Detection and Classification of Myocardial Infarction Transmurality Using Cardiac MR Image Analysis and Machine Learning Algorithms.

The presence of abnormalities when the left ventricle is deformed is related to the patients' prognosis after a first myocardial infarction. These deformations can be detected by performing a cardiac magnetic resonance (CMR) study. Currently, late gadolinium enhancement (LGE) is considered to be the gold standard when performing CMR imaging. However, CMR with LGE overestimates infarct size and underestimates recovery of dysfunctional segments after myocardial infarction. Based on this statement, the objective is to detect, characterize, and quantify the extent of myocardial infarction in patients with cardiac pathologies, using parameters derived from CMR, in order to obtain greater precision in patients' recovery predictions than when only studying LGE images. For this purpose, we studied the infarct presence and extension from a total of 105 images from 35 patients, and calculated myocardium strain and torsion to characterize and quantify the affected tissue. A total of twenty-one parameters were selected to create predictive models. Moreover, we compared two feature extraction methods, and the performance of five machine learning algorithms. Results show that both temporal and strain parameters are the most relevant to detect and characterize the extent of myocardial infarction. The use of imaging techniques and machine learning algorithms have great potential and show promising results when it comes to detecting the presence and extent of myocardial infarction. The current study proposes a novel approach to detect, quantify, and characterize cardiac infarction by using strain and torsion parameters from different CMR images and different Machine Learning algorithms. This would potentially overcome LGE, the current state of the art technique, in estimating the extension of damaged tissue and enable an objective diagnosis and clinical decision.

Synthetic Generation of Cardiac MR Images Combining Convolutional Variational Autoencoders and Style Transfer.

The number of studies in the medical field that uses machine learning and deep learning techniques has been increasing in the last years. However, these techniques require a huge amount of data that can be difficult and expensive to obtain. This specially happens with cardiac magnetic resonance (MR) images. One solution to the problem is raise the dataset size by generating synthetic data. Convolutional Variational Autoencoder (CVAe) is a deep learning technique which allows to generate synthetic images, but sometimes the synthetic images can be slightly blurred. We propose the combination of the CVAe technique combined with Style Transfer technique to generate synthetic realistic cardiac MR images. Clinical Relevance-The current work presents a tool to increase in a simple easy and fast way the cardiac magnetic resonance images dataset with which perform machine learning and deep learning studies.

Exercise ECG Testing and Stress Cardiac Magnetic Resonance for Risk Prediction in Patients With Chronic Coronary Syndrome.

PURPOSE: Vasodilator stress cardiac magnetic resonance (VS-CMR) has become crucial in the workup of patients with known or suspected chronic coronary syndrome (CCS). Whether traditional exercise ECG testing (ExECG) contributes prognostic information beyond VS-CMR is unclear. METHODS: We retrospectively included 288 patients with known or suspected CCS who had undergone ExECG and subsequent VS-CMR in our institution. Clinical, ExECG, and VS-CMR variables were recorded. We defined the serious adverse events (SAE) as a combined endpoint of acute coronary syndrome, admission for heart failure, or all-cause death. RESULTS: During a mean follow-up of 4.2 ± 2.15 yr, we registered 27 SAE (15 admissions for acute coronary syndrome, eight admissions for heart failure, and four all-cause deaths). Once adjusted for clinical, ExECG, and VS-CMR parameters associated with SAE, the only independent predictors were HRmax in ExECG (HR = 0.98: 95% CI, 0.96-0.99; P = .01) and more extensive stress-induced perfusion defects (PDs, number of segments) in VS-CMR (HR = 1.19: 95% CI, 1.07-1.34; P < .01). Adding HRmax significantly improved the predictive power of the multivariable model for SAE, including PDs (continuous reclassification improvement index: 0.47: 95% CI, 0.10-0.81; P < .05). The annualized SAE rate was 1% (if PD < 2 segments and HRmax > 130 bpm), 2% (if PD < 2 segments and HRmax ≤ 130 bpm), 3.2% (if PD ≥ 2 segments and HRmax > 130 bpm), and 6.3% (if PD ≥ 2 segments and HRmax ≤ 130 bpm), P < .01, for the trend. In patients on ß-blocker therapy, however, only PDs in VS-CMR, but not HRmax, predicted SAE. CONCLUSIONS: We conclude that ExECG contributes significantly to prognostic information beyond VS-CMR in patients with known or suspected CCS.

Cardiac sarcoidosis as an incidental finding: A case report.

