Benefit From Reperfusion With Primary Percutaneous Coronary Intervention Beyond 12 Hours of Symptom Duration in Patients With ST-Segment–Elevation Myocardial Infarction

Characteristics, management and outcome of patients with late-arrival STEMI in the Acute Coronary Syndrome Israeli Surveys (ACSIS)

Introduction

Patients with ST-elevation myocardial infarction (STEMI) and late arrival (>12 h) after symptom onset, are at high risk for mortality and heart failure and represent a challenge for management. We aimed to define patient characteristics, management, and outcome of late-arrival STEMI in Israel over the last 20 years.

Methods

We analyzed data of late-arrival STEMI (12-48 h and > 48 h) from the biennial acute coronary syndrome Israeli Surveys (ACSIS), as well as time-dependent changes [early (2000-2010) Vs. late (2013-2021) period].

Results

Data regarding time from symptom onset to hospital arrival was available in 6,466 STEMI patients. Of these, 9.6 % arrived 12-48 h and 3 % >48 h from symptom onset. Late-arrival patients were more likely to be older women with diabetes and high GRACE score and less likely to have prior myocardial infarction.In recent years, 95 % of patients arriving 12-48 h and 96 % of those arriving > 48 h had coronary angiography, as opposed to 75 % and 77 % in the early years (p = 0.007). Percutaneous coronary intervention (PCI) increased from 60 % and 55 % respectively to 85 % (p ≤ 0.001).TIMI-3 flow after primary PCI was 89-92 %, irrespective of arrival time. Late arrival patients (12-48 h but not > 48 h) who had PCI had better adjusted 1-year survival, HR 0.49 (95 %CI 0.29-0.82), p = 0.01.

Conclusions

Late-arrival STEMI patients have higher risk characteristics. Most late-arrival patients undergo coronary angiography and PCI and have TIMI-3 flow after primary PCI. In patients arriving 12-48 h after symptom onset PCI is associated with better survival.

Prognostic Value of Follow-up Measures of Left Ventricular Global Longitudinal Strain in Patients With ST-Segment Elevation Myocardial Infarction

INTRODUCTION

After ST-segment elevation myocardial infarction (STEMI), follow-up imaging is currently recommended only in patients with left ventricular ejection fraction (LVEF) <40%. Left ventricular global longitudinal strain (LVGLS) was shown to improve risk stratification over LVEF in these patients but has not been thoroughly studied during follow-up. The aim of this study was to explore the changes in LVGLS after STEMI and their potential prognostic value.

MATERIALS AND METHODS

Data were analyzed from an ongoing STEMI registry. Echocardiography was performed during the index hospitalization and 1 year after STEMI; LVGLS was expressed as an absolute value and the relative LVGLS change (ΔGLS) was calculated. The study end point was all-cause mortality.

RESULTS

A total of 1,409 STEMI patients (age 60 ± 11 years; 75% men) who survived at least 1 year after STEMI and underwent echocardiography at follow-up were included. At 1-year follow-up, LVEF improved from 50% ± 8% to 53% ± 8% (P < .001) and LVGLS from 14% ± 4% to 16% ± 3% (P < .001). Median ΔGLS was 14% (interquartile range, 0.5%-32%) relative improvement. Starting 1 year after STEMI, a total of 87 patients died after a median follow-up of 69 (interquartile range, 38-103) months. The optimal ΔGLS threshold associated with the end point (derived by spline curve analysis) was a relative decrease >7%. Cumulative 10-year survival was 91% in patients with ΔGLS improvement or a nonsignificant decrease, versus 85% in patients with ΔGLS decrease of >7% (P = .001). On multivariate Cox regression analysis, ΔGLS decrease >7% remained independently associated with the end point (hazard ratio, 2.5 [95% CI, 1.5-4.1]; P < .001) after adjustment for clinical and echocardiographic parameters.

CONCLUSIONS

A significant decrease in LVGLS 1 year after STEMI was independently associated with long-term all-cause mortality and might help further risk stratification and management of these patients during follow-up.

Treatment and Care of Patients with ST-Segment Elevation Myocardial Infarction-What Challenges Remain after Three Decades of Primary Percutaneous Coronary Intervention?

