Role of Cardiac Magnetic Resonance to Improve Risk Prediction Following Acute ST-Elevation Myocardial Infarction

Comprehensive characterization of cardiac contraction for improved post-infarction risk assessment

This study aims at identifying risk-related patterns of left ventricular contraction dynamics via novel volume transient characterization. A multicenter cohort of AMI survivors (n = 1021) who underwent Cardiac Magnetic Resonance (CMR) after infarction was considered for the study. The clinical endpoint was the 12-month rate of major adverse cardiac events (MACE, n = 73), consisting of all-cause death, reinfarction, and new congestive heart failure. Cardiac function was characterized from CMR in 3 potential directions: by (1) volume temporal transients (i.e. contraction dynamics); (2) feature tracking strain analysis (i.e. bulk tissue peak contraction); and (3) 3D shape analysis (i.e. 3D contraction morphology). A fully automated pipeline was developed to extract conventional and novel artificial-intelligence-derived metrics of cardiac contraction, and their relationship with MACE was investigated. Any of the 3 proposed directions demonstrated its additional prognostic value on top of established CMR indexes, myocardial injury markers, basic characteristics, and cardiovascular risk factors (P < 0.001). The combination of these 3 directions of enhancement towards a final CMR risk model improved MACE prediction by 13% compared to clinical baseline (0.774 (0.771-0.777) vs. 0.683 (0.681-0.685) cross-validated AUC, P < 0.001). The study evidences the contribution of the novel contraction characterization, enabled by a fully automated pipeline, to post-infarction assessment.

Contrast-enhanced cardiac MRI is superior to non-contrast mapping to predict left ventricular remodeling at 6 months after acute myocardial infarction

OBJECTIVES

Parametric mapping constitutes a novel cardiac magnetic resonance (CMR) technique enabling quantitative assessment of pathologic alterations of left ventricular (LV) myocardium. This study aimed to investigate the clinical utility of mapping techniques with and without contrast agent compared to standard CMR to predict adverse LV remodeling following acute myocardial infarction (AMI).

MATERIALS AND METHODS

A post hoc analysis was performed on sixty-four consecutively enrolled patients (57 ± 12 years, 54 men) with first-time reperfused AMI. Baseline CMR was obtained at 8 ± 5 days post-AMI, and follow-up CMR at 6 ± 1.4 months. T1/T2 mapping, T2-weighted, and late gadolinium enhancement (LGE) acquisitions were performed at baseline and cine imaging was used to determine adverse LV remodeling, defined as end-diastolic volume increase by 20% at 6 months.

RESULTS

A total of 11 (17%) patients developed adverse LV remodeling. At baseline, patients with LV remodeling showed larger edema (30 ± 11 vs. 22 ± 10%LV; p < 0.05), infarct size (24 ± 11 vs. 14 ± 8%LV; p < 0.001), extracellular volume (ECVinfarct; 63 ± 12 vs. 47 ± 11%; p < 0.001), and native T2infarct (95 ± 16 vs. 78 ± 17 ms; p < 0.01). ECVinfarct and infarct size by LGE were the best predictors of LV remodeling with areas under the curve (AUCs) of 0.843 and 0.789, respectively (all p < 0.01). Native T1infarct had the lowest AUC of 0.549 (p = 0.668) and was inferior to edema size by T2-weighted imaging (AUC = 0.720; p < 0.05) and native T2infarct (AUC = 0.766; p < 0.01).

CONCLUSION

In this study, ECVinfarct and infarct size by LGE were the best predictors for the development of LV remodeling within 6 months after AMI, with a better discriminative performance than non-contrast mapping CMR.

CLINICAL RELEVANCE STATEMENT

This study demonstrates the predictive value of contrast-enhanced and non-contrast as well as conventional and novel CMR techniques for the development of LV remodeling following AMI, which might help define precise CMR endpoints in experimental and clinical myocardial infarction trials.

KEY POINTS

• Multiparametric CMR provides insights into left ventricular remodeling at 6 months following an acute myocardial infarction. • Extracellular volume fraction and infarct size are the best predictors for adverse left ventricular remodeling. • Contrast-enhanced T1 mapping has a better predictive performance than non-contrast standard CMR and T1/T2 mapping.

Prognostic Value of Segmental Strain After ST-Elevation Myocardial Infarction: Insights From the EARLY Assessment of MYOcardial Tissue Characteristics by Cardiac Magnetic Resonance (EARLY-MYO-CMR) Study

BACKGROUND

The prognostic value of left ventricular segmental strain (SS) in ST-elevation myocardial infarction (STEMI) remains unclear.

HYPOTHESIS

To assess the prognostic value and application of SS.

STUDY TYPE

Retrospective analysis of a prospective registry.

POPULATION

Five hundred and forty-four patients after STEMI (500 in Cohort 1, 44 in Cohort 2).

FIELD STRENGTH/SEQUENCE

3 T, balanced steady-state free precession, gradient echo, and gradient echo contrast-enhanced images.

ASSESSMENT

Participants underwent cardiac MR during the acute phase after STEMI. Infarct-related artery (IRA) strain was determined based on SS obtained from cine images. The primary endpoint was the composite of major adverse cardiovascular events (MACEs) after 8 years of follow-up. In Cohort 2, SS stability was assessed by MR twice within 8 days. Contrast and non-contrast risk models based on SS were established, leading to the development of an algorithm.

STATISTICAL TEST

Student's t-test, Mann-Whitney U-test, Cox and logistic regression, Kaplan-Meier analysis, net reclassification index (NRI). P < 0.05 was considered significant.

RESULTS

During a median follow-up of 5.2 years, 83 patients from Cohort 1 experienced a MACE. Among SS, IRA peak circumferential strain (IRA-CS) was an independent factor for MACEs (adjusted hazard ratio 1.099), providing incremental prognostic value (NRI 0.180, P = 0.10). Patients with worse IRA-CS (>-8.64%) demonstrated a heightened susceptibility to MACE. Additionally, IRA-CS was significantly associated with microvascular obstruction (MVO) (adjusted odds ratio 1.084) and infarct size (r = 0.395). IRA-CS showed comparable prognostic effectiveness to global peak circumferential strain (NRI 0.100, P = 0.39), also counterbalancing contrast and non-contrast risk models (NRI 0.205, P = 0.05). In Cohort 2, IRA-CS demonstrated stability between two time points (P = 0.10). Based on risk models incorporating IRA-CS, algorithm "HJKL" was preliminarily proposed for stratification.

