Enhancement Cardiac Magnetic Resonance Imaging Research Articles

Single-beat mapping during programmed ventricular stimulation identifies infarct-related ventricular tachycardia isthmus sites

Abstract Introduction Complete characterization of reentrant ventricular tachycardia (VT) circuits using classical electrophysiological criteria and high-density mapping during VT is complex. Often, VT episodes cannot be fully characterized because of hemodynamic instability during the mapping procedure. This common limitation has motivated the implementation of mapping strategies during sinus rhythm or ventricular pacing aiming to identify scar regions associated with VT isthmuses or potential arrhythmogenicity. However, these strategies still require time-consuming catheter-based mapping. Purpose We aimed to develop and validate a single-beat mapping strategy during programmed ventricular stimulation (PVS) to identify scar regions associated with VT isthmus sites. We hypothesize that protected VT isthmuses within scar regions are characterized by larger activation time dispersion than surrounding scar areas not related to critical isthmus sites. Methods Experimental study including 16 pigs with established myocardial infarction (MI) in the anterior wall. Ten-to-twelve weeks after MI, pigs underwent left ventricular characterization using 3D late-gadolinium enhancement cardiac magnetic resonance imaging, and further invasive electroanatomical mapping to obtain high-density sequential activation maps during ventricular pacing and VT. High-density maps were compared with single-beat maps using a 64-pole basket catheter positioned in the left ventricle. After VT induction, high-density activation maps in well-tolerated VT episodes were used to identify VT isthmus sites. Simultaneous activation data from the 64-pole basket catheter were also obtained during PVS and VT. Off-line analysis was performed to: (i) validate single-beat activation maps during the baseline drive pacing cycle length (S1), and (ii) identify basket-catheter electrodes with the larger local activation time-dispersion score (LAT-DS) during PVS including up to 4 coupled extrastimuli (S2, S3, S4, S5) (Figure 1). LAT-DS was defined as the normalized product of the LAT of each electrode and the activation dispersion among its neighboring electrodes. Results Basket-catheter based single-beat activation maps during S1 pacing showed high correlation values with high-density sequential activation maps (N=16. R²=0.91). In 7 pigs, the VT isthmus site was fully characterized using high-density activation maps. During any of the coupled extrastimuli of the PVS protocol, basket catheter electrodes colocalizing with documented VT isthmus sites on high-density maps showed higher LAT-DS values compared to surrounding electrodes located on scar or healthy regions. Conversely, LAT values alone could not differentiate scar regions relevant for VT maintenance during PVS protocol (Figure 2). Conclusions Sixty-four pole single-beat activation maps during PVS identify left ventricular scar areas with higher than surrounding LAT-DS values that are associated with VT isthmus sites.Figure 1.Experimental modelFigure 2.A-Example. B-C-Full results

The correlation between left atrium voltage mapping and 3D late gadolinium enhancement cardiac magnetic resonance imaging findings in patients with known atrial fibrillation

Abstract Introduction The non-invasive cardiac magnetic resonance imaging-based late gadolinium enhancement (LGE-CMR) of the left atrium (LA) fibrosis distribution and degree can be utilized for preprocedural planning and real-time guidance of AF ablation. There is an ongoing discussion with somewhat conflicting results regarding the accuracy of LGE-CMR of the LA as compared with the invasive electroanatomical mapping (EAM). Earlier data mainly encompassed post-ablation patients with an EAM involving a relatively small number of acquired points. Aim To evaluate the accuracy of LGE-CMR-based LA fibrosis using the ADAS 3D LA software among ablation-naive AF patients as compared with EAM using the CARTO-3 navigation system. Methods Patients with non-permanent AF, naive to previous ablation/cardiac surgery, who underwent CARTO-based AF ablation with preceding LGE-CMR scan were selected for the study. The 3D substrate atrial maps were generated based on the LGE-CMR (CMR-fib) using the ADAS 3D LA software and the CARTO EAM (EAM-fib). A fibrosis threshold of 1.2-1.32 was established for the CMR-fib using the Image Intensity Ratio whereas a threshold of 0.2-0.5mV was applied for the EAM-fib. The two 3D-maps were assessed for fibrosis using anatomically synchronized quantitative point by point comparison. The EAM was set as the gold standard. Results The study included 26,777 points acquired from 17 patients (aged 65.8±7.92 yrs with 6 females and 10 paroxysmal AF cases). CMR-fib showed 22.0% of LGE, while the EAM-fib demonstrated 48.8% of low voltage areas. The CMR-fib vs. EAM-fib point by point comparison concluded with an agreement of 73.1% and interrater reliability of 0.45 (p<0.001). The sensitivity and specificity were 45.0% and 99.9%, respectively, while the PPV and NPV were 99.8% and 65.6%, respectively. The Area Under the Curve (AUC) was calculated as 72.4. Increase of the EAM-fib threshold for scar (to 0.5-1.5mV) led to a further decrease in the assessment diagnostic performance and the interrater reliability. The lowest agreement was tested in the LA roof segments and the higher in the inferoseptal and posterior walls. Conclusion The LGE-CMR underestimates the presence of scar as presented by the EAM, however, those detected are mostly accurate. The low sensitivity that was demonstrated between the two methods may be attributed to the lower spatial resolution of the CMR as well as the superficial subendocardial layer mapped by EAM as compared with the averaged transmural mapping of the CMR-fib. A follow-up larger-scale study is required to assess the accuracy of LGE-CMR-based assessment of fibrosis, considering various wall thicknesses and establishing the scar threshold on the ADAS software, particularly for ablation-naive patients.