Primary percutaneous coronary intervention (pPCI) has revolutionized the prognosis of ST-segment elevation myocardial infarction (STEMI) and is the gold standard treatment. As a result of its success, the number of pPCI centres has expanded worldwide. Despite decades of advancements, clinical outcomes in STEMI patients have plateaued. Out-of-hospital cardiac arrest and cardiogenic shock remain a major cause of high in-hospital mortality, whilst the growing burden of heart failure in long-term STEMI survivors presents a growing problem. Many elements aiming to optimize STEMI treatment are still subject to debate or lack sufficient evidence. This review provides an overview of the most contentious current issues in pPCI in STEMI patients, with an emphasis on unresolved questions and persistent challenges.

Imaging Predictors of Left Ventricular Functional Recovery after Reperfusion Therapy of ST-Elevation Myocardial Infarction Assessed by Cardiac Magnetic Resonance

BACKGROUND

Left ventricular global longitudinal strain (LV GLS) is a superior predictor of adverse cardiac events in patients with myocardial infarction and heart failure. We investigated the ability of morphological features of infarcted myocardium to detect acute left ventricular (LV) dysfunction and predict LV functional recovery after three months in patients with acute ST-segment elevation myocardial infarction (STEMI).

METHODS

Sixty-six STEMI patients were included in the C-reactive protein (CRP) apheresis in Acute Myocardial Infarction Study (CAMI-1). LV ejection fraction (LVEF), LV GLS, LV global circumferential strain (LV GCS), infarct size (IS), area-at-risk (AAR), and myocardial salvage index (MSI) were assessed by CMR 5 ± 3 days (baseline) and 12 ± 2 weeks after (follow-up) the diagnosis of first acute STEMI.

RESULTS

Significant changes in myocardial injury parameters were identified after 12 weeks of STEMI diagnosis. IS decreased from 23.59 ± 11.69% at baseline to 18.29 ± 8.32% at follow-up (p < 0.001). AAR and MVO also significantly reduced after 12 weeks. At baseline, there were reasonably moderate correlations between IS and LVEF (r = -0.479, p < 0.001), LV GLS (r = 0.441, p < 0.001) and LV GCS (r = 0.396, p = 0.001) as well as between AAR and LVEF (r = -0.430, p = 0.003), LV GLS (r = 0.501, p < 0.001) and weak with LV GCS (r = 0.342, p = 0.020). At follow-up, only MSI and change in LV GCS over time showed a weak but significant correlation (r = -0.347, p = 0.021). Patients with larger AAR at baseline improved more in LVEF (p = 0.019) and LV GLS (p = 0.020) but not in LV GCS.

CONCLUSION

The CMR tissue characteristics of myocardial injury correlate with the magnitude of LV dysfunction during the acute stage of STEMI. AAR predicts improvement in LVEF and LV GLS, while MSI is a sensitive marker of LV GCS recovery at three months follow-up after STEMI.

Treatment strategies of acute myocardial infarction: updates on revascularization, pharmacological therapy, and beyond

Owing to recent advances in early reperfusion strategies, pharmacological therapy, standardized care, and the identification of vulnerable patient subsets, the prognosis of acute myocardial infarction has improved. However, there is still considerable room for improvement. This review article summarizes the latest evidence concerning clinical diagnosis and treatment of acute myocardial infarction.

Late Presenters with ST-Elevation Myocardial Infarction: A Call to Action

The emphasis on timely coronary reperfusion in the setting of ST-segment elevation Myocardial Infarction (STEMI) comes from older studies suggesting a significant reduction in mortality among patients treated with fibrinolytic therapy during the first hours after onset of symptoms and a progressive increase in fatal events in those presenting later [...]

Prognostic value of myocardial salvage index assessed by cardiovascular magnetic resonance in reperfused ST-segment elevation myocardial infarction

Aims

Cardiovascular magnetic resonance (CMR) is a powerful tool to quantify the myocardial area at risk (AAR) and infarct size (IS), and evaluate the extent of myocardial salvage in acute ST-segment elevation myocardial infarction (STEMI). This study aimed to assess the prognostic value of myocardial salvage index (MSI) assessed by CMR in reperfused STEMI and investigate whether MSI could improve the predictive efficacy of the Global Registry of Acute Coronary Events (GRACE) risk score.

