Detection Of Ischemia In Patients Research Articles

Stress perfusion CMR – a report of an initial Romanian experience

Abstract Objectives To provide preliminary data on practice of stress perfusion cardiovascular magnetic resonance (CMR) in a single center in Romania. Methods We retrospectively reviewed the clinical files and CMR reports of patients who underwent stress perfusion CMR in our institution between January 2018 and December 2020. Results A total of 1036 patients underwent CMR examinations during this period in our institution. Of these, 120 patients had stress perfusion CMR. The most common indication was the assessment of myocardial ischaemia in patients with established coronary artery disease (CAD) (77 patients, 64.16%), with either a history of myocardial infarction or previous coronary revascularization, or with intermediate lesions on invasive coronary angiography (ICA). The other indications consisted in detection of ischaemia in patients with suspected CAD (36 patients, 30%), characterization of the substrate of ventricular arrhythmia (5 patients, 4.16%) and assessment of the etiology of dilated cardiomyopathy (DCM) (4 patients, 3.33%). All patients had vasodilator stress with adenosine and an adequate stress response was obtained in 113 patients (94.16%). There were 21 patients (18.58%) with an abnormal stress test and patients with intermediate lesions on ICA had the highest prevalence of positive reports (24.32%). Sixty-three patients had myocardial fibrosis (52.5%): 49 patients (40.83%) had subendocardial (ischaemic) scars, while 14 patients (11.66%) had non-ischaemic scars. There were no serious adverse events related to the procedure. Conclusions This is the first report in Romania on the use of stress perfusion CMR in clinical practice. We report our experience on stress efficiency, acquisition protocol, artifacts, prevalence of positive tests and safety. Most stress CMRs were requested in patients with established CAD.

Computed Tomography Myocardial Perfusion Imaging With Transesophageal Atrial Pacing Stress Test in Patients With Borderline Stenoses in the Coronary Arteries: a Comparison With Fractional Flow Reserve.

Aim To evaluate the diagnostic accuracy of cardiac perfusion computed tomography (PCT) with transesophageal electrocardiostimulation (TE ECS) for detection of ischemia in patients with borderline coronary stenosis (50-75 %) compared to measurements of fractional flow reserve (FFR).Material and methods The study included 25 patients with borderline (50-75 %) coronary stenosis as per data of computed tomography angiography (CTA) or coronary angiography (CAG). Later the patients underwent invasive measurement of FFR and cardiac PCT on a 320-row detector tomograph in combination with the TE ECS stress test. FFR values <0.8 indicated the hemodynamic significance of stenosis. Myocardial perfusion was evaluated visually based on consensus of two experts.Results All patients completed the study protocol. Cardiac pacing duration was 6 min for all patients. Four patients required intravenous administration of atropine sulphate. PCT with TE ECS detected significant for FFR stenoses with sensitivity, specificity, and predictive value of a positive result and predictive value for a negative result of 47, 90, 87, and 53 %, respectively.Conclusion PCT with TE ECS in combination with CTA can be considered as an informative method for simultaneous evaluation of the condition of coronary arteries and detection of myocardial ischemia. This method is particularly relevant for assessing the hemodynamic significance of borderline coronary stenoses.

Invasive versus noninvasive assessment of functional significance of intermediate coronary artery lesions

BackgroundMyocardial perfusion imaging (MPI) is noninvasive test used for evaluation of functional significance of borderline coronary artery lesions. Moreover, instantaneous wave-free ratio (IFR) is a well-validated invasive method used for the same purpose.ObjectivesTo compare the results of MPI and IFR in detection of ischemia in patients with single intermediate coronary artery lesion.Patients and methodsA total of 60 patients with single intermediate coronary artery stenosis, visually judged as angiographic stenosis more than or equal to 50% and less than 70% during coronary angiography, were included. After coronary angiography, all patients were subjected to MPI and IFR at National Heart Institute between February 2018 and February 2020. IFR value less than or equal to 0.89 was considered significant, indicating functionally significant lesion, and IFR value more than or equal to 0.89 was considered insignificant, indicating functionally insignificant lesion. MPI results were considered positive when the defect size more than or equal to 10% in the territory of the affected vessel.ResultsAmong 60 patients, 37 (61.7%) patients showed significant IFR value and 23 (38.3%) patients showed insignificant IFR value. Of 37 patients with significant IFR value, 30 (81.1%) patients showed positive MPI results and seven (18.9%) patients showed negative MPI results. Of 23 patients with insignificant IFR value, 19 (82.6%) patients showed negative MPI results, and four (17.4%) patients showed positive MPI results. So, there was good (kappa = 0.62), significant (P = 0.001) agreement between the MPI and IFR results. The sensitivity was 81.1%, the specificity was 82.6%, positive predictive value was 88.2%, the negative predictive value was 73.1%, and the accuracy was 81.7%.ConclusionsMPI may be a valid alternative, noninvasive, less-expensive test than IFR for evaluation of functional significance of intermediate coronary artery lesions.

