or reperfusion contribute to sex differences in outcomes is unknown.

METHODS

We compared baseline and procedural characteristics, angiographic and electrocardiographic indices of reperfusion, microvascular obstruction, infarct size, and clinical outcomes in 118 women and 334 men with anterior STEMI enrolled in the INFUSE-AMI randomized trial of intralesion abciximab and aspiration thrombectomy (NCT00976521). Infarct size was assessed by cardiac magnetic resonance imaging at 30 days, and clinical end points were adjudicated by an independent committee.

RESULTS

Women were older, were more commonly affected by hypertension and renal impairment, and had a 50.5-minute longer delay to reperfusion. There were no differences in infarct size, microvascular obstruction, or reperfusion success. At 30 days, major adverse cardiac events (MACE), defined as death, reinfarction, new-onset severe heart failure, or rehospitalization for heart failure, were more common in women (11.1% vs 5.4%, hazard ratio 2.09, 95% CI 1.03-4.27, P = .04). After multivariable adjustment, age, but not sex or time to reperfusion, was an independent predictor of MACE.

CONCLUSIONS

In the INFUSE-AMI randomized trial, women with anterior STEMI experienced a higher rate of MACE, attributable to older age. Despite longer delay from symptom onset to reperfusion therapy, there was no difference between women and men in infarct size or reperfusion success.