Methods and results:

About 104 consecutive patients who were hospitalized with first-time STEMI and received reperfusion therapy were prospectively enrolled. The primary endpoint was the incident of major adverse cardiovascular event (MACE) including all-cause mortality, non-fatal myocardial reinfarction and congestive heart failure within 36 months after the index event. Cox regression analysis was used to evaluate the prognostic association of MSI with MACE risk. About 21 (20.2%) patients developed MACE during the 3-year follow-up period, and patients with MSI &lt; median had a higher incidence of MACE than those with MSI ≥ median [16 (30.8%) vs. 5 (9.6%), P = 0.007]. After adjusting all the parameters associated with MACE in univariate Cox analysis, MSI assessed by CMR remained independently significant as a predictor of MACE in multivariate Cox analysis (hazard ratio 0.963, 95% CI: 0.943–0.983; P &lt; 0.001). Adding MSI to the GRACE risk score significantly increased the prognostic accuracy of the GRACE risk score (area under the curve: 0.833 vs. 0.773; P = 0.044), with a net reclassification improvement of 0.635 (P = 0.009) and an integrated discrimination improvement of 0.101 (P = 0.002).

Conclusion

This study confirmed that MSI assessed by CMR had a good long-term prognostic value in reperfused STEMI and improve the prognostic performance of the GRACE risk score.

Pandemic-Associated Delays in Myocardial Infarction Presentation in Predominantly Rural Counties With Low COVID-19 Prevalence

Fewer ST-elevation myocardial infarctions (STEMIs) presentations and increased delays in care occurred during the COVID-19 pandemic in urban areas. Whether these associations occurred in a more rural population has not been previously reported. Our objective was to evaluate the impact of COVID-19 on time-to-presentation for STEMI in rural locations. Patients presenting to a large STEMI network spanning 27 facilities and 13 predominantly rural counties between January 1, 2016 and April 30, 2020 were included. Presentation delays, defined as time from symptom onset to arrival at the first medical facility, classified as ≥12 and ≥24 hours from symptom onset were compared among patients in the pre–COVID-19 and the early COVID-19 eras. To account for patient-level differences, 2:1 propensity score matching was performed using binary logistic regression. Among 1,286 patients with STEMI, 1,245 patients presented in the pre–COVID-19 era and 41 presented during the early COVID-19 era. Presentation delays ≥12 hours (19.5% vs 4.0%) and ≥24 hours (14.6% and 0.2%) were more common in COVID-19 than pre–COVID-19 cohorts (p <0.001 for both), despite a low COVID-19 prevalence. Similar results were seen in propensity-matched comparisons (≥12 hours: 19.5% vs 2.4%, p = 0.002; ≥24 hours 14.6% vs 0.0%, p = 0.001). In a predominantly rural STEMI population, delays in seeking medical care after symptom onset were markedly more frequent during the COVID-19 era, despite low COVID-19 prevalence. Considering delays in reperfusion have multiple adverse downstream consequences, these findings may have important implications in rural communities during future pandemic resurgences.

Late primary angioplasty (beyond 12 h): are we sure it should be avoided?

Optimal management for patients with ST-segment elevation myocardial infarction (STEMI) who arrive at a hospital late remains uncertain since evidence and real-world data are limited. Patients who present late with a STEMI are a heterogeneous population, and the clinical decision regarding percutaneous coronary intervention (PCI) should not be the same for all. One randomized clinical trial, multiple mechanistic studies, and contemporary registries suggest a presumed benefit for a prompt restoration of coronary flow even in late presenting STEMI. Crucial elements in decision-making are the presence of haemodynamic or electrical instability, and ongoing ischaemic signs or symptoms to tip the scales toward PCI. Among clinically stable, late-presenting patients, myocardial viability assessment and functional testing can identify yet another subgroup that may benefit from late PCI

Percutaneous Myocardial Revascularization in Late-Presenting Patients With STEMI

BACKGROUND

The optimal management of patients with ST-segment elevation myocardial infarction (STEMI) presenting late->12 hours following symptom onset-is still under debate.