DATA CONCLUSIONS

IRA-CS is an important prognostic factor, and an algorithm based on it is proposed for stratification.

LEVEL OF EVIDENCE

4 TECHNICAL EFFICACY: Stage 2.

Culprit Lesion Vessel Size and Risk of Reperfusion Injury in ST-Segment Elevation Myocardial Infarction: A Cardiac Magnetic Resonance Imaging Study

BACKGROUND

Microvascular obstruction (MVO) and intramyocardial hemorrhage (IMH) are well-established imaging biomarkers of failed myocardial tissue reperfusion in patients with ST-segment elevation-myocardial infarction treated with percutaneous coronary intervention. MVO and IMH are associated with an increased risk of adverse outcome independent of infarct size, but whether the size of the culprit lesion vessel plays a role in the occurrence and severity of reperfusion injury is currently unknown. This study aimed to evaluate the association between culprit lesion vessel size and the occurrence and severity of reperfusion injury as determined by cardiac magnetic resonance imaging.

METHODS AND RESULTS

Patients (n=516) with first-time ST-segment-elevation myocardial infarction underwent evaluation with cardiac magnetic resonance at 4 (3-5) days after infarction. MVO was assessed with late gadolinium enhancement imaging and IMH with T2* mapping. Vessel dimensions were determined using catheter-based reference. Median culprit lesion vessel size was 3.1 (2.7-3.6) mm. MVO and IMH were found in 299 (58%) and 182 (35%) patients. Culprit lesion vessel size was associated with body surface area, diabetes, total ischemic time, postinterventional thrombolysis in myocardial infarction flow, and infarct size. There was no association between vessel size and MVO or IMH in univariable and multivariable analysis (P>0.05). These findings were consistent across patient subgroups with left anterior descending artery and non-left anterior descending artery infarctions and those with thrombolysis in myocardial infarction 3 flow post-percutaneous coronary intervention.

CONCLUSIONS

Comprehensive characterization of myocardial tissue reperfusion injury by cardiac magnetic resonance revealed no association between culprit lesion vessel size and the occurrence of MVO and IMH in patients treated with primary percutaneous coronary intervention for ST-segment-elevation myocardial infarction.

Association of dysglycaemia with persistent infarct core iron in patients with acute ST-segment elevation myocardial infarction

BACKGROUND

Dysglycaemia increases the risk of myocardial infarction and subsequent recurrent cardiovascular events. However, the role of dysglycaemia in ischemia/reperfusion injury with development of irreversible myocardial tissue alterations remains poorly understood. In this study we aimed to investigate the association of ongoing dysglycaemia with persistence of infarct core iron and their longitudinal changes over time in patients undergoing primary percutaneous coronary intervention (PCI) for acute ST-segment elevation myocardial infarction (STEMI).

METHODS

We analyzed 348 STEMI patients treated with primary PCI between 2016 and 2021 that were included in the prospective MARINA-STEMI study (NCT04113356). Peripheral venous blood samples for glucose and glycated hemoglobin (HbA1c) measurements were drawn on admission and 4 months after STEMI. Cardiac magnetic resonance (CMR) imaging including T2 * mapping for infarct core iron assessment was performed at both time points. Associations of dysglycaemia with persistent infarct core iron and iron resolution at 4 months were calculated using multivariable regression analysis.

RESULTS

Intramyocardial hemorrhage was observed in 147 (42%) patients at baseline. Of these, 89 (61%) had persistent infarct core iron 4 months after infarction with increasing rates across HbA1c levels (<5.7%: 33%, ≥5.7: 79%). Persistent infarct core iron was independently associated with ongoing dysglycaemia defined by HbA1c at 4 months (OR: 7.87 [95% CI: 2.60-23.78]; p < 0.001), after adjustment for patient characteristics and CMR parameters. The independent association was present even after exclusion of patients with diabetes (pre- and newly diagnosed, n = 16).

CONCLUSIONS

In STEMI patients treated with primary PCI, ongoing dysglycaemia defined by HbA1c is independently associated with persistent infarct core iron and a lower likelihood of iron resolution. These findings suggest a potential association between ongoing dysglycaemia and persistent infarct core iron, which warrants further investigation for therapeutic implications.

Infarct severity and outcomes in ST-elevation myocardial infarction patients without standard modifiable risk factors - A multicenter cardiac magnetic resonance study

BACKGROUND

Standard modifiable cardiovascular risk factors (SMuRFs) are well-established players in the pathogenesis of ST-elevation myocardial infarction (STEMI). However, in a significant proportion of STEMI patients, no SMuRFs can be identified, and the outcomes of this subgroup are not well described.

OBJECTIVES

To assess the infarct characteristics at myocardial-tissue level and subsequent clinical outcomes in SMuRF-less STEMIs.

METHODS

This multicenter, individual patient-data analysis included 2012 STEMI patients enrolled in four cardiac magnetic resonance (CMR) imaging studies conducted in Austria, Germany, Scotland, and the Netherlands. Unstable patients at time of CMR (e.g. cardiogenic shock/after cardiac arrest) were excluded. SMuRF-less was defined as absence of hypertension, smoking, hypercholesterolemia, and diabetes mellitus. All patients underwent CMR 3(interquartile range [IQR]:2-4) days after infarction to assess left ventricular (LV) volumes and ejection fraction, infarct size and microvascular obstruction (MVO). Clinical endpoints were defined as major adverse cardiovascular events (MACE), including all-cause mortality, re-infarction and heart failure.

RESULTS

No SMuRF was identified in 185 patients (9%). These SMuRF-less patients were older, more often male, had lower TIMI risk score and pre-interventional TIMI flow, and less frequently multivessel-disease. SMuRF-less patients did not show significant differences in CMR markers compared to patients with SMuRFs (all p > 0.10). During a median follow-up of 12 (IQR:12-27) months, 199 patients (10%) experienced a MACE. No significant difference in MACE rates was observed between SMuRF-less patients and patients with SMuRFs (8vs.10%, p = 0.39).

CONCLUSIONS

In this large individual patient-data pooled analysis of low-risk STEMI patients, infarct characteristics and clinical outcomes were not different according to SMuRF status.