Novel systematic processing of cardiac magnetic resonance imaging identifies target regions associated with infarct-related ventricular tachycardia

Abstract Introduction In the clinic, complete characterization of reentrant ventricular tachycardia (VT) circuits using classical electrophysiological criteria and state-of-the-art high density mapping during VT is complex, and often cannot be completed because of hemodynamic instability. This common limitation has motivated the implementation of mapping strategies during sinus rhythm or ventricular pacing aiming to identify scar regions associated with VT isthmuses or potential arrhythmogenicity. Complementary imaging-based strategies including advanced analyses of scar tissue characteristics have been also proposed for procedure planning and identification of potential arrhythmogenic regions. However, the most recent expert consensus report on catheter ablation of ventricular arrhythmia highlights the lack of agreement on the preferable signal intensity (SI) cut-off values for assessment of tissue heterogeneity and scar areas on late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) images. The latter makes LGE-CMR imaging processing highly operator-dependent and potentially sensitive to selection bias. Purpose We aimed at developing and validating a systematic processing approach on LGE-CMR images to identify potential VT corridors that may include protected isthmuses associated with VT maintenance. Methods Translational study including 18 pigs with established myocardial infarction and inducible VT undergoing in vivo characterization of the anatomical and functional myocardial substrate associated with VT maintenance. Clinical validation was conducted in a multicenter series of 33 patients with ischemic cardiomyopathy undergoing VT ablation. Three-dimensional CMR-LGE images were processed using systematic scanning of 15 signal intensity cut-off ranges to obtain surface visualization of all potential VT corridors. Analysis and comparisons of imaging and electrophysiological data were performed in individuals with full electrophysiological characterization of the isthmus sites of at least one VT morphology. Results In both the experimental pig model and patients undergoing VT ablation, all the electrophysiologically-defined isthmus sites (n=11 and n=19, respectively) showed overlapping regions with CMR-based potential VT corridors. Such imaging-based VT corridors were less specific than electrophysiologically-guided ablation lesions at functionally relevant isthmus sites (Figure). However, in patients, decreasing from 15 to 7 the number of signal intensity cut-off ranges for systematic imaging processing significantly reduced the area of imaging-based potential VT corridors, without diminishing the capability to detect functionally relevant VT isthmus sites. Conclusions Systematic processing of 3D LGE-CMR images provides unbiased identification of imaging based potential VT corridors that contain functionally relevant protected isthmus sites.

An optimized multisource acquisition and registration workflow for imaging guided ventricular tachycardia ablation

Abstract Background Catheter ablation is a cornerstone treatment for scar-related ventricular arrhythmias arising in patients affected by structural heart disease. Imaging integration with electroanatomical mapping (EAM) suites for ventricular tachycardia (VT) ablation procedural guidance is an established step for advanced substrate characterization and treatment. Purpose To compare and validate different approaches for intraprocedural multisource imaging registration and integration with EAM suites for VT ablation guidance. Methods Thirty consecutive patients prospectively enrolled in the ongoing VOYAGE clinical trial for imaging guided/aided VT ablation at our center were retrospectively analyzed. Multidetector computed tomography (MDCT) and late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) imaging was performed before procedure. MDCT and LGE-CMR images were both acquired during end-expiratory breath hold. Same cardiac cycle phase images were used. Wide band LGE-CMR was acquired in case of a cardiac implantable electronic device was present to reduce artifacts. Images were imported in ADAS3D software. MDCT and CMR images were manually registered using established anatomical landmarks (left ventricle outflow tract, left ventricle apex, papillary muscles, left and right ventricle junction), were then respectively processed for aortic/ventricular anatomical reconstruction and myocardial characterization and then imported in CARTO3 electroanatomical mapping suite for procedural guidance. Registration between EAM and imaging was either performed with ascending aorta fast anatomical mapping (FAM) and 3D landmark alignment with aortic MDCT or via intracardiac echocardiography (ICE) left ventricle (LV) chamber segmentation and 3D landmark alignment with ventricular MDCT. ICE segmentation was also obtained for every case regardless of aortic FAM. Surface match between ICE and MDCT LV chamber reconstructions was calculated for method comparison. Results All 30 patients had an ICE segmentation of the LV, with a mean of 15,66±4,89 contours. Aortic FAM was obtained and used for aortic MDCT registration in 10 subjects. LV ICE was instead used for imaging alignment in 20 subjects. When compared to aortic FAM, LV ICE to LV MDCT alignment achieved lower average surface distance (3,86±1,41 mm vs 8,884±6,77 mm; p<0,001), lower minimum surface distance (0,002±0,03 vs 0,07±0,06; p= 0,001) and lower maximum surface distance (14,16±4,37 vs 22,93±11,10; p<0,001). Conclusion An optimized workflow consisting of ICE LV chamber segmentation was superior in terms of 3D surface distance to aortic FAM reconstruction to obtain reliable multisource imaging registration for MDCT/CMR guided/aided VT ablation.