OBJECTIVES

The purpose of this study was to describe characteristics, temporal trends, and impact of revascularization in a large population of latecomer STEMI patients.

METHODS

The authors analyzed the data of 3 nationwide observational studies from the FAST-MI (French Registry of Acute ST-elevation and non-ST-elevation Myocardial Infarction) program, conducted over a 1-month period in 2005, 2010, and 2015. Patients presenting between 12 and 48 hours after symptom onset were classified as latecomers.

RESULTS

A total of 6,273 STEMI patients were included in the 3 cohorts, 1,169 (18.6%) of whom were latecomers. After exclusion of patients treated with fibrinolysis and patients deceased within 2 days after admission, 1,077 patients were analyzed, of whom 729 (67.7%) were revascularized within 48 hours after hospital admission. At 30-day follow-up, all-cause death rate was significantly lower among revascularized latecomers (2.1% vs 7.2%; P < 0.001). After a median follow-up of 58 months, the rate of all-cause death was 30.4 (95% CI: 25.7-35.9) per 1,000 patient-years in the revascularized latecomers group vs 78.7 (95% CI: 67.2-92.3) per 1,000 patient-years in the nonrevascularized latecomers group (P < 0.001). In multivariate analysis, revascularization of latecomer STEMI patients was independently associated with a significant reduction of mortality occurrence during follow-up (HR: 0.65 [95% CI: 0.50-0.84]; P = 0.001).

CONCLUSIONS

Coronary revascularization of latecomer STEMI patients is associated with better short and long-term clinical outcomes.

Percutaneous Intracoronary Delivery of Plasma Extracellular Vesicles Protects the Myocardium Against Ischemia-Reperfusion Injury in Canis

[Figure: see text].

Diagnosis and Management of Late-presentation ST-elevation Myocardial Infarction and Complications

The incidence of late presentation of myocardial infarction varies between 8.5% and 40%. Late revascularization of an infarct-related artery may limit infarct size and remodeling, reduce electrical instability, and may provide supplemental blood supply to that area via collaterals. Randomized clinical trials have shown a benefit of revascularization in symptomatic and hemodynamically unstable latecomers. Image stress testing can be beneficial to guide management of asymptomatic late presenters. Higher rates of myocardial infarction complications occur with late presentations, so a high level of suspicion is required for early diagnosis. Surgical repair remains the gold standard for management of mechanical complications.

Management of ST Elevation Myocardial Infarction (STEMI) in Different Settings

ST-segment elevation myocardial infarction (STEMI) is a life-threatening condition that requires emergent, complex, well-coordinated treatment. Although the primary goal of treatment is simple to describe-reperfusion as quickly as possible-the management process is complicated and is affected by multiple factors including location, patient, and practitioner characteristics. Hence, this narrative review will discuss the recommended management and treatment strategies of STEMI in the circumstances.

Stroke and Heart Attack Symptom Recognition in Older US Adults by Cognitive Impairment Status

INTRODUCTION

Cognitive impairment may make stroke and heart attack symptom recognition difficult, potentially resulting in treatment delays for those with these cardiovascular diseases (CVDs). Despite cognitive impairment affecting large numbers of older US adults who are also at increased risk of stroke and heart attack, little is known about stroke and heart attack symptom recognition in this population. As a result, this study sought to determine the impact of cognitive impairment on stroke and heart attack symptom recognition among older US adults.

METHODS

Using the 2014 and 2017 National Health Interview Surveys, we compared stroke and heart attack symptom recognition levels in US adults aged ≥65 years with cognitive impairment and those without cognitive impairment. Estimates of stroke and heart attack symptom recognition adjusted for CVD-related factors were assessed by cognitive impairment status. We also conducted analyses stratified by living arrangement and stroke and heart attack history for individuals with and without cognitive impairment.