Speckle-tracking during dipyridamole stress echocardiography in the detection of myocardial ischemia in patients with suspected coronary artery disease

Abstract Background The aim of this study was to investigate the incremental value of global longitudinal strain (GLS), postsystolic strain index (PSI) and prestretch (PSE) by automated function imaging with respect to wall motion (WM) and coronary flow reserve (CFR) for the diagnosis of significant coronary artery disease (CAD) during dipyridamole stress echocardiography. Methods We retrospectibely enrolled 227 patients with known or suspected CAD, approaching our echo lab to perform a DSE; all patient underwent coronary angiography within 1 month for clinical reasons. Obstructive CAD was defined as the evidence of >70% stenosis during coronary angiogram. Obstructive CAD was detected in 143 (63%) patients, while 84 (37%) had no significant CAD. Global longitudinal strain, PSI and PSE were measured at rest and peak of the stress (after 6 minutes of 0,84mg/kg of dipyridamole infusion). Results Patient with CAD showed a significantly lower GLS at rest (−16.9±4.2 vs −18.6±3.4; p<0.01) and peak (14.9±3.8 vs −21.50±3.3; p<0.01) Figure A; the behavior of GLS was opposite, in patient with CAD showed an increase while in patient without CAD a significant decrease after dipyridamole infusion. There was also a significant difference between groups for Delta PSI (PSIpeak − PSIrest) and Delta PSE (PSEpeak − PSErest), respectively 126±145 vs −40±97, (p<0.01) and 108±163 vs −41±106 (p<0.01) Figure C. ROC analyses produced a statistically valid model: Average GLS at peak (p 0.001; AUC=0.906, cut-off value −18%, sensitivity 83% and specificity 82%); on the basis of these results, we compared WM and myocardial deformation analysis and GLS was superior to CFR LAD, Delta EF, Delta ESV and Delta WMI (Figure B). Conclusions GLS, PSE and PSI show an opposite response to dipyridamole, in patients with CAD in patient without CAD and show much higher sensitivity and specificity compared to the conventional parameters like WMI, EF and CFR in detecting CAD Funding Acknowledgement Type of funding source: None

P1504Impact of myocardial ischemia induced by exercise stress echocardiography on the QT dispersion in patients with the left bundle branch block

Abstract Background/Introduction ECG has always provided very useful information that can be used to diagnosis, treatment and prevention of cardiovascular events, but ECG changes is not useful to the detection of myocardial ischemia in patients with left bundle branch block (LBBB). QT dispersion (QTd) is a measure of inhomogeneous repolarization of myocardium. Abnormally high QTd has been correlated with risk of cardiac death in coronary patients. Purpose The aim of this study was to establish the impact of myocardial ischemia induced by exercise stress echocardiography on the QT dispersion in patients with the left bundle branch block. Methods The study involved 123 patients with LBBB, average age 52.7 years. In all subjects clinical examination, standard ECG and exercise stress echocardiography, were performed. The criterion for myocardial ischemia was the appearance of transient segmental wall motion abnormality. The first ECG was done before the exercise stress echocardiography and the second one was done immediately after exercise, with calculation of corrected QT dispersion (QTdc). Results During exercise stress echocardiography, in 45 (36.6%) subjects wall motion abnormality occurred (group with myocardial ischemia: MI), and 78 (63.4%) subjects were without ischemia (group without myocardial ischemia: NMI). Before starting the exercise stress echocardiography, MI group patients had significantly higher values of QTdc (61.2±17.6 vs 43.6±15.4 ms; p<0.001) in comparison to NMI group patients. During the exercise stress echocardiography, the QTdc significantly increased in MI group from 61.2±17.6 to 87.4±20.3 ms (p<0.001). In the NMI group there were no significant changes in the values QTdc during exercise stress echocardiography (from 43.6±15.4 to 46.5±19.8 ms (p - NS). Conclusions Significant increase of QT dispersion is associated with the occurrence of myocardial ischemia during exercise stress echocardiography in patients with LBBB. This new diagnostic approach, of using QT dispersion, significantly improves the clinical usefulness of exercise stress echocardiography in detecting myocardial ischemia in patients with LBBB.