Multi-parametric assessment of cardiac magnetic resonance images to distinguish myocardial infarctions: A tensor-based radiomics feature

AIM

This study assessed the myocardial infarction (MI) using a novel fusion approach (multi-flavored or tensor-based) of multi-parametric cardiac magnetic resonance imaging (CMRI) at four sequences; T1-weighted (T1W) in the axial plane, sense-balanced turbo field echo (sBTFE) in the axial plane, late gadolinium enhancement of heart short axis (LGE-SA) in the sagittal plane, and four-chamber views of LGE (LGE-4CH) in the axial plane.

METHODS

After considering the inclusion and exclusion criteria, 115 patients (83 with MI diagnosis and 32 as healthy control patients), were included in the present study. Radiomic features were extracted from the whole left ventricular myocardium (LVM). Feature selection methods were Least Absolute Shrinkage and Selection Operator (Lasso), Minimum Redundancy Maximum Relevance (MRMR), Chi-Square (Chi2), Analysis of Variance (Anova), Recursive Feature Elimination (RFE), and SelectPersentile. The classification methods were Support Vector Machine (SVM), Logistic Regression (LR), and Random Forest (RF). Different metrics, including receiver operating characteristic curve (AUC), accuracy, F1- score, precision, sensitivity, and specificity were calculated for radiomic features extracted from CMR images using stratified five-fold cross-validation.

RESULTS

For the MI detection, Lasso (as the feature selection) and RF/LR (as the classifiers) in sBTFE sequences had the best performance (AUC: 0.97). All features and classifiers of T1 + sBTFE sequences with the weighted method (as the fused image), had a good performance (AUC: 0.97). In addition, the results of the evaluated metrics, especially mean AUC and accuracy for all models, determined that the T1 + sBTFE-weighted fused method had strong predictive performance (AUC: 0.93±0.05; accuracy: 0.93±0.04), followed by T1 + sBTFE-PCA fused method (AUC: 0.85±0.06; accuracy: 0.84±0.06).

CONCLUSION

Our selected CMRI sequences demonstrated that radiomics analysis enables to detection of MI accurately. Among the investigated sequences, the T1 + sBTFE-weighted fused method with the highest AUC and accuracy values was chosen as the best technique for MI detection.

Potential utility of SPECT/CT with 99mTc-Tektrotyd for imaging of post-myocardial infarction inflammation

BACKGROUND

There is a need to develop methods for post-myocardial infarction (MI) inflammation monitoring. Scintigraphy with somatostatin receptor targeted radiotracers has potential in this field. The purpose was to study the association of 99mTc-Tektrotyd uptake intensity in MI area with heart contractility indices over 6-month follow-up.

METHODS

Fourteen patients with acute ST-segment elevation anterior MI (STEMI) were examined with 99mTc-Tektrotyd SPECT/CT, myocardial perfusion scintigraphy (MPS) at rest, cardiac magnetic resonance imaging (cMRI) and transthoracic echocardiography (TTE). Scintigraphic results were compared with 6-month TTE indices.

RESULTS

On the 7th day after a MI onset, cardiac 99mTc-Tektrotyd uptake was found in 7 of 14 patients. Median of 99mTc-Tektrotyd SUVmax was 1.59 (1.38; 2.83), the summed rest score (SRS) was 11 (5; 18), infarct size (by cMRI)-13.15 (3.3; 32.2) %. 99mTc-Tektrotyd SUVmax strongly correlated with 6-month heart contractility indices (r = 0.81, P < 0.05 for the end diastolic volume; r = 0.61 P < 0.05 for Δ end diastolic volume), with SRS (r = 0.85, P < 0.05) and infarct size (by cMRI) (r = 0.79, P < 0.05).

CONCLUSION

The intensity (SUVmax) of 99mTc-Tektrotyd uptake in the area of recent MI directly depends on the size of ischemic myocardial injury and correlates with changes of heart contractility indexes over the 6 month follow-up.

Temporal Trends in Infarct Severity Outcomes in ST-Segment-Elevation Myocardial Infarction: A Cardiac Magnetic Resonance Imaging Study

Background Severity of myocardial tissue injury is a main determinant of morbidity and death related to ST-segment-elevation myocardial infarction (STEMI). Temporal trends of infarct characteristics at the myocardial tissue level have not been described. This study sought to assess temporal trends in infarct characteristics through a comprehensive assessment by cardiac magnetic resonance imaging at a standardized time point early after STEMI. Methods and Results We analyzed patients with STEMI treated with percutaneous coronary intervention at the University Hospital of Innsbruck who underwent cardiac magnetic resonance imaging between 2005 and 2021. The study period was divided into terciles. Myocardial damage characteristics were assessed using a multiparametric cardiac magnetic resonance imaging protocol within the first week after STEMI and compared between groups. A total of 843 patients with STEMI (17% women) with a median age of 57 (interquartile range, 51-66) years were analyzed. While age, sex, and the clinical risk profile expressed as thrombolysis in myocardial infarction risk score were comparable across the study period, there were differences in guideline-recommended therapies. At the same time, there was no significant change in infarct size (P=0.25), microvascular obstruction (P=0.50), and intramyocardial hemorrhage (P=0.34). Left ventricular remodeling indices and left ventricular ejection fraction remained virtually unchanged (all P>0.05). Major adverse cardiovascular events at 4 (interquartile range, 4-5) months were similar between groups (P=0.36). Conclusions In this magnetic resonance imaging study investigating patients with STEMI treated with primary percutaneous coronary intervention over the past 15 years, no change in infarct severity at the myocardial level has been observed. Clinical research on novel therapeutic approaches to reduce myocardial tissue injury should be a priority.