RESULTS

US adults aged ≥65 years with cognitive impairment were observed to be 3.0-6.7% and 1.6-4.9%, respectively, less likely to recognize an individual stroke and heart attack symptom than similarly aged individuals without cognitive impairment. Recognition of all 5 stroke/heart attack symptoms was also lower among those with cognitive impairment, with this group being 9.7% less likely to recognize all stroke symptoms and 6.7% less likely to recognize all 5 heart attack symptoms compared to people without cognitive impairment. Following adjustment, individuals with cognitive impairment continued to have slightly lower recognition of certain individual stroke and heart attack symptoms as well as of all 5 symptoms of these conditions (stroke OR: 0.70 [95% CI: 0.58-0.85]; heart attack OR: 0.88 [95% CI: 0.75, 1.03]) than those without cognitive impairment. For individuals with cognitive impairment, living with others was linked with slightly better recognition of all individual stroke symptoms and heart attack history with better recognition of all individual heart attack symptoms.

CONCLUSIONS

Additional work is needed to address the challenge of improving recognition levels for specific stroke and heart attack symptoms in older US adults with cognitive impairment and especially for members of this group who live alone.

Immediate Compared With Delayed Percutaneous Coronary Intervention for Patients With ST-Segment-Elevation Myocardial Infarction Presenting ≥12 Hours After Symptom Onset Is Not Associated With Improved Clinical Outcome

[Figure: see text].

Long-Term Outcomes of Patients With Late Presentation of ST-Segment Elevation Myocardial Infarction

BACKGROUND

Real-world data on baseline characteristics, clinical practice, and outcomes of late presentation (12 to 48 h of symptom onset) in patients with ST-segment elevation myocardial infarction (STEMI) are limited.

OBJECTIVES

This study aimed to investigate real-world features of STEMI late presenters in the contemporary percutaneous coronary intervention (PCI) era.

METHODS

Of 13,707 patients from the Korea Acute Myocardial Infarction Registry-National Institutes of Health database, 5,826 consecutive patients diagnosed with STEMI within 48 h of symptom onset during 2011 to 2015 were categorized as late (12 to 48 h; n = 624) or early (<12 h; n = 5,202) presenters. Coprimary outcomes were 180-day and 3-year all-cause mortality.

RESULTS

Late presenters had remarkably worse clinical outcomes than early presenters (180-day mortality: 10.7% vs. 6.8%; 3-year mortality: 16.2% vs. 10.6%; both log-rank p < 0.001), whereas presentation at ≥12 h of symptom onset was not independently associated with increased mortality after STEMI. The use of invasive interventional procedures abruptly decreased from the first (<12 h) to the second (12 to 24 h) 12-h interval of symptom-to-door time ("no primary PCI strategy" increased from 4.9% to 12.4%, and "no PCI" from 2.3% to 6.6%; both p < 0.001). Mortality rates abruptly increased from the first to the second 12-h interval of symptom-to-door time (from 6.8% to 11.2% for 180-day mortality; from 10.6% to 17.3% for 3-year mortality; all p < 0.05).

CONCLUSIONS

Data from a nationwide prospective Korean registry reveal that inverse steep differences in the use of invasive interventional procedures and mortality rates were found between early and late presenters after STEMI. A multidisciplinary approach is required in identifying late presenters of STEMI who can benefit from invasive interventional procedures until further studied.

Outcome of inter-hospital transfer versus direct admission for primary percutaneous coronary intervention: An observational study of 25,315 patients with ST-elevation myocardial infarction from the London Heart Attack Group

Background and aims:

In patients with ST-segment elevation myocardial infarction (STEMI), mortality is directly related to time to reperfusion with guidelines recommending patients be delivered directly to centres for primary percutaneous coronary intervention (PCI). The aim of this study was to describe the impact of inter-hospital transfer on reperfusion time and to assess whether or not treatment delays influenced clinical outcomes in comparison with direct admission to a primary PCI centre in a large regional network.