Incremental value of myocardial global longitudinal strain in predicting major adverse cardiac events among patients with hypertrophic cardiomyopathy.

Endocardial global longitudinal strain (endo-GLS) measured with echocardiography (echo) has been demonstrated to be associated with myocardial fibrosis (MF) and is a prognostic predictor in patients with hypertrophic cardiomyopathy (HCM). Late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) imaging showed that MF is primarily located in the myocardial layer of the extremely hypertrophic septal or ventricular wall. We hypothesized that GLS of the myocardial layer (myo-GLS) is more strongly correlated with the extent of LGE (%LGE) and is a more powerful prognostic factor than endo-GLS. A total of 177 inpatients (54.0 [IQR: 43.0, 64.0] years, female 37.3%) with HCM were retrospectively included from May 2019 to April 2021. Among them, 162 patients underwent echocardiographic examination and contrast-enhanced CMR within 7 days. Myo-GLS and %LGE were blindly assessed in a core laboratory. All the patients were followed after they were discharged. During a mean follow-up of 33.77 [IQR 30.05, 35.40] months, 14 participants (7.91%) experienced major adverse cardiac events (MACE). The MACE (+) group showed lower absolute endo-GLS and myo-GLS than the MACE (-) group. Myo-GLS was more associated with %LGE (r=-.68, P<.001) than endo-GLS (r=-.64, P<.001). Cox multivariable analysis indicated that absolute myo-GLS was independently associated with MACE (adjusted hazard ratio=.75, P<.05). Myo-GLS was better than endo-GLS at detecting MACE (+) patients (-8.64%, AUC.939vs. - 16.375%, AUC.898, P<.05). Myo-GLS is a stronger predictor of MACE than endo-GLS in patients with HCM and is highly correlated with %LGE.

Correlation Between Corrected TIMI Frame Count with the Extent of Myocardial Fibrosis on ST-Elevation Myocardial Infarction Patients Undergoing Primary Percutaneous Coronary Intervention

Background: Microvascular injury after primary percutaneous coronary intervention (PPCI) reperfusion contributes to necrosis propagation. Corrected TIMI Frame Count (CTFC) is a surrogate marker of microvascular dysfunction and can stratify in-hospital mortality risk in patients with final TIMI flow 3. The extent of myocardial fibrosis after STEMI is associated with a higher incidence of major cardiovascular events. This study aimed to determine the relationship between CTFC in the infarct-related artery and myocardial fibrosis area based on cardiac magnetic resonance (CMR) in STEMI patients undergoing PPCI.Methods: This retrospective cohort study included 31 STEMI patients who had undergone PPCI and CMR examination between days 60 and 75 after STEMI as the sample. CTFC was measured in the infarct-related artery from post-PPCI angiogram recordings. Myocardial fibrosis area was measured from late gadolinium enhancement CMR (LGE-CMR) imaging results.Results: In this study, the mean age was 51.61±10.49 years, 90.3% were male, non-anterior infarction location was 58.1%, mean total ischemic time was 489.48±228.33 minutes, mean CTFC was 27.4±9.3 frames, and mean myocardial fibrosis was 18.33±7.87%. There was no significant correlation found between CTFC and myocardial fibrosis (p=0.530), however total ischemic time had a positive and significant correlation with myocardial fibrosis (p=0.025, r=0.403).Conclusion: CTFC in the infarct-related artery is not correlated with myocardial fibrosis area in STEMI patients undergoing PCI.

Ventricular arrhythmias in patients with bicuspid aortic valves.