3D Shape-Based Myocardial Infarction Prediction Using Point Cloud Classification Networks

Myocardial infarction (MI) is one of the most prevalent cardiovascular diseases with associated clinical decision-making typically based on single-valued imaging biomarkers. However, such metrics only approximate the complex 3D structure and physiology of the heart and hence hinder a better understanding and prediction of MI outcomes. In this work, we investigate the utility of complete 3D cardiac shapes in the form of point clouds for an improved detection of MI events. To this end, we propose a fully automatic multi-step pipeline consisting of a 3D cardiac surface reconstruction step followed by a point cloud classification network. Our method utilizes recent advances in geometric deep learning on point clouds to enable direct and efficient multi-scale learning on high-resolution surface models of the cardiac anatomy. We evaluate our approach on 1068 UK Biobank subjects for the tasks of prevalent MI detection and incident MI prediction and find improvements of ∼13% and ∼5% respectively over clinical benchmarks. Furthermore, we analyze the role of each ventricle and cardiac phase for 3D shape-based MI detection and conduct a visual analysis of the morphological and physiological patterns typically associated with MI outcomes.Clinical relevance- The presented approach enables the fast and fully automatic pathology-specific analysis of full 3D cardiac shapes. It can thus be employed as a real-time diagnostic tool in clinical practice to discover and visualize more intricate biomarkers than currently used single-valued metrics and improve predictive accuracy of myocardial infarction.

Prognostic value of pulmonary transit time by cardiac magnetic resonance imaging in ST-elevation myocardial infarction

OBJECTIVES

To investigate the prognostic value of pulmonary transit time (pTT) determined by cardiac magnetic resonance (CMR) after acute ST-segment-elevation myocardial infarction (STEMI).

METHODS

Comprehensive CMR examinations were performed in 207 patients 3 days and 4 months after reperfused STEMI. Functional parameters and infarct characteristics were assessed. PTT was defined as the interval between peaks of gadolinium contrast time-intensity curves in the right and left ventricles in first-pass perfusion imaging. Cox regression models were calculated to assess the association between pTT and the occurrence of major adverse cardiac events (MACE), defined as a composite of death, re-infarction, and congestive heart failure.

RESULTS

PTT was 8.6 s at baseline and 7.8 s at the 4-month CMR. In Cox regression, baseline pTT (hazard ratio [HR]: 1.58; 95% CI: 1.12 to 2.22; p = 0.009) remained significantly associated with MACE occurrence after adjustment for left ventricular ejection fraction (LVEF) and cardiac index. The association of pTT and MACE remained significant also after adjusting for infarct size and microvascular obstruction size. In Kaplan-Meier analysis, pTT ≥ 9.6 s was associated with MACE (p < 0.001). Addition of pTT to LVEF resulted in a categorical net reclassification improvement of 0.73 (95% CI: 0.27 to 1.20; p = 0.002) and integrated discrimination improvement of 0.07 (95% CI: 0.02 to 0.13; p = 0.007).

CONCLUSIONS

After reperfused STEMI, CMR-derived pTT was associated with hard clinical events with prognostic information independent of and incremental to infarct size and LV systolic function.

KEY POINTS

• Pulmonary transit time is the duration it takes the heart to pump blood from the right chambers across lung vessels to the left chambers. • This prospective single-centre study showed inferior outcome in patients with prolonged pulmonary transit time after myocardial infarction. • Pulmonary transit time assessed by magnetic resonance imaging added incremental information to established prognostic markers.

Predictive Value of Cardiac Magnetic Resonance for Left Ventricular Remodeling of Patients with Acute Anterior Myocardial Infarction

Background: Heart failure is a serious complication resulting from left ventricular remodeling (LVR), especially in patients experiencing acute anterior myocardial infarction (AAMI). It is crucial to explore the predictive parameters for LVR following primary percutaneous coronary intervention (PPCI) in patients with AAMI. Methods: A total of 128 AAMI patients who were reperfused successfully by PPCI were enrolled sequentially from June 2018 to December 2019. Cardiovascular magnetic resonance (CMR) was performed at the early stage (<7 days) and after the 6-month follow-up. The patients were divided into LVR and non-LVR groups according to the increase of left ventricular end diastolic volume (LVEDV) measured by the second cardiac magnetic resonance examination ≥20% from baseline. (3) Results: The left ventricular ejection fraction (LVEF), the global longitudinal strain (GLS), the peak circumferential strain in infarcted segments, and the infarct size (IS) remained significantly different in the multivariate logistic regression analysis (all p < 0.05). The area under the receiver operating characteristic curve of Model 1, wherein the GLS was added to the LVEF, was 0.832 (95% CI 0.758−0.907, p < 0.001). The C-statistics for Model 2, which included the infarct-related regional parameters (IS and the peak circumferential strain in infarcted segments)was 0.917 (95% CI 0.870−0.965, p < 0.001). Model 2 was statistically superior to Model 1 in predicting LVR (IDI: 0.190, p = 0.002). (4) Conclusions: Both the global and regional CMR parameters were valuable in predicting LVR in patients with AAMI following the PPCI. The local parameters of the infarct zones were superior to those of the global ones.

Cardiac Magnetic Resonance Features Associated with the Risk of Cardiac Arrest in Patients with Acute Myocardial Infarction

Background: Cardiac arrest (CA) is the most severe complication of acute myocardial infarction (AMI). Besides the location and severity of coronary occlusion, different factors may have significant role in the pathogenesis of AMI-related cardiac arrest (CA), but their contribution is still under investigation. The aim of the study was to investigate the cardiac magnetic resonance (CMR) features of myocardial injury associated with a higher risk of CA accompanying an AMI.

Methods: In total, 918 myocardial segments from 54 post-AMI patients undergoing CMR imaging with delayed gadolinium enhancement were enrolled in the study, of which 18.54% presented CA during the acute phase of AMI. In all patients, infarct mass, the proportion of high transmurality extent, and scar mass at different myocardial segments were calculated using QMap software (Medis BV).

Results: Compared to patients without CA, those with CA had a significantly higher infarct size (p = 0.03) and a higher degree of transmurality (29.28% vs. 14.1%, p = 0.01). The risk of CA during the acute phase was significantly higher in patients in whom the location of myocardial injury was at the level of latero-apical, antero-lateral, and basal anterior segments. Group 1 presented a larger infarct size at the level of the latero-apical (33.9 ± 30.6 g vs. 13.6 ± 17.3 g, p = 0.02), anterolateral (26.5 ± 29.0 g vs. 8.9 ± 12.8 g, p = 0.02), and anterobasal segment (20.1 ± 21.5 g vs. 7.8 ± 14.7 g, p = 0.02).

Conclusions: CMR imaging identified infarct mass, high transmurality degree, and large myocardial injury as features associated with an increased risk of CA in the acute phase of AMI, especially at the level of anterolateral segments.