Method and results:

We undertook an observational cohort study of patients with STEMI treated with primary PCI between 2005 and 2015 in London, UK. Patient details were recorded at the time of the procedure in databases using the British Cardiovascular Intervention Society PCI dataset. The primary end-point was all-cause mortality at a median of 4.1 years (interquartile range: 2.2–5.8 years). Secondary outcomes were in-hospital major adverse cardiac events. Of 25,315 patients, 17,560 (69.4%) were admitted directly to a primary PCI centre and 7755 (31.6%) were transferred from a non-primary PCI centre. Patients in the direct admission group were older and more likely to have left ventricular impairment compared with the inter-hospital transfer group. Median time from call for help to reperfusion in transferred patients was 52 minutes longer compared with patients admitted directly (p &lt;0.001). However, call to first hospital admission was similar. Kaplan–Meier analysis demonstrated significantly lower mortality rates in patients who were transferred directed to a primary PCI centre compared with patients who were transferred from a non-PCI centre (17.4% direct vs. 18.7% transfer, p=0.017). Furthermore, after propensity matching, direct admission for primary PCI was still a predictor of all-cause mortality (hazard ratio: 0.89, 95% confidence interval: 0.64–0.95).

Conclusions:

In this large registry of over 25,000 STEMI patients treated by primary PCI survival was better in patients admitted directly to a cardiac centre versus patients transferred for primary PCI, most likely due to longer call to balloon times in patient transferred from other hospitals.

Targeting myocardial ischaemic injury in the absence of reperfusion

Sudden myocardial ischaemia causes an acute coronary syndrome. In the case of ST-elevation myocardial infarction (STEMI), this is usually caused by the acute rupture of atherosclerotic plaque and obstruction of a coronary artery. Timely restoration of blood flow can reduce infarct size, but ischaemic regions of myocardium remain in up to two-thirds of patients due to microvascular obstruction (MVO). Experimentally, cardioprotective strategies can limit infarct size, but these are primarily intended to target reperfusion injury. Here, we address the question of whether it is possible to specifically prevent ischaemic injury, for example in models of chronic coronary artery occlusion. Two main types of intervention are identified: those that preserve ATP levels by reducing myocardial oxygen consumption, (e.g. hypothermia; cardiac unloading; a reduction in heart rate or contractility; or ischaemic preconditioning), and those that increase myocardial oxygen/blood supply (e.g. collateral vessel dilation). An important consideration in these studies is the method used to assess infarct size, which is not straightforward in the absence of reperfusion. After several hours, most of the ischaemic area is likely to become infarcted, unless it is supplied by pre-formed collateral vessels. Therefore, therapies that stimulate the formation of new collaterals can potentially limit injury during subsequent exposure to ischaemia. After a prolonged period of ischaemia, the heart undergoes a remodelling process. Interventions, such as those targeting inflammation, may prevent adverse remodelling. Finally, harnessing of the endogenous process of myocardial regeneration has the potential to restore cardiomyocytes lost during infarction.

Interstitial changes after reperfused myocardial infarction in swine: morphometric and genetic analysis

Background

Following myocardial infarction (MI), we aimed to characterize morphometric and genetic changes in extracellular matrix (ECM) components from ischemia onset until late phases after coronary reperfusion in necrotic and salvaged myocardium.

Results

Swine were divided into one control (n = 5) and three MI groups: 90-min of ischemia without reperfusion, or followed by 1-week or 1-month reperfusion (n = 5 per group). In samples from the necrotic and salvaged areas, ECM components were morphometrically quantified and mRNA levels of factors involved in ECM remodeling were evaluated. After 90-min of ischemia, fibronectin, laminin, and elastic fibers content as well as upregulated mRNA expression of tissue inhibitors of metalloproteinases (TIMP)1, TIMP2, TIMP3 and connective tissue growth factor increased in the necrotic and salvaged myocardium. In both reperfused MI groups, collagen-I, collagen-III, elastic fibers, glycosaminoglycans, laminin, and fibronectin levels heightened in the necrotic but not the salvaged myocardium. Moreover, mRNA expression of TIMP1, TIMP2 and TIMP3, as well as metalloproteinase-2 and metalloproteinase-9 heightened in the necrotic but not in the salvaged myocardium.

Conclusions

Matrix remodeling starts after ischemia onset in both necrotic and salvaged myocardium. Even if ECM composition from the salvaged myocardium was altered after severe ischemia, ECM makes a full recovery to normal composition after reperfusion. Therefore, rapid coronary reperfusion is essential not only to save cardiomyocytes but also to preserve matrix, thus avoiding impaired left ventricular remodeling.