BACKGROUND: This case illustrates the evaluation of a healthy young male with ECG anomalies in a perioperative electrocardiogram (ECG) that ended up with the diagnosis of a severe systemic disease. CASE: A 28-year-old man was attended at the outpatient cardiology department to perform a preoperative ECG for lacrimal duct obstruction surgery, which showed Q and T negative waves in inferior leads. Echocardiogram and cardiac magnetic resonance (CMR) displayed left ventricular (LV) aneurysm at basal segments of the inferior, posterior, and lateral wall with myocardial thinning and dyskinesia. CMR and thoracic computed tomography (CT) showed bilateral nodular images in parotid glands, cervical, and thoracic lymphadenopathies. All those findings suggested the diagnosis of sarcoidosis, which was supported by Gallium-67 single-photon emission computed tomography (SPECT) results and finally confirmed by skin biopsy. CONCLUSIONS: The present case highlights the complexity of sarcoidosis diagnosis. This young male was apparently asymptomatic; however, at presentation, he actually had three manifestations of active sarcoidosis: lacrimal duct obstruction, skin lesions, and cervical lymphadenopathies. It is essential to have a low threshold for sarcoidosis suspicion in the setting of unexplained systemic signs and symptoms.

Role of PCSK9 in the course of ejection fraction change after ST-segment elevation myocardial infarction: a pilot study.

AIMS: Proprotein convertase subtilisin/kexin type 9 (PCSK9) has emerged as a therapeutic target for reducing plasma low-density lipoprotein cholesterol. Beyond lipid control, recent findings suggest a deleterious effect of this protein in the pathogenesis of postmyocardial infarction left ventricle remodelling and heart failure-related complications. The aim of this study was to assess the relationship between circulating PCSK9 and 6 month cardiac magnetic resonance imaging-derived left ventricular ejection fraction (LVEF) after a first ST-segment elevation myocardial infarction (STEMI). METHODS AND RESULTS: We prospectively evaluated 40 patients with a first STEMI, LVEF < 50% and treated with primary percutaneous coronary intervention in which PCSK9 was measured 24 h postreperfusion. All patients underwent cardiac magnetic resonance imaging 1 week and 6 months after STEMI. Baseline characteristics were compared across median values of PCSK9. The association between PCSK9 levels and LVEF at 6 months was evaluated by analysis of covariance. The mean age of the sample was 60 ± 12 years and 33 (82.5%) were male patients. The infarct location was anterior in 27 patients (67.5%), and 9 patients (22.5%) were Killip class ≥ II. The mean 1 week and 6 month LVEF were 41 ± 7% and 48 ± 10%, respectively. The mean PCSK9 was 1.93 ± 0.38 U/mL. Testing the association between serum PCSK9 and 6 month LVEF with analysis of covariance revealed an inverse relationship (r = -0.35, P = 0.028). After multivariate adjustment, circulating PCSK9 remained significant and inversely associated with 6 month LVEF (P = 0.002). CONCLUSIONS: In patients with a first STEMI with reduced ejection fraction at index admission and treated with primary percutaneous coronary intervention, circulating PCSK9 was associated with lower LVEF at 6 months.

ST2 and left ventricular remodeling after ST-segment elevation myocardial infarction: A cardiac magnetic resonance study.

BACKGROUND: The association of soluble interleukin-1 receptor-like 1 (ST2) with left ventricular (LV) remodeling is unclear in patients with a first ST-segment elevation myocardial infarction (STEMI). The objective of this work was to assess the relationship between ST2, a marker of inflammation, and cardiac magnetic resonance (CMR) imaging-derived LV remodeling after a first STEMI. METHODS: We prospectively evaluated 109 patients with a first STEMI treated with primary percutaneous coronary intervention who had ST2 assessed 24 h post-reperfusion. All patients underwent CMR imaging 1 week and 6 months after STEMI. The independent associations between ST2, LV diastolic and systolic volume indices, and LV ejection fraction (LVEF) were evaluated by linear mixed models. RESULTS: The mean age of the sample was 59 ±â€¯12 years, 85 patients (78%) were male, and 13 (11.9%) had a LVEF ≤40%. The median (IQR) of ST2 was 55.3 (38.7-94.1) pg/mL. At 1-week CMR higher ST2 was related to more infarct size and less myocardial salvage index (p < 0.01). Overall, after comprehensive multivariable adjustment, higher baseline ST2 was associated with progressive LV volume indices dilation and LVEF deterioration (p < 0.05). This effect was stronger in patients with severe 1-week structural damage, namely those with large infarct size, extensive microvascular obstruction or LVEF ≤40%. CONCLUSIONS: In patients with a first STEMI treated with primary percutaneous coronary intervention, soluble ST2 predicts dynamic changes in CMR-derived LV volumes and LVEF. Future studies must assess whether targeting interleukin-1 leads to lower ST2 levels and less LV remodeling.