Bicuspid aortic valves (BAV) are the most common congenital heart defects and the extent of ventricular arrhythmias (VA) in patients with BAV is unclear. The objective of this study is to describe VAs and late gadolinium enhancement cardiac magnetic resonance imaging (LGE-CMR) in patients with BAV. A total of 19 patients with BAV (18 males, age: 58 ± 13 years) were referred for VA ablation procedures. Ten patients had BAVs at the time of ablation, nine patients had prior aortic valve replacement for a BAV. All but one patient had LGE-CMR and all patients underwent programmed ventricular stimulation at the time of the ablation. Frequent PVCs were the targeted VAs in 17/19 patients and VT in 2/19 patients. Monomorphic ventricular tachycardia (VT) was inducible in 6 patients. A total of 15 VTs were inducible (2.5 ± 1.0 VTs per patient with a mean cycle length of 322 ± 83 msec). LGE was present in 13 patients. Patients with inducible VT had larger borderzone and core scar compared to non-inducible patients (7.8 ± 2.1 cm3 vs. 2.5 ± 3.1 cm3 and 5.1 ± 2.6 cm3 vs. 1.9 ± 3.0 cm3, p-value < .05 for both). PVCs and VTs were mapped to the periaortic valve area in 12 patients and 4 patients, respectively. The PVC burden was reduced from 27 ± 13 to 3 ± 6 (p < .001) and the ejection fraction improved from 49 ± 13% to 55 ± 9% (p = .005). VAs in patients with BAV often originate from the perivalvular area and patients often have LGE and inducible VT. LGE may be due to ventricular remodeling secondary to the presence of BAV and harbors the arrhythmogenic substrate for VT.

Follow-up of intramyocardial bone marrow mononuclear cell transplantation beyond 10 years

Bone marrow mononuclear cells (BMMCs) have been evaluated for their ability to improve cardiac repair and benefit patients with severe ischemic heart disease and heart failure. In our single-center trial in 2006–2011 we demonstrated the safety and efficacy of BMMCs injected intramyocardially in conjunction with coronary artery bypass surgery. The effect persisted in the follow-up study 5 years later. In this study, we investigated the efficacy of BMMC therapy beyond 10 years. A total of 18 patients (46%) died during over 10-years follow-up and 21 were contacted for participation. Late gadolinium enhancement cardiac magnetic resonance imaging (CMRI) and clinical evaluation were performed on 14 patients, seven from each group. CMRIs from the study baseline, 1-year and 5-years follow-ups were re-analyzed to enable comparison. The CMRI demonstrated a 2.1-fold larger reduction in the mass of late gadolinium enhancement values between the preoperative and the over 10-years follow-up, suggesting less scar or fibrosis after BMMC treatment (− 15.1%; 95% CI − 23 to − 6.7% vs. − 7.3%; 95% CI − 16 to 4.5%, p = 0.039), compared to placebo. No differences in mortality or morbidity were observed. Intramyocardially injected BMMCs may exert long-term benefits in patients with ischemic heart failure. This deserves further evaluation in patients who have received BMMCs in international clinical studies over two decades.

Determination of viable myocardium through delayed enhancement cardiac magnetic resonance imaging combined with 18F-FDG PET myocardial perfusion/metabolic imaging before CABG.

Study aims to investigate the consistency of delayed enhancement cardiac magnetic resonance imaging (DE-CMR) and 18F-FDG PET myocardial imaging in evaluating myocardial viability before CABG. The study analyzed data from 100 patients who were examined with DE-CMR, PET imaging, and echocardiography before and after CABG. All subjects were followed up for 6-12 month post- CABG. DE-CMR and PET imaging have high consistency (90.1%; Kappa value = 0.71, p < 0.01) in determining myocardial viability. The degree of delayed enhancement was negatively correlated with the improvement in myocardial contractile function in this segment after revascularization (P < 0.001). The ratio of scarred myocardial segments and total DE score was significantly lower in the improvement group than non-improvement group. Multivariate regression identified that hibernating myocardium (OR = 1.229, 95%CI: 1.053-1.433, p = 0.009) was influencing factor of LVEF improvement after CABG. Both imaging techniques are consistent in evaluating myocardial viability. Detecting the number of hibernating myocardium by PET is also important to predict the left heart function improvement after CABG.

Multi-network approach for image segmentation in non-contrast enhanced cardiac 3D MRI of arrhythmic patients