Serial electrocardiography to detect newly emerging or aggravating cardiac pathology: a deep-learning approach

BackgroundSerial electrocardiography aims to contribute to electrocardiogram (ECG) diagnosis by comparing the ECG under consideration with a previously made ECG in the same individual. Here, we present a novel algorithm to construct dedicated deep-learning neural networks (NNs) that are specialized in detecting newly emerging or aggravating existing cardiac pathology in serial ECGs.MethodsWe developed a novel deep-learning method for serial ECG analysis and tested its performance in detection of heart failure in post-infarction patients, and in the detection of ischemia in patients who underwent elective percutaneous coronary intervention. Core of the method is the repeated structuring and learning procedure that, when fed with 13 serial ECG difference features (intra-individual differences in: QRS duration; QT interval; QRS maximum; T-wave maximum; QRS integral; T-wave integral; QRS complexity; T-wave complexity; ventricular gradient; QRS-T spatial angle; heart rate; J-point amplitude; and T-wave symmetry), dynamically creates a NN of at most three hidden layers. An optimization process reduces the possibility of obtaining an inefficient NN due to adverse initialization.ResultsApplication of our method to the two clinical ECG databases yielded 3-layer NN architectures, both showing high testing performances (areas under the receiver operating curves were 84% and 83%, respectively).ConclusionsOur method was successful in two different clinical serial ECG applications. Further studies will investigate if other problem-specific NNs can successfully be constructed, and even if it will be possible to construct a universal NN to detect any pathologic ECG change.

Exercise Echocardiography in Children

Exercise echocardiography has been widely used in adult cardiology, and is mainly used for assessing regional myocardial function in patients with known or suspected coronary artery disease. In addition, it is also useful in the evaluation of the haemodynamic significance of valve disease, such as aortic stenosis and mitral regurgitation. In children, exercise echocardiography has found its place in the detection of ischaemia in patients with coronary artery abnormalities such as Kawasaki disease, and abnormal origin of coronary arteries. Other indications include assessment of haemodynamic and myocardial response in patients with different types of congenital heart disease, the early detection of myocardial dysfunction in specific populations such as patients after chemotherapy exposure. The incorporation of tissue Doppler and strain imaging with exercise echocardiography has allowed a more quantitative analysis of regional and global systolic and diastolic function.

Magnetocardiography for the diagnosis of non-obstructive coronary artery disease1.

Ischemic heart disease (IHD) remains a major public health burden worldwide. It is estimated that one third of adults in the United States has some form of IHD, including more than 17 million with coronary artery disease (CAD) and nearly 10 million with angina pectoris [1]. Nevertheless, the detection of myocardial ischemia in patients with presumed CAD remains a challenge in contemporary practice.

The role of biomarkers in the diagnosis and risk stratification of acute coronary syndrome.

Coronary artery disease is a growing concern. Although traditional biomarkers, such as troponins and creatine kinase, play a central role in the diagnosis, risk stratification and management of coronary artery disease, they are unable to detect myocardial ischemia in the absence of necrosis. Therefore, early detection of ischemia in patients presenting with acute coronary syndrome still remains a burning question. High-sensitivity troponin is evolving as a reliable biomarker in this regard and has been absorbed into clinical practice. Biomarkers are currently the focus of immense interest as it not only helps with diagnosis and management but also helps to understand the pathophysiology of the disease process. In addition, analysis using a multimarker strategy has also proven to be a very useful tool in risk stratification. This review will focus on the biomarkers and its application in the diagnosis and risk stratification of acute coronary syndrome.

Effects of caffeine on the detection of ischemia in patients undergoing adenosine stress cardiovascular magnetic resonance imaging

BackgroundAdenosine stress cardiovascular magnetic resonance (CMR) can detect significant coronary artery stenoses with high diagnostic accuracy. Caffeine is a nonselective competitive inhibitor of adenosine2A-receptors, which might hamper the vasodilator effect of adenosine stress, potentially yielding false-negative results. Much controversy exists about the influence of caffeine on adenosine myocardial perfusion imaging. Our study sought to investigate the effects of caffeine on ischemia detection in patients with suspected or known coronary artery disease (CAD) undergoing adenosine stress CMR.MethodsThirty patients with evidence of myocardial ischemia on caffeine-naïve adenosine stress CMR were prospectively enrolled and underwent repeat adenosine stress CMR after intake of 200 mg caffeine. Both CMR exams were then compared for evaluation of ischemic burden.ResultsDespite intake of caffeine, no conversion of a positive to a negative stress study occurred on a per patient basis. Although we found significant lower ischemic burden in CMR exams with caffeine compared to caffeine-naïve CMR exams, absolute differences varied only slightly (1 segment based on a 16-segment model, 3 segments on a 60-segment model, and 1 ml in total ischemic myocardial volume, p < 0.001 each). Moreover, no relevant ischemia (≥2 segments in a 16-segment model) was missed by prior ingestion of caffeine.ConclusionsAlthough differences were small and no relevant myocardial ischemia had been missed, prior consumption of caffeine led to significant reduction of ischemic burden, and might lower the high diagnostic and prognostic value of adenosine stress CMR. Therefore, we suggest that patients should still refrain from caffeine prior adenosine stress CMR tests.