Changes in myocardial iron content following administration of intravenous iron (Myocardial-IRON): Study design.

Treatment with intravenous ferric carboxymaltose (FCM) has been shown to improve symptoms, functional capacity, and quality of life in patients with heart failure and iron deficiency. However, the underlying mechanisms for these beneficial effects remain undetermined. The aim of this study is to quantify cardiac magnetic resonance changes in myocardial iron content after administration of intravenous FCM in patients with heart failure and iron deficiency and contrast them with parameters of heart failure severity. This is a multicenter, double-blind, randomized study. Fifty patients with stable symptomatic heart failure, left ventricular ejection fraction <50%, and iron deficiency will be randomly assigned 1:1 to receive intravenous FCM or placebo. Intramyocardial iron will be evaluated by T2* and T1 mapping cardiac magnetic resonance sequences before and at 7 and 30 days after FCM. After 30 days, patients assigned to placebo will receive intravenous FCM in case of persistent iron deficiency. The main endpoint will be changes from baseline in myocardial iron content at 7 and 30 days. Secondary endpoints will include the correlation of these changes with left ventricular ejection fraction, functional capacity, quality of life, and cardiac biomarkers. The results of this study will add important knowledge about the effects of intravenous FCM on myocardial tissue and cardiac function. We hypothesize that short-term (7 and 30 days) myocardial iron content changes after intravenous FCM, evaluated by cardiac magnetic resonance, will correlate with simultaneous changes in parameters of heart failure severity. The study is registered at http://www.clinicaltrials.gov (NCT03398681).

Incidence, Outcomes, and Predictors of Ventricular Thrombus after Reperfused ST-Segment-Elevation Myocardial Infarction by Using Sequential Cardiac MR Imaging.

Purpose To characterize the incidence, outcomes, and predictors of left ventricular (LV) thrombus by using sequential cardiac magnetic resonance (MR) imaging after ST-segment-elevation myocardial infarction (STEMI). Materials and Methods Written informed consent was obtained from all patients, and the study protocol was approved by the committee on human research. In a cohort of 772 patients with STEMI, 392 (mean age, 58 years; range, 24-89 years) were retrospectively selected who were studied with cardiac MR imaging at 1 week and 6 months. Cardiac MR imaging guided the initiation and withdrawal of anticoagulants. Patients with LV thrombus at 6 months were restudied at 1 year. For predicting the occurrence of LV thrombus, a multiple regression model was applied. Results LV thrombus was detected in 27 of 392 patients (7%): 18 (5%) at 1 week and nine (2%) at 6 months. LV thrombus resolved in 22 of 25 patients (88%) restudied within the first year. During a mean follow-up of 181 weeks ± 168, patients with LV thrombus displayed a very low rate of stroke (0%), peripheral embolism (0%), and severe hemorrhage (n = 1, 3.7%). LV ejection fraction (LVEF) less than 50% (P < .001) and anterior infarction (P = .008) independently helped predict LV thrombus. The incidence of LV thrombus was as follows: (a) nonanterior infarction, LVEF 50% or greater (one of 135, 1%); (b) nonanterior infarction, LVEF less than 50% (one of 50, 2%); (c) anterior infarction, LVEF 50% or greater (two of 92, 2%); and (d) anterior infarction, LVEF less than 50% (23 of 115, 20%) (P < .001 for the trend). Conclusion Cardiac MR imaging contributes information for the diagnosis and therapy of LV thrombus after STEMI. Patients with simultaneous anterior infarction and LVEF less than 50% are at highest risk. © RSNA, 2017 Online supplemental material is available for this article.

Left ventricular ejection fraction recovery in patients with heart failure treated with intravenous iron: a pilot study.