Left atrial appendage (LAA) is the source of thrombi formation in more than 90% of strokes in patients with nonvalvular atrial fibrillation. Catheter-based LAA occlusion is being increasingly applied as a treatment strategy to prevent stroke. Anatomical complexity of LAA makes percutaneous occlusion commonly performed under transesophageal echocardiography (TEE) and X-ray (XR) guidance especially challenging. Image fusion techniques integrating 3D anatomical models derived from pre-procedural imaging into the live XR fluoroscopy can be applied to guide each step of the LAA closure. Cardiac magnetic resonance (CMR) imaging gains in importance for radiation-free evaluation of cardiac morphology as alternative to gold-standard TEE or computed tomography angiography (CTA). Manual delineation of cardiac structures from non-contrast enhanced CMR is, however, labor-intensive, tedious, and challenging due to the rather low contrast. Additionally, arrhythmia often impairs the image quality in ECG synchronized acquisitions causing blurring and motion artifacts. Thus, for cardiac segmentation in arrhythmic patients, there is a strong need for an automated image segmentation method. Deep learning-based methods have shown great promise in medical image analysis achieving superior performance in various imaging modalities and different clinical applications. Fully-convolutional neural networks (CNNs), especially U-Net, have become the method of choice for cardiac segmentation. In this paper, we propose an approach for automatic segmentation of cardiac structures from non-contrast enhanced CMR images of arrhythmic patients based on CNNs implemented in a multi-stage pipeline. Two-stage implementation allows subdividing the task into localization of the relevant cardiac structures and segmentation of these structures from the cropped sub-regions obtained from previous step leading to efficient and effective way of automated cardiac segmentation.

Quality assurance of late gadolinium enhancement cardiac magnetic resonance images: a deep learning classifier for confidence in the presence or absence of abnormality with potential to prompt real-time image optimization

BackgroundLate gadolinium enhancement (LGE) of the myocardium has significant diagnostic and prognostic implications, with even small areas of enhancement being important. Distinguishing between definitely normal and definitely abnormal LGE images is usually straightforward; but diagnostic uncertainty arises when reporters are not sure whether the observed LGE is genuine or not. This uncertainty might be resolved by repetition (to remove artefact) or further acquisition of intersecting images, but this must take place before the scan finishes. Real-time quality assurance by humans is a complex task requiring training and experience, so being able to identify which images have an intermediate likelihood of LGE while the scan is ongoing, without the presence of an expert is of high value. This decision-support could prompt immediate image optimisation or acquisition of supplementary images to confirm or refute the presence of genuine LGE. This could reduce ambiguity in reports. MethodsShort-axis, phase sensitive inversion recovery (PSIR) late gadolinium images were extracted from our clinical CMR database and shuffled. Two, independent, blinded experts scored each individual slice for ‘LGE likelihood’ on a visual analogue scale, from 0 (absolute certainty of no LGE) to 100 (absolute certainty of LGE), with 50 representing clinical equipoise. The scored images were split into 2 classes – either “high certainty” of whether LGE was present or not, or “low certainty”. The dataset was split into training, validation and test sets (70:15:15). A deep learning binary classifier based on the EfficientNetV2 convolutional neural network architecture was trained to distinguish between these categories. Classifier performance on the test set was evaluated by calculating the accuracy, precision, recall, F1-score, and area under the receiver operating characteristics curve (ROC AUC). Performance was also evaluated on an external test set of images from a different centre. Results1645 images (from 272 patients) were labelled and split at the patient level into training (1151 images), validation (247 images) and test (247 images) sets for the deep learning binary classifier. Of these, 1208 images were ‘high certainty’ (255 for LGE, 953 for no LGE), and 437 were ‘low certainty’). An external test comprising 247 images from 41 patients from another centre was also employed. After 100 epochs the performance on the internal test set was: accuracy = 94%, recall = 0.80, precision = 0.97, F1-score = 0.87 and ROC AUC = 0.94. The classifier also performed robustly on the external test set (accuracy = 91%, recall = 0.73, precision = 0.93, F1-score = 0.82 and ROC AUC = 0.91). These results were benchmarked against a reference inter-expert accuracy of 86%. ConclusionsDeep learning shows potential to automate quality control of late gadolinium imaging in CMR. The ability to identify short-axis images with intermediate LGE likelihood in real-time may serve as a useful decision support tool. This approach has the potential to guide immediate further imaging while the patient is still in the scanner, thereby reducing the frequency of recalls and inconclusive reports due to diagnostic indecision.

Toward Accurate Cardiac MRI Segmentation With Variational Autoencoder-Based Unsupervised Domain Adaptation.

Accurate myocardial segmentation is crucial in the diagnosis and treatment of myocardial infarction (MI), especially in Late Gadolinium Enhancement (LGE) cardiac magnetic resonance (CMR) images, where the infarcted myocardium exhibits a greater brightness. However, segmentation annotations for LGE images are usually not available. Although knowledge gained from CMR images of other modalities with ample annotations, such as balanced-Steady State Free Precession (bSSFP), can be transferred to the LGE images, the difference in image distribution between the two modalities (i.e., domain shift) usually results in a significant degradation in model performance. To alleviate this, an end-to-end Variational autoencoder based feature Alignment Module Combining Explicit and Implicit features (VAMCEI) is proposed. We first re-derive the Kullback-Leibler (KL) divergence between the posterior distributions of the two domains as a measure of the global distribution distance. Second, we calculate the prototype contrastive loss between the two domains, bringing closer the prototypes of the same category across domains and pushing away the prototypes of different categories within or across domains. Finally, a domain discriminator is added to the output space, which indirectly aligns the feature distribution and forces the extracted features to be more favorable for segmentation. In addition, by combining CycleGAN and VAMCEI, we propose a more refined multi-stage unsupervised domain adaptation (UDA) framework for myocardial structure segmentation. We conduct extensive experiments on the MSCMRSeg 2019, MyoPS 2020 and MM-WHS 2017 datasets. The experimental results demonstrate that our framework achieves superior performances than state-of-the-art methods.