Comparison of the Treatment Efficacy of Rosuvastatin versus Atorvastatin Loading Prior to Percutaneous Coronary Intervention in ST-Segment Elevation Myocardial Infarction

The aim of this study was to compare the effect of a single high-dose rosuvastatin versus atorvastatin preloading in ST-elevation myocardial infarction (STEMI) patients receiving primary percutaneous coronary intervention (PCI.) Methods: A total of 99 patients presented with STEMI and were randomly divided into three groups—a control group (n = 33) with no statin treatment, an atorvastatin group (n = 33) with a single 80 mg atorvastatin dose and the rosuvastatin group (n = 33) with a single 40 mg rosuvastatin dose in the emergency room (ER) prior to PCI. Post-interventional thrombolysis in myocardial infarction (TIMI) flow grade and corrected TIMI frame count (CTFC) were recorded, and ST-segment resolution was measured. Results: CTFC was significantly lower for the atorvastatin group (p-value < 0.01) than in the control group. A final TIMI flow grade 3 was achieved in 32 (97.0%) patients in the rosuvastatin group and 28 (84.8%) patients in the atorvastatin group compared with only 25 (75.8%) patients in the control group (p = 0.014). Peak CK-MB in the rosuvastatin group (263.2 [207.2−315.6]) and the atorvastatin group (208 [151.0−314.1]) was lower compared to that in the control group (398.4 [303.9−459.3]); p < 0.001. Conclusions: A single extensive dose of lipophilic atorvastatin prior to primary PCI in STEMI patients showed better improvement in microvascular myocardial perfusion compared to hydrophilic rosuvastatin.

Development and validation of a predictive model for adverse left ventricular remodeling in NSTEMI patients after primary percutaneous coronary intervention

Introduction

To develop and validate clinical evaluators that predict adverse left ventricular remodeling (ALVR) in non-ST-elevation myocardial infarction (NSTEMI) patients after primary percutaneous coronary intervention (PCI).

Methods

The retrospective study analyzed the clinical data of 507 NSTEMI patients who were treated with primary PCI from the Affiliated Hospital of Xuzhou Medical University and the Second Affiliated Hospital of Xuzhou Medical University, between January 1, 2019 and September 31, 2021. The training cohort consisted of patients admitted before June 2020 (n = 287), and the remaining patients (n = 220) were assigned to an external validation cohort. The endpoint event was the occurrence of ALVR, which was described as an increase ≥ 20% in left ventricular end-diastolic volume (LVEDV) at 3–4 months follow-up CMR compared with baseline measurements. The occurrence probability of ALVR stemmed from the final model, which embodied independent predictors recommended by logistic regression analysis. The area under the receiver operating characteristic curve (AUC), Calibration plot, Hosmer–Lemeshow method, and decision curve analysis (DCA) were applied to quantify the performance.

Results

Independent predictors for ALVR included age (odds ratio (OR): 1.040; 95% confidence interval (CI): 1.009–1.073), the level of neutrophil to lymphocyte ratio (OR: 4.492; 95% CI: 1.906–10.582), the cardiac microvascular obstruction (OR: 3.416; 95% CI: 1.170–9.970), peak global longitudinal strain (OR: 1.131; 95% CI: 1.026–1.246), infarct size (OR: 1.082; 95% CI: 1.042–1.125) and left ventricular ejection fraction (OR: 0.925; 95% CI: 0.872–0.980), which were screened by regression analysis then merged into the nomogram model. Both internal validation (AUC: 0.805) and external validation (AUC: 0.867) revealed that the prediction model was capable of good discrimination. Calibration plot and Hosmer–Lemeshow method showed high consistency between the probabilities predicted by the nomogram (P = 0.514) and the validation set (P = 0.762) and the probabilities of actual occurrence. DCA corroborated the clinical utility of the nomogram.

Conclusions

In this study, the proposed nomogram model enabled individualized prediction of ALVR in NSTEMI patients after reperfusion and conduced to guide clinical therapeutic schedules.

Cardiac Magnetic Resonance Shows Improved Outcomes in Patients with an ST-Segment Elevation Myocardial Infarction and a High Thrombus Burden Treated with Adjuvant Aspiration Thrombectomy

There is a discrepancy between epicardial vessel patency and microcirculation perfusion in a third of patients treated with percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI). Optimization with aspiration thrombectomy (AT) may reduce distal embolization and microvascular obstruction. The effect of AT in the treatment of STEMI is debatable. The purpose of this study was to use cardiac magnetic resonance (CMR) to determine whether AT influences microvascular obstruction (MVO), infarct size and left ventricular (LV) remodelling in STEMI patients. Sixty STEMI patients with a thrombus-occluded coronary artery were randomized in a 2:1 fashion to receive PCI proceeded by AT (AT + PCI group), or PCI only. MVO, myocardial infarct size and LV remodelling were assessed by CMR during the index hospitalization and 6 months thereafter. The majority of patients had a large thrombus burden (TIMI thrombus grade 5 in over 70% of patients). PCI and AT were effective in all cases. There were no periprocedural strokes. CMR showed that the addition of AT to standard PCI was associated with lesser MVO when indexed to the infarct size and larger infarct size reduction. There were less patients with left ventricle remodelling in the AT + PCI vs. the PCI only group. To conclude, in STEMI patients with a high thrombus burden, AT added to PCI is effective in reducing infarct size, MVO and LV remodelling.

Neuropeptide-Y Levels in ST-Segment-Elevation Myocardial Infarction: Relationship With Coronary Microvascular Function, Heart Failure, and Mortality

Background

The sympathetic cotransmitter, neuropeptide Y (NPY), is released into the coronary sinus during ST‐segment–elevation myocardial infarction and can constrict the coronary microvasculature. We sought to establish whether peripheral venous (PV) NPY levels, which are easy to obtain and measure, are associated with microvascular obstruction, myocardial recovery, and prognosis.