Stress echocardiography in paediatric cardiology.

Stress echocardiography is a well-established technique in adult cardiology and is mainly used for assessing regional myocardial function in patients with known or suspected coronary artery disease (CAD). Apart from detecting ischaemia, stress echocardiography has found its place in the assessment of the haemodynamic significance of valve disease, particularly in selected patients with aortic stenosis and mitral regurgitation. Also in the paediatric population, stress imaging is most commonly used for the detection of ischaemia in patients with CADs such as post heart transplantation, Kawasaki Disease, and abnormal origin of coronary arteries. Other paediatric indications include the haemodynamic and myocardial response in patients with different types of congenital heart disease, the early detection of myocardial dysfunction in specific populations such as patients after anthracycline exposure, and the evaluation of pulmonary artery pressures and the right ventricular functional response. Techniques have evolved over time and in different paediatric echocardiographic laboratories, exercise stress echocardiography is replacing dobutamine stress echocardiography in older children. Moreover, integrating tissue Doppler and strain technology with stress imaging allows a more quantitative analysis of regional and global systolic and diastolic function. Current clinical applications mainly include patients after transplant, suspected CAD, and hypertrophic cardiomyopathy.

Comparison of Tc-99m tetrofosmin myocardial perfusion scintigraphy and exercise F18-FDG imaging in detection of myocardial ischemia in patients with coronary artery disease

BackgroundDirect ischemia imaging with F18-FDG can potentially overcome many limitations of SPECT-MPS inherent to “cold imaging”. We compared SPECT-MPS with exercise F18-FDG PET in detection of ischemia in patients with suspected CAD. Methods45 patients with clinical suspicion of CAD without the history of myocardial infarction were prospectively included. All patients underwent Tc-99m tetrofosmin SPECT-MPS and exercise F18-FDG PET imaging within 7 days of SPECT-MPS, and both modalities were compared with coronary angiography for detecting ischemia. Results27 patients had an abnormal coronary angiography (at least one coronary artery with stenosis >50%). Exercise F18-FDG performed better than SPECT-MPS in LAD and LCX territory with comparably good performance in RCA territory. Exercise F18-FDG performed better in single-vessel disease and equally good in multi-vessel disease compared to SPECT-MPS. Performance of exercise 18F-FDG study was significantly better than SPECT-MPS (P = .0014) in the analysis of the 81 vascular territories in the 27 patients with abnormal coronary angiography. Performance of exercise F18-FDG was significantly better than SPECT-MPS in detecting ischemia in suspected CAD patients. ConclusionExercise F18-FDG imaging is a potentially useful ischemia imaging modality which offers the advantages of direct ischemia imaging in CAD patients.

The Value of β-Blockers Administration during Recovery Phase of Dobutamine Stress Echocardiography: A Review

Dobutamine stress echocardiography (DSE) is a successful technique for detection of ischemia in patients with suspected coronary artery disease (CAD). There are some data that administration of β-blocker after peak infusion of dobutamine can improve sensitivity. The goal of this manuscript is to review the current literature in regard to the mechanism and accuracy of post-dobutamine β-blocker administration for ischemia detection. In this review, we present 2 case reports followed by detailed review of the literature.

Circulation: Cardiovascular Imaging Editors’ Picks

<i>Circulation: Cardiovascular Imaging</i> Editors’ Picks

Accelerated three-dimensional free-breathing first pass cardiac perfusion at 1.5T

Background Perfusion CMR provides an important diagnostic tool for the detection of myocardial ischemia in patients with known or suspected CAD [1]. Conventionally, 2D multislice imaging with 2-4 short-axis slices is often used for evaluation of left ventricular perfusion. 3D CMR perfusion has been proposed for its superior coverage and higher SNR [2]. However, accelerated imaging is required for adequate spatio-temporal resolution. Recent studies in accelerated CMR have shown that utilizing local information in the imaging volume significantly improves reconstruction quality [3,4]. However, such highly accelerated k-t based techniques used for 3D perfusion [3] require breath-hold acquisitions, which may be difficult following physical stress or for some patients. In this study, we sought to develop a compressed-sensing (CS) based image reconstruction technique utilizing local imaging features for highly-accelerated 3D free-breathing perfusion CMR.