Catheter Ablation of Persistent AF-Where are We Now?

Persistent atrial fibrillation (AF) is a diverse condition that includes various subtypes and underlying causes of arrhythmia. Progress made in catheter ablation technology in recent years has significantly enhanced the durability of ablation. Despite these advances however, the effectiveness of ablation in treating persistent AF is still relatively modest. Studies exploring the mechanisms behind persistent AF have identified substrate-driven focal and re-entrant sources within the atrial body as crucial in sustaining AF among individuals with persistent AF. Furthermore, the widespread adoption of atrial late gadolinium enhancement cardiac magnetic resonance (CMR) imaging and the ongoing refinement of invasive voltage mapping techniques have allowed for detailed assessment of fibrotic remodelling prior to or at the time of procedure. Translation into clinical practice, however, has yielded overall disappointing results. The clinical application of AF mapping in ablation procedures has not shown any substantial advantages beyond the use of pulmonary vein isolation (PVI) alone and adjunct ablation of fibrotic areas has yielded conflicting results in recent randomized trials. The emergence of pulsed field ablation represents a welcome development in the field and several studies have demonstrated an enhanced safety profile and increased procedural efficiency with this non-thermal energy modality. Pulsed field ablation also holds promise for safe and efficient substrate ablation beyond the pulmonary veins, but further trials are needed to assess its impact on longer term success rates. Continued advancements in our comprehension of AF mechanisms, alongside ongoing developments in catheter technology aimed at safe formation of transmural lesions, are essential for achieving better clinical outcomes for patients with persistent AF.

Prognostic implications of papillary muscle delayed hyperenhancement in dilated cardiomyopathy patients

Abstract Background Similar to left ventricle (LV) myocardial delayed hyperenhancement (HE), papillary muscle delayed hyperenhancement (papHE) at cardiac magnetic resonance (CMR) may indicate fibrotic or infiltrative processes. The prevalence in patients with non-ischemic dilated cardiomyopathy (DCM) and its impact on outcome are unknown. Objectives We aimed to determine the prevalence of papHE in an outpatient DCM cohort with longitudinal follow-up. Methods From the Maastricht Cardiomyopathy Registry, we included 528 consecutive patients who underwent Late Gadolinium Enhancement (LGE) Cardiac Magnetic Resonance imaging (CMR), and both papHE and papillary tip delayed hyperenhancement (tipHE) were assessed. The primary outcomes were all-cause mortality, sudden cardiac death, life-threatening arrhythmia, and hospitalization for heart failure (HFH). Unadjusted Kaplan Meier curves were constructed and compared using log-rank tests. PapHE was related to outcomes, using univariable and multivariable Cox regression analysis, correcting for clinical covariables (age, sex, and LV ejection fraction). In a second model, we corrected for myocardial HE, on top of the covariables included in the first model. Mitral valve regurgitation was assessed during follow-up echocardiography in 409 patients (77%). Results Three hundred and twenty five patients (62%) had tipHE and 131 patients (25%) had papHE. The median follow-up duration was 5.6 (IQR 3.5-9.0) years. PapHE was associated with all-cause mortality (HR=1.76, 95% CI 1.04-2.97), sudden cardiac death (HR=2.23, 95% CI 1.10-4.54) and HFH (HR=2.42, 95% CI 1.16-5.06), but not with life-threatening arrhythmias, after correction for clinical covariables. The presence of isolated tipHE was not associated with adverse outcomes. The correlation of myocardial HE was stronger than that of papHE, specifically with sudden cardiac death (HR=2.40, 95% CI 1.10-5.23 for myocardial HE) and life-threatening arrhythmias (HR=2.97, 95% CI 1.04-8.46 for myocardial HE). Additional correction for myocardial HE rendered the correlation between papHE and the studied outcomes insignificant. Finally, papHE did not correlate to mitral regurgitation. Conclusions PapHE is present in 25% of DCM patients. The presence of papHE correlated with sudden cardiac death and HFH, still myocardial HE remains a stronger predictor. Our results support the incorporation of myocardial HE in implantable cardioverter-defibrillator guideline recommendations. Future studies should investigate if the addition of PapHE helps to improve such guidelines further.