Methods and Results

NPY levels were measured immediately after primary percutaneous coronary intervention and compared with angiographic and cardiovascular magnetic resonance indexes of microvascular function. Patients were prospectively followed up for 6.4 (interquartile range, 4.1–8.0) years. PV (n=163) and coronary sinus (n=68) NPY levels were significantly correlated (r=0.92; P<0.001) and associated with multiple coronary and imaging parameters of microvascular function and infarct size (such as coronary flow reserve, acute myocardial edema, left ventricular ejection fraction, and late gadolinium enhancement 6 months later). We therefore assessed the prognostic value of PV NPY during follow‐up, where 34 patients (20.7%) developed heart failure or died. Kaplan‐Meier survival analysis demonstrated that high PV NPY levels (>21.4 pg/mL by binary recursive partitioning) were associated with increased incidence of heart failure and mortality (hazard ratio, 3.49 [95% CI, 1.65–7.4]; P<0.001). This relationship was maintained after adjustment for age, cardiovascular risk factors, and previous myocardial infarction.

Conclusions

Both PV and coronary sinus NPY levels correlate with microvascular function and infarct size after ST‐segment–elevation myocardial infarction. PV NPY levels are associated with the subsequent development of heart failure or mortality and may therefore be a useful prognostic marker. Further research is required to validate these findings.

Value of Fast MVO Identification From Contrast-Enhanced Cine (CE-SSFP) Combined With Myocardial Strain in Predicting Adverse Events in Patients After ST-Elevation Myocardial Infarction

Objectives

Cardiac magnetic resonance imaging (CMR) can be used for a one-step evaluation of myocardial function and pathological features after acute ST-elevation myocardial infarction (STEMI). We aimed to evaluate the value of fast microvascular occlusion (MVO) identification from contrast-enhanced steady-state free precession (CE-SSFP) combined with myocardial strain in predicting major cardiovascular adverse events (MACEs) in primary percutaneous coronary intervention (pPCI) patients with STEMI.

Methods

In total, 237 patients with STEMI who received pPCI and completed CMR scans within the following week were enrolled, MVO identification and the myocardial strain analysis were performed in CE-SSFP images without an additional method. The primary endpoint was the presence of MACE, which is defined as a composite of death, reinfarction, and congestive heart failure (HF).

Results

After 13 months of follow-up [interquartile range (IQR): 11-24], 30 patients (14%) developed MACE; the MVO (hazard ratio (HR) was 3.10; 95% CI: 1.14-8.99, p = 0.028), and the infarct size (IS) (HR: 1.03; 95% CI: 1.0-1.06, p = 0.042) and global longitudinal strain (GLS) (HR: 1.08; 95% CI: 1.01-1.17, p = 0.029) were finally associated with MACE. Receiver operating characteristic (ROC) analyses show that the area under the curve (AUC) of GLS was large (0.73 [95% CI, 0.63-0.82], p = 0.001), and the best cut-off was -11.8%, with 76.7% sensitivity and 58.9% specificity, which are greater than those of IS (0.70, 95% CI, 0.60-0.81, p < 0.001) and MVO (0.68, 95% CI, 0.58-0.78, p < 0.001). However, combining MVO and GLS resulted in a much greater finding (AUC = 0.775, 95% CI: 0.727-0.824, p < 0.001) and better sensitivity and specificity (83.3%, 66.5%).

Conclusion

Microvascular occlusion identification from contrast-enhanced cine combined with myocardial strain could be a quick and reliable option for patients with STEMI who underwent pPCI; it correlates well with the prognosis of patients with STEMI in terms of MACE.

Case Report: ST-Elevation Myocardial Infarction Secondary to Acute Atherothrombotic Occlusion Treated With No Stent Strategy

Background

Intravascular imaging plays a vital role in the pathophysiology-based diagnosis and treatment of patients with ST-elevation myocardial infarction (STEMI). We present a case of STEMI due to plaque erosion, which was managed with a no stent approach.

Case Summary

A 43-year-old female with a history of tobacco abuse presented with an anterior STEMI. Coronary angiography revealed acute thrombotic occlusion of the left anterior descending artery with spontaneous recanalization. Intravascular imaging with optical coherence tomography (OCT) demonstrated plaque erosion as the underlying etiology for the acute thrombotic occlusion. A no stent strategy with aspiration thrombectomy and dual antiplatelet therapy was used to manage the patient given that there was no evidence of plaque rupture. Repeat coronary imaging was done at 2 months to assess the status of the lesion.

Conclusion

A 43-year-old female with STEMI due to plaque erosion was successfully managed only by thrombus aspiration and not by angioplasty and stent placement. Individualized treatment approaches in patients with acute coronary syndromes, can not only achieve optimal management goals but also avoid unnecessary complications associated with interventions. This case illustrates how intracoronary imaging and pathophysiology-guided treatment can dramatically change management. In this young patient, STEMI was managed purely by thrombus aspiration. Intravascular imaging obviated the need for stent placement possibly preventing stent-related complications including restenosis and thrombosis.

Association of plasma interleukin-6 with infarct size, reperfusion injury, and adverse remodelling after ST-elevation myocardial infarction

AIMS

Little is known about the clinical relevance of interleukin (IL)-6 in patients with acute ST-elevation myocardial infarction (STEMI). This study examined the possible associations of plasma IL-6 concentrations with infarct size (IS), reperfusion injury and adverse left ventricular remodelling (LVR), in STEMI patients treated with primary percutaneous coronary intervention (PCI).

METHODS AND RESULTS

We prospectively included 170 consecutive STEMI patients (median age 57 years, 14% women) treated with primary PCI between 2017 and 2019. Blood samples for biomarker analyses including IL-6 were collected on Day 2. Left ventricular ejection fraction (LVEF), IS, and reperfusion injury [microvascular obstruction (MVO) and intramyocardial haemorrhage (IMH)] were determined using cardiac magnetic resonance (CMR) imaging on Day 4. Left ventricular remodelling was defined as ≥10% increase in left ventricular end-diastolic volume from baseline to 4 months CMR follow-up. Patients with IL-6 concentrations ≥median (17 ng/L) showed a significantly lower LVEF (43% vs. 52%, P < 0.001), larger IS (22% vs. 13%, P < 0.001), larger MVO (1.9% vs. 0.0%, P < 0.001), and more frequent IMH (52% vs. 18%, P < 0.001). Left ventricular remodelling was more common in patients with IL-6 ≥ median (24% vs. 9%, P = 0.005). In both linear and binary multivariable regression analyses, IL-6 remained independently associated with lower LVEF [odds ratio (OR): 0.10, 95% confidence interval (CI) 0.02-0.42, P = 0.002], larger IS (OR: 5.29, 95% CI 1.52-18.40, P = 0.009), larger MVO (OR: 5.20, 95% CI 1.30-20.85, P = 0.020), with presence of IMH (OR: 3.73, 95% CI 1.27-10.99, P = 0.017), and adverse LVR (OR: 2.72, 95% 1.06-6.98, P = 0.038).