First-pass myocardial stress perfusion MRI using k-t BLAST at an open MR-system: initial results in comparison to FFR measurements

Background First-pass myocardial stress perfusion MR imaging (MRI) is routinely used for the detection of myocardial ischemia in patients with suspected or known coronary artery disease (CAD). Up to now, cardiac MRI stress testing had to be performed in a closed bore environment. To allow for MR stress perfusion in claustrophobic patients and to improve monitoring during stress examination and in critically ill patients an open MR platform seems desirable. Recently, an open 1.0T MRsystem with high gradient performance has been introduced, which may allow for first-pass myocardial stress perfusion in combination with fast data acquisition techniques such as k-t BLAST. Therefore, the aim of our study was to evaluate 1) feasibility of adenosine stress perfusion (ASP) MRI using k-t

Analysis of regional wall motion during contrast-enhanced dobutamine stress echocardiography: effect of contrast imaging settings

Myocardial contrast perfusion echocardiography (MCE) allows simultaneous assessment of perfusion and function. However, low frame rate during MCE may reduce the viewer's ability to discern contractile dysfunction. This study sought to compare MCE and left ventricular opacification (LVO) settings with regard to wall motion abnormalities (WMA) at rest and during dobutamine stress echocardiography (DSE). In 50 patients scheduled for coronary angiography and with poor baseline image quality, MCE and LVO were performed during DSE. Regional wall motion was assessed and inter-observer agreement was determined for each imaging modality. The endocardial border score index was similar for both modalities. The wall motion score index (WMSCI) at peak stress using MCE was well correlated with WMSCI obtained with LVO (r(2) = 0.9, P < 0.001). However, WMSCI at peak stress was underestimated by MCE (1.66 +/- 0.58 with DSE-LVO vs. 1.535 +/- 0.50 with DSE-MCE; P < 0.001). Inter-observer agreement on the presence of WMA was 0.65 for MCE and 0.67 for LVO at peak stress. Myocardial contrast perfusion echocardiography provides equal endocardial border delineation compared with LVO modality. Although the inter-observer agreement is slightly higher with LVO compared with MCE, it is not significantly different with MCE at peak stress. Despite the similar improvement in endocardial border delineation, LVO settings allow the detection of more WMA than MCE at peak stress, leading to a significantly higher accuracy for the detection of ischaemia in patients suspected of coronary artery disease when only wall motion is taken into account.

Electrocardiogram detection of acute global cardiac ischemia in patients presenting with acute chest pain

Electrocardiogram detection of acute global cardiac ischemia in patients presenting with acute chest pain

Detection of Myocardial Ischemia in Patients with Blunted Hemodynamic Response to Adenosine Stress

Detection of Myocardial Ischemia in Patients with Blunted Hemodynamic Response to Adenosine Stress

Predictive value of rest magnetocardiography in patients with stable angina

Abstract. Magnetocardiographic mapping (MCG) is increasingly used for non-invasive early detection of ischemia in patients with acute chest pain. This study was aimed to evaluate the predictive value of MCG, for the diagnosis of ischemia in patients with coronary artery disease (CAD) and stable angina (StA). 51 pts (age 63 ± 10.7 years) with CAD (all chest pain free at the time of MCG) and 52 healthy volunteers were studied at rest with an unshielded 36-channel MCG system (sensitivity: 20 fT/√Hz, above 1 Hz). 42 pts underwent coronary angiography (CAng) (21 after MCG scan). 39 pts had stress SPECT; 32 had both CAng and SPECT. Analysis of ventricular repolarization (VR) was performed utilizing different methods for interactive and automated analysis of T-wave dynamics and of the effective magnetic vector (EMV) parameters. For all pts, best sensitivity, specificity, PPV, NPV and predictive accuracy of the MCG for the detection of ischemia were 56%, 96%, 94%, 69% and 78%, respectively (with EMV). If pts with previous myocardial infarction (MI) were excluded, best sensitivity, specificity, PPV, NPV and predictive accuracy of the MCG for the detection of ischemia were 83%, 96%, 94%, 89% and 91%, respectively (detected with EMV). Comparative values calculated from ECG were 38%, 100%, 100%, 80% and 82%, respectively. As compared with previous results in pts with ACS, the T-wave analysis seems to be less sensitive in pts with chronic CAD and previous MI. Further work is needed to better define MCG parameters to be used for the diagnosis of myocardial ischemia in pts with CAD and to differentiate VR abnormalities due to coexistent ventricular hypertrophy, previous MI, or other cardiomyopathy.