Electrocardiogram to predict reperfusion success in late presenters with ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention

BACKGROUND

Clinical decision-making in patients with ST-segment elevation myocardial infarction (STEMI) presenting beyond 12 h of symptom onset (late presenters) is challenging. However, the electrocardiogram (ECG) may provide helpful information. We investigated the association between three ECG-scores and myocardial salvage and infarct size in late presenters treated with primary percutaneous coronary intervention (primary PCI).

METHODS

Sixty-six patients with STEMI and ongoing symptoms presenting 12-72 h after symptom onset were included. Cardiac magnetic resonance was performed at day 1 (interquartile range [IQR], 1-1) and at follow-up at day 93 (IQR, 90-98). The pre-PCI ECG was analyzed for the presence of pathological QW (early QW) as well as Anderson-Wilkins acuteness score (AW-score), the classic Sclarovsky-Birnbaum Ischemia Grading System (classic SB-IG-score) and a modified SB-IG-score including any T-wave morphologies.

RESULTS

Early QW was associated with a larger myocardium at risk (39 ± 12 versus 33 ± 12; p = 0.030) and final infarct size (20 ± 11 versus 14 ± 9; p = 0.021) as well as a numerical lower final myocardial salvage (0.52 ± 0.19 versus 0.61 ± 0.23; p = 0.09). The association with final infarct size disappeared after adjusting for myocardium at risk. An AW-score < 3 showed a trend towards a larger final infarct size (18 ± 11 versus 11 ± 11; p = 0.08) and was not associated with salvage index (0.55 ± 0.20 versus 0.65 ± 0.30; p = 0.23). The classic and modified SB-IG-score were not associated with final infarct size (modified SB-IG-score, 17 ± 10 versus 21 ± 13; p = 0.28) or final myocardial salvage (0.53 ± 0.20 versus 0.53 ± 0.26; p = 0.96).

CONCLUSION

Of three well-established ECG-scores only early QW and AW-score < 3 showed association with myocardium at risk and infarct size to some extent, but the association with myocardial salvage was weak. Hence, neither of the three investigated ECG-scores are sufficient to guide clinical decision-making in patients with STEMI and ongoing symptoms presenting beyond 12 h of symptom onset.

Delayed Reperfusion-Coronary Artery Reperfusion Close to Complete Myocardial Necrosis Benefits Remote Myocardium and Is Enhanced by Exercise

The present study aimed to analyze the effects of reperfusion of a distant coronary artery on cardiac function, the ultrastructure, and the molecular environment of the remote myocardium immediately after the completion of myocardial regional necrosis: delayed reperfusion (DR). Additionally, the effects of prior exercise on the outcomes of DR were investigated. Female rats with permanent occlusion or delayed reperfusion were randomly assigned to an exercise (swimming, 1 h/day, 5 days/week for 8 weeks) or sedentary protocol. Thus, the study included the following four groups: sedentary permanent occlusion, exercise permanent occlusion, sedentary delayed reperfusion, and exercise delayed reperfusion. The descending coronary artery was occluded for 1 h. Reperfusion was confirmed by contrast echocardiography, and the rats were observed for 4 weeks. Permanent occlusion and DR caused similar myocardial infarction sizes among the four groups. Interestingly, exercise significantly decreased the mortality rate. Delayed reperfusion resulted in significant benefits, including enhanced hemodynamics and papillary muscle contraction, as well as reduced apoptosis and collagen content. Protein calcium kinetics did not change. Meanwhile, developed tension and the Frank–Starling mechanism were enhanced, suggesting that calcium sensitivity was intensified in myofilaments. Remarkable remote myocardial benefits occurred after distant DR, and prior exercise intensified cardiac recovery. Our findings provide valuable information about DR. Our data might explain the better clinical outcomes in recent studies showing that late reperfusion could improve heart failure in patients with myocardial infarction. In conclusion, DR has remote myocardial benefits, including inotropism enhancement, pulmonary congestion reduction, and collagen and apoptosis attenuation, which are enhanced by prior exercise.