CONCLUSIONS

High concentrations of circulating plasma IL-6 on Day 2 after STEMI were independently associated with worse myocardial function, larger infarct extent, more severe reperfusion injury, and a higher likelihood for LVR, suggesting IL-6 as a useful biomarker of more serious outcome and potential therapeutic target.

CLINICAL TRIAL REGISTRATION

https://clinicaltrials.gov/ct2/show/NCT04113356;NCT04113356.

Magnitude of ST-segment Elevation Is Associated with Increased Acute Inflammatory Response and Myocardial Scar in Patients with Acute Myocardial Infarction Undergoing pPCI

Background: The integrated ST segment elevation score (ISSTE) score objectively quantifies the ECG changes before and after primary percutaneous coronary intervention (pPCI) for ST segment elevation myocardial infarction (STEMI). The inflammatory response is a major component in scar formation and remodeling process of the myocardial tissue following myocardial infarction (MI). Cardiac magnetic resonance imaging (CMR) precisely quantifies the cardiac function and assesses the pattern of the myocardial scar tissue. The aim of the study was to evaluate the relations between the ISSTE score and: (1) acute inflammatory biomarkers and (2) extent of the myocardial scar determined by CMR in STEMI treated with pPCI. Material and methods: One hundred thirty STEMI patients were included in the study, who underwent pPCI in the first 12 hours from symptom debut. ISSTE-1 was calculated at presentation and 2 hours following pPCI (ISSTE-2). Inflammatory biomarkers were determined at admission and day 5, followed by LGE-CMR at 4 weeks, with quantification of cardiac function and extent of infarct size (IS) and transmurality. Patients were divided in low and high ISSTE groups based on the median values. Results: No significant differences were noted in terms of CMR parameters or inflammatory biomarkers and between the groups with low or high ISSTE-1. Significantly higher levels of day-5 hs-CRP (p = 0.03) and day-1 IL-6 (p = 0.02), MMP-9 (p = 0.05) were recorded in high ISSTE-2 groups. LV IS mass (23.11 ± 5.31 vs. 57.94 ± 8.33, p = 0.001), percentage (13.55 ± 6.22 vs. 27.15 ± 7.12, p = 0.001) and transmurality (p = 0.001) was significantly higher in ISSTE-2 group. ISSTE-2 significantly correlated with LV IS mass (r = 0.391, p <0.0001), percentage (r = 0.541, p <0.0001) high transmurality (r = 0.449, p <0.0001) and LV EF (r = -0.397, p <0.0001). Conclusions: A high ISSTE-2 score is associated with increased inflammatory response exhibited by elevated serum IL-6 and MMP-9 levels determined on the day of admission, and with persistently increased serum hs-CRP levels on day 5 of the acute event. A higher ISSTE-2 score is associated with larger myocardial scar extent expressed by IS, higher transmurality and reduced LV EF at 1-month LGE CMR follow-up.

Global longitudinal strain improves risk assessment after ST-segment elevation myocardial infarction: a comparative prognostic evaluation of left ventricular functional parameters

AIM

We aimed to investigate the comparative prognostic value of left ventricular ejection fraction (LVEF), mitral annular plane systolic excursion (MAPSE), fast manual long-axis strain (LAS) and global longitudinal strain (GLS) determined by cardiac magnetic resonance (CMR) in patients after ST-segment elevation myocardial infarction (STEMI).

METHODS AND RESULTS

This observational cohort study included 445 acute STEMI patients treated with primary percutaneous coronary intervention (pPCI). Comprehensive CMR examinations were performed 3 [interquartile range (IQR): 2-4] days after pPCI for the determination of left ventricular (LV) functional parameters and infarct characteristics. Primary endpoint was the occurrence of major adverse cardiac events (MACE) defined as composite of death, re-infarction and congestive heart failure. During a follow-up of 16 [IQR: 12-49] months, 48 (11%) patients experienced a MACE. LVEF (p = 0.023), MAPSE (p < 0.001), LAS (p < 0.001) and GLS (p < 0.001) were significantly related to MACE. According to receiver operating characteristic analyses, only the area under the curve (AUC) of GLS was significantly higher compared to LVEF (0.69, 95% confidence interval (CI) 0.64-0.73; p < 0.001 vs. 0.60, 95% CI 0.55-0.65; p = 0.031. AUC difference: 0.09, p = 0.020). After multivariable analysis, GLS emerged as independent predictor of MACE even after adjustment for LV function, infarct size and microvascular obstruction (hazard ratio (HR): 1.13, 95% CI 1.01-1.27; p = 0.030), as well as angiographical (HR: 1.13, 95% CI 1.01-1.28; p = 0.037) and clinical parameters (HR: 1.16, 95% CI 1.05-1.29; p = 0.003).

CONCLUSION

GLS emerged as independent predictor of MACE after adjustment for parameters of LV function and myocardial damage as well as angiographical and clinical characteristics with superior prognostic validity compared to LVEF.

Can Fetuin A Be Utilized in the Evaluation of Elderly Patients with Acute Myocardial Infarction?

Background: Lower baseline Fetuin-A (FA) is associated with left ventricular remodeling and cardiovascular death (CVD) at 4 months after acute myocardial infarction (AMI). However, the association between FA levels, incomplete ST segment resolution (STR) following primary percutaneous coronary intervention (PCI) and early mortality in AMI has not been previously studied. Methods: We enrolled 100 patients with AMI, which we divided in two groups: 21 patients who suffered sudden cardiac death (SCD) in the first 7 days after PCI and 79 controls. We measured FA, NT-proBNP and troponin levels and correlated them with the occurrence of death in the first week after revascularization. We also tested the cut-off value of FA to determine STR at 90 min after PCI. Results: SCD was most frequently caused by pump failure (n = 10, 47.6%) and ventricular arrhythmias (n = 9, 42.5%). Plasma FA levels correlated with NT-proBNP values (r = −0.47, p = 0.04) and were significantly lower in patients presenting SCD (115 (95–175) vs. 180 (105–250) ng/mL, p = 0.03). Among all three biomarkers, FA was the only one associated with incomplete STR after PCI on the multivariate logistic regression (cut-off value of 175 ng/mL, Se = 74%, Sp = 61.1%). Death rate was highest (n = 16/55, 30%) in patients with FA levels below the cut-off value of 175 ng/mL. Conclusion: Lower FA is associated with higher early mortality and incomplete STR after primary percutaneous revascularization in patients with AMI. Measurement of FA levels in addition to NT-proBNP, troponin and STR might enable more accurate identification of high-risk patients.