Long-term outcomes of patients with ventricular arrhythmias and negative programmed ventricular stimulation followed with implantable loop recorders: Impact of delayed-enhancement cardiac magnetic resonance imaging.

Programed ventricular stimulation (PVS) is a risk stratification tool in patients at risk for adverse arrhythmia outcomes. Patients with negative PVS may yet be at risk for adverse arrhythmia-related events, particularly in the presence of symptomatic ventricular arrhythmias (VA). To investigate the long-term outcomes of real-world patients with symptomatic VA without indication for device therapy and negative PVS, and to examine the role of cardiac scaring on arrhythmia recurrence. Patients with symptomatic VA, and late gadolinium enhancement cardiac magnetic resonance imaging (LGE-CMR), and negative PVS testing were included. All patients underwent placement of implantable cardiac monitors (ICM). Survival analysis was performed to investigate the impact of LGE-CMR findings on survival free from adverse arrhythmic events. Seventy-eight patients were included (age 60 ± 14 years, women n = 36 (46%), ejection fraction 57 ± 9%, cardiomyopathy n = 26 (33%), mitral valve prolapse [MVP] n = 9 (12%), positive LGE-CMR scar n = 49 (62%), history of syncope n = 23 (29%))including patients with primarily premature ventricular contractions (n = 21) or nonsustained VA (n = 57). Patients were followed for 1.6 ± 1.5 years during which 14 patients (18%) experienced VA requiring treatment (n = 14) or syncope due to bradycardia (n = 2). Four/9 patients (44%) with MVP experienced VA (n = 3) or syncope (n = 1). Baseline characteristics between those with and without adverse events were similar (p > 0.05); however, the presence of cardiac scar on LGE-CMR was independently associated with an increased risk of adverse events (hazard ratio: 5.6 95% confidence interval:[1.2-27], p = 0.03, log-rank p = 0.03). In a real-world cohort with long-term follow-up, adverse arrhythmic outcomes occurred in 18% of patients with symptomatic VA despite negative PVS, and this risk was significantly greater in patients with positive DE-CMR scar. Long term-monitoring, including the use of ICM, may be appropriate in these patients.

Electrocardiographic characteristics associated with late gadolinium enhancement and prognostic value in patients with dilated cardiomyopathy.

Late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) imaging has emerged as an important tool for assessment of patients with dilated cardiomyopathy (DCM). Electrocardiography (ECG) is an accessible, reproducible, low-cost diagnostic and prognostic tool. This study aimed to investigate the ECG characteristics associated with LGE, as well as to assess the prognostic significance of ECG in patients with DCM. Consecutive patients diagnosed with DCM by CMR [left ventricular ejection fraction (LVEF) < 50%] between 2011 and 2020 were included. Multivariable analysis was conducted to evaluate ECG predictors associated with LGE. Receiver operating characteristic (ROC) analysis was performed to assess the diagnostic performance of ECG in combination of clinical data and LVEF for LGE. Two composite outcomes were also assessed among patients with and without ECG predictors: (1) sudden cardiac death (SCD), sustained ventricular arrhythmia, or appropriate implantable cardioverter-defibrillator (ICD) therapy, and (2) all-cause death or hospitalization for heart failure. A total of 422 patients, with a mean age of 59.5 ± 16.3 years (58.3% male), were included. LGE was present in 169 (40%) of the patients. Multivariable analysis identified lateral inverted T-waves, intraventricular conduction delay, low voltage, and fragmented QRS as independent predictors of LGE. ROC analysis showed a significant increase in the area under the curve (AUC) when ECG predictors of the four aforementioned characteristics were added to the clinical-LVEF model (AUC 0.66, 95% CI 0.59-0.71 vs. 0.72, 95% CI 0.67-0.78, p = 0.003). During a median follow-up of 2.7 years (IQR 0.8, 5.2), 16 events of SCD, sustained ventricular arrhythmia, or appropriate ICD therapy, and 70 events of all-cause death or hospitalization for heart failure occurred. ECG predictors were independently associated with SCD, sustained ventricular arrhythmia, or appropriate ICD therapy (HR 4.84, 95% CI 1.34-17.40, p = 0.01). However, ECG predictors were not associated with all-cause death or hospitalization for heart failure (HR 1.22, 95% CI 0.76-1.96, p = 0.39). In patients with DCM, lateral inverted T-waves, intraventricular conduction delay, low voltage, and fragmented QRS were independently associated with LGE. Additionally, these ECG predictors had prognostic value for predicting SCD, sustained ventricular arrhythmia, or appropriate ICD therapy, assisting clinicians in stratifying SCD risk and identifying primary prevention ICD implantation candidates.