AIMS: In patients with heart failure with reduced ejection fraction (HFrEF) and iron deficiency, treatment with intravenous iron has shown a clinical improvement regardless of anaemic status. Cardiac magnetic resonance (CMR) T2* sequence has shown a potential utility for evaluating myocardial iron deficiency. We aimed to evaluate whether T2* sequence significantly changes after ferric carboximaltose (FCM) administration, and if such changes correlate with changes in left ventricle ejection fraction (LVEF). METHODS AND RESULTS: In this pilot study, we included eight patients with chronic symptomatic (New York Heart Association II-III) HFrEF and iron deficiency. A CMR, including T2* analysis, was performed before and at a median of 43 days (interquartile range = 35-48) after intravenous FCM administration. Pearson or Spearman correlation coefficient (r) was used for bivariate contrast as appropriate. A partial correlation analysis was performed between ΔLVEF and ΔT2* while controlling for anaemia status at baseline. Anaemia was present in half of patients. After FCM administration, T2* decreased from a median of 39.5 (35.9-48) to 32 ms (32-34.5), P = 0.012. Simultaneously, a borderline increase in median of LVEF [40% (36-44.5) to 48.5% (38.5-53), P = 0.091] was registered. In a bivariate correlational analysis, ΔT2* was highly correlated with ΔLVEF (r = -0.747, P = 0.033). After controlling for anaemia at baseline, the association between ΔT2* and ΔLVEF persisted [r(partial): -0.865, R2(partial): 0.748, P = 0.012]. A median regression analysis backed-up these findings. CONCLUSIONS: In a small sample of patients with HFrEF and iron deficiency, myocardial iron repletion assessed by CMR was associated to left ventricular remodelling. Further studies are warranted.

Symptomatic Partial Congenital Absence of the Pericardium Revealed Using Cardiac Magnetic Resonance.

Congenital absence of the pericardium is a very uncommon finding, and its diagnosis poses a challenge because it is rarely suspected in daily clinical practice. Although in most cases it has a benign course, this congenital defect should be identified because of the associated risk of sudden death. We present a symptomatic case of partial congenital absence of the left pericardium suspected as the result of an abnormal response to exercise stress testing, and confirmed using cardiac magnetic resonance imaging. We review the current diagnostic tools and therapeutic indications of this rare anomaly.

White blood cell subtypes after STEMI: temporal evolution, association with cardiovascular magnetic resonance--derived infarct size and impact on outcome.

The evolution of white blood cells after ST elevation myocardial infarction (STEMI) and their association with infarct size and major adverse cardiac events (MACE) remains unclear. Two hundred eleven patients underwent CMR after STEMI. Infarct mass (grams) was determined. Neutrophil, lymphocyte, and monocyte counts (×1,000 cells/ml) were measured upon arrival and at 12, 24, 48, 72, and 96 h. Patients with large infarctions (3rd tertile ≥ 28.5 g vs. 1st and 2nd tertiles < 28.5 g) showed a larger neutrophil count at 12 h (14.8 ± 4.8 vs. 11.4 ± 3.3, p < 0.0001) and an increased monocyte count (maximum at 24 h (0.65[0.50-0.91] vs. 0.55[0.42-0.71], p = 0.004)) but no difference in lymphocyte count. Neutrophil count at 12 h independently predicted large infarctions (OR 1.14, 95%CI [1.04-1.26], p = 0.008). During follow-up (median 504 days), 25 MACE occurred. Neutrophil count at 96 h independently predicted MACE (HR 1.2, 95%CI [1.1-1.4], p = 0.003). Large infarctions show a marked neutrophil peak and an increasing monocyte count. Neutrophil count independently predicts large infarctions and MACE.

La suma de la elevación del segmento ST predice mejor la obstrucción microvascular en pacientes tratados con éxito con una intervención coronaria percutánea primaria. Un estudio de resonancia magnética cardiovascular / The sum of ST-segment elevation is the best predictor of microvascular obstruction in patients treated successfully by primary percutaneous coronary intervention. Cardiovascular magnetic resonance study

Introducción y objetivos. La utilidad de la resolución del segmento ST (RST) para la predicción de la reperfusión epicárdica está bien establecida. La asociación de los cambios del segmento ST con la obstrucción microvascular (OMV) observada en la resonancia magnética cardiovascular (RMC) tras una intervención coronaria percutánea primaria (ICPp) en el infarto de miocardio con elevación del ST (IMEST) no se ha aclarado todavía. Métodos. Estudiamos a 85 pacientes consecutivos ingresados por un primer IMEST y tratados con una ICPp que tenían una arteria relacionada con el infarto permeable. Se registró un ECG al ingreso, tras 90 min y tras 6, 24, 48 y 96 h de la ICPp. Se calculó la RST y la suma de la elevación del ST (sumEST) en todas las derivaciones. Resultados. La RMC reveló una OMV en 37 pacientes. En los infartos con OMV, el valor de la sumEST antes y después de la revascularización fue mayor que en los infartos sin OMV (p <= 0,001 en todos los casos). En cambio, no hubo diferencias significativas en la cantidad de RST entre los infartos con y sin OMV a los 90 min de la revascularización (p = 0,1), sino sólo a partir de las 6 h (p < 0,05 en todos los casos). El área bajo la curva de características operativas del receptor para la detección de la OMV fue mayor para la sumEST que para la RST (p < 0,05 en todas las determinaciones). En el análisis multivariable, ajustado respecto a las características clínicas, angiográficas y electrocardiográficas, una sumEST > 3 mm a los 90 min de la ICPp, pero no una RST >= 70%, predijo de manera independiente la OMV observada en la RMC (odds ratio = 3,1; intervalo de confianza del 95%, 1,2-8,4; p = 0,02). Conclusiones. La OMV se asoció a un valor significativamente superior de la sumEST en todos los momentos de valoración tras la revascularización. La diferencia en la cantidad de RST entre los infartos con OMV y sin OMV sólo fue significativa a partir de las 6 h tras la revascularización. La OMV se predijo mejor con una sumEST > 3 mm a los 90 min de la ICPp (AU)