C-reactive protein velocity predicts microvascular pathology after acute ST-elevation myocardial infarction

BACKGROUND

The role of C-reactive protein velocity (CRPv) as an early and sensitive marker of an excessive inflammatory response in the setting of acute ST-elevation myocardial infarction (STEMI) is only poorly understood. The aim of this study was to investigate, in patients with STEMI treated with primary percutaneous coronary intervention (PCI), the association of CRPv with microvascular infarct pathology.

METHODS AND RESULTS

This prospective cohort study included a total of 316 patients with STEMI undergoing PCI. CRPv was defined as the difference between CRP 24 ± 8 h and CRP at hospital admission, divided by the time (in h) that have passed during the two examinations. The association of biomarker levels with cardiac magnetic resonance (CMR)-determined microvascular obstruction (MVO) was evaluated. CMR was performed at a median of 3 [interquartile range 2-4] days after PCI. After adjustment for cardiac troponin T (cTnT), anterior infarction and TIMI flow pre and post-PCI, CRPv (odds ratio 2.70, 95% confidence interval (CI) 1.54-4.73; p = 0.001) remained significantly associated with the occurrence of MVO. CRPv (area under the curve [AUC] 0.76, 95% CI 0.71-0.81; p < 0.001) was a better predictor for MVO compared to 24 h CRP (AUC difference: 0.03, p = 0.002). The addition of CRPv to peak cTnT resulted in a higher AUC for MVO prediction than peak cTnT alone (AUC 0.86, 95% CI 0.82-0.90; p < 0.001 vs. AUC 0.84, 95% CI 0.79-0.88; p < 0.001. AUC difference: 0.02, p = 0.042).

CONCLUSIONS

In patients with STEMI treated with primary PCI, CRPv was associated with microvascular infarct pathology with a predictive value incremental to cTnT, suggesting CRPv as an early and sensitive biomarker for more severe infarct pathology and outcome.

Every minute counts: in-hospital changes of left ventricular regional and global function in patients with ST-segment elevation myocardial infarction

AIMS

The aim of our study was to assess the effects of an early percutaneous coronary intervention on changes of in-hospital left ventricular ejection fraction (LVEF) and wall motion score index (WMSI) in patients with ST-segment elevation myocardial infarction.

METHODS

The study population consisted of 324 consecutive patients with ST-segment elevation myocardial infarction undergoing percutaneous coronary intervention, divided into two groups, according to the first medical contact (FMC)-to-reperfusion time, respectively, 90 min or less (n = 173) and more than 90 min (n = 151). Moreover, we performed a sub-analysis in the group of patients who showed at discharge an improvement in the LVEF of at least 10%.

RESULTS

In both groups at baseline, patients suffered from a moderately reduced LVEF (40.88 ± 8.38% in ≤90 min group vs. 40.70 ± 8.98% in >90 min group; P = 0.858). A WMSI of more than 1 was recorded uniformly: 1.71 ± 0.37 in patients with FMC-to-reperfusion 90 min or less and 1.72 ± 0.38 in patients more than 90 min (P = 0.810). At the time of discharge, a significant improvement in LVEF (43.82 ± 8.38%, P = 0.001) and WMSI (1.60 ± 0.41, P = 0.009) exclusively emerged in the 90 min or less group. Furthermore, we identified 105 patients who experienced an improvement in the LVEF of at least 10% compared with baseline values. In these patients FMC-to-reperfusion and total ischemic time resulted as significantly shorter, when compared with patients with LVEF improvement of less than 10%.

CONCLUSION

Our study confirms and reinforces the concept that reducing the duration of the time between FMC and reperfusion, as well as the total ischemic time influences a positive recovery of left ventricular global and regional function during in-hospital stay.

Effect of the COVID-19 Pandemic on Treatment Delays in Patients with ST-Segment Elevation Myocardial Infarction

Coronavirus disease 19 (COVID-19) and its associated restrictions could affect ischemic times in patients with ST-segment elevation myocardial infarction (STEMI). The objective of this study was to investigate the influence of the COVID-19 outbreak on ischemic times in consecutive all-comer STEMI patients. We included consecutive STEMI patients (n = 163, median age: 61 years, 27% women) who were referred to seven tertiary care hospitals across Austria for primary percutaneous coronary intervention between 24 February 2020 (calendar week 9) and 5 April 2020 (calendar week 14). The number of patients, total ischemic times and door-to-balloon times in temporal relation to COVID-19-related restrictions and infection rates were analyzed. While rates of STEMI admissions decreased (calendar week 9/10 (n = 69, 42%); calendar week 11/12 (n = 51, 31%); calendar week 13/14 (n = 43, 26%)), total ischemic times increased from 164 (interquartile range (IQR): 107-281) min (calendar week 9/10) to 237 (IQR: 141-560) min (calendar week 11/12) and to 275 (IQR: 170-590) min (calendar week 13/14) (p = 0.006). Door-to-balloon times were constant (p = 0.60). There was a significant difference in post-interventional Thrombolysis in myocardial infarction (TIMI) flow grade 3 in patients treated during calendar week 9/10 (97%), 11/12 (84%) and 13/14 (81%; p = 0.02). Rates of in-hospital death and re-infarction were similar between groups (p = 0.48). Results were comparable when dichotomizing data on 10 March and 16 March 2020, when official restrictions were executed. In this cohort of all-comer STEMI patients, we observed a 1.7-fold increase in ischemic time during the outbreak of COVID-19 in Austria. Patient-related factors likely explain most of this increase. Counteractive steps are needed to prevent further cardiac collateral damage during the ongoing COVID-19 pandemic.