Introduction and objectives. The usefulness of STsegment elevation resolution (STR) for predicting epicardial reperfusion is well established. However, it is still not clear how ST-segment changes are related to microvascular obstruction (MVO) observed by cardiovascular magnetic resonance (CMR) after primary percutaneous coronary intervention (pPCI) for ST-segment elevation myocardial infarction (STEMI). Methods. The study involved 85 consecutive patients admitted for a first STEMI and treated by pPCI who had a patent infarct-related artery. An ECG was recorded on admission and 90 min and 6, 24, 48 and 96 h after pPCI. Thereafter, STR and the sum of ST-segment elevation (sumSTE) in all leads were determined. Results. Overall, CMR revealed MVO in 37 patients. In infarcts with MVO, sumSTE was greater both before and after revascularization than in infarcts without MVO (P<=.001 at all times). In contrast, there was no significant difference in the magnitude of STR between infarcts with and without MVO 90 min after revascularization (P=.1), though there was after 6 h (P<.05 at all times). The area under the receiver operating characteristic curve for detecting MVO was greater for sumSTE than STR (P<.05 for all measurements). On multivariate analysis, after adjusting for clinical, angiographic and ECG characteristics, a sumSTE >3 mm 90 min after pPCI was an independent predictor of MVO on CMR, while an STR >=70% was not (odds ratio=3.1; 95% confidence interval, 1.2-8.4; P=.02). Conclusions. MVO was associated with a significantly increased sumSTE at all times after revascularization. The difference in the magnitude of STR between infarcts with and without MVO was significant only >6 h after revascularization. The best predictor of MVO was a sumSTE >3 mm 90 min after pPCI. Key words: Cardiovascular magnetic resonance. Microvascular obstruction. ST-segment resolution. Sum of ST-segment elevation. ST-segment elevation myocardial infarction (AU)

The sum of ST-segment elevation is the best predictor of microvascular obstruction in patients treated successfully by primary percutaneous coronary intervention. Cardiovascular magnetic resonance study.

INTRODUCTION AND OBJECTIVES: The usefulness of ST-segment elevation resolution (STR) for predicting epicardial reperfusion is well established. However, it is still not clear how ST-segment changes are related to microvascular obstruction (MVO) observed by cardiovascular magnetic resonance (CMR) after primary percutaneous coronary intervention (pPCI) for ST-segment elevation myocardial infarction (STEMI). METHODS: The study involved 85 consecutive patients admitted for a first STEMI and treated by pPCI who had a patent infarct-related artery. An ECG was recorded on admission and 90 min and 6, 24, 48 and 96 h after pPCI. Thereafter, STR and the sum of ST-segment elevation (sumSTE) in all leads were determined. RESULTS: Overall, CMR revealed MVO in 37 patients. In infarcts with MVO, sumSTE was greater both before and after revascularization than in infarcts without MVO (P≤.001 at all times). In contrast, there was no significant difference in the magnitude of STR between infarcts with and without MVO 90 min after revascularization (P=.1), though there was after 6 h (P< .05 at all times). The area under the receiver operating characteristic curve for detecting MVO was greater for sumSTE than STR (P< .05 for all measurements). On multivariate analysis, after adjusting for clinical, angiographic and ECG characteristics, a sumSTE >3 mm 90 min after pPCI was an independent predictor of MVO on CMR, while an STR ≥70% was not (odds ratio=3.1; 95% confidence interval, 1.2-8.4; P=.02). CONCLUSIONS: MVO was associated with a significantly increased sumSTE at all times after revascularization. The difference in the magnitude of STR between infarcts with and without MVO was significant only >6 h after revascularization. The best predictor of MVO was a sumSTE >3 mm 90 min after pPCI.

Resonancia cardiaca: hacia una generalización de su aplicación clínica / No disponible

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