Поражение сердца у юных элитных спортсменов, перенесших COVID-19

The impact of coronavirus infection (SARS-CoV-2) on cardiac output in underage athletes is uncertain. The study was aimed to determine heart disease in young elite athletes having a history of COVID-19 (SARS-CoV-2). A retrospective analysis of the results of the developed three-phase medical assessment of 236 elite athletes aged 14–17 (16 ± 1), who had had SARS-CoV-2 infection, was performed. The first phase of assessment involved examination, ECG, ECHO, bicycle ergometry (BEM), creatine kinase and creatine kinase MB tests. During the second phase 22 athletes (9.3%) underwent a more thorough assessment that included Holter monitoring (HM) with heart rate turbulence (HRT), microvolt T–wave alternans (MTWA), heart rate variability (HRV) estimation, high-resolution ECG (HRECG), determination of myocardial damage biochemical markers (troponin, NТproBNP) due to alterations revealed. Seven athletes (32%) having alterations revealed during this phase were referred to gadolinium enhancement cardiac magnetic resonance imaging (MRI) (the third phase). Myopericarditis was diagnosed in four cases (1.7% of 236) based on the results. Thus, low (below 2%) myocardial involvement has been revealed in young elite athletes, who have a history of SARSCoV-2 infection. Cardiovascular assessment algorithm has been developed for such athletes. Detection of cardiac arrhythmias by ECG, BEM, and HM is the most informative. HRECG, HRV, HRT, and MTWA can be used as additional methods to determine indications for MRI as a gold standard of the diagnosis of myocarditis.

Impact of late gadolinium-enhanced cardiac MRI on arrhythmic and mortality outcomes in nonischemic dilated cardiomyopathy: updated systematic review and meta-analysis

Risk stratification based mainly on the impairment of left ventricular ejection fraction has limited performance in patients with nonischemic dilated cardiomyopathy (NIDCM). Evidence is rapidly growing for the impact of myocardial scar identified by late gadolinium enhancement (LGE) cardiac magnetic resonance imaging (CMR) on cardiovascular events. We aim to assess the prognostic value of LGE on long-term arrhythmic and mortality outcomes in patients with NIDCM. PubMed, Scopus, and Cochrane databases were searched from inception to January 21, 2022. Studies that included disease-specific subpopulations of NIDCM were excluded. Data were independently extracted and combined via random-effects meta-analysis using a generic inverse-variance strategy. Data from 60 studies comprising 15,217 patients were analyzed with a 3-year median follow-up. The presence of LGE was associated with major ventricular arrhythmic events (pooled OR: 3.99; 95% CI 3.08, 5.16), all-cause mortality (pooled OR: 2.14; 95% CI 1.81, 2.52), cardiovascular mortality (pooled OR 2.83; 95% CI 2.23, 3.60), and heart failure hospitalization (pooled OR: 2.53; 95% CI 1.78, 3.59). Real-world evidence suggests that the presence of LGE on CMR was a strong predictor of adverse long-term outcomes in patients with NIDCM. Scar assessment should be incorporated as a primary determinant in the patient selection criteria for primary prophylactic implantable cardioverter-defibrillator placement.

Value of genotyping and scar-phenotyping for VT ablation procedures in patients with nonischemic left ventricular cardiomyopathies.

Variants of cardiomyopathy genes in patients with nonischemic cardiomyopathy (NICM) generate various phenotypes of cardiac scar and delayed enhancement cardiac magnetic resonance (DE-CMR) imaging which may impact ventricular tachycardia (VT) management. The objective was to compare the findings of cardiomyopathy genetic testing on DE-CMR imaging and long-term outcomes among patients with NICM undergoing VT ablation procedures. Image phenotyping and genotyping were performed in a consecutive series of patients referred for VT ablation and correlated to survival free of VT. Scar depth index (SDI) (% of scar at 0-3 mm, 3-5 mm and >5 mm projected on the closest endocardial surface) was determined. Forty-three patients were included (11 women, 55 ± 14 years, ejection fraction (EF) 45 ± 16%) and were followed for 3.4 ± 2.9 years. Pathogenic variants (PV) were identified in 16 patients (37%) in the following genes: LMNA (n = 5), TTN (n = 5), DSP (n = 2), AMLS1 (n = 1), MYBPC3 (n = 1), PLN (n = 1), and SCN5A (n = 1). A ring-like septal scar (RLSS) pattern was more often seen in patients with pathogenic variants (66% vs 15%, p = .001). RLSS was associated with deeper seated scars (SDI >5 mm 30.6 ± 22.6% vs 12.4 ± 16.2%, p = .005), and increased VT recurrence (HR 5.7 95% CI[1.8-18.4], p = .003). After adjustment for age, sex, EF, and total scar burden, the presence of a PV remained independently associated with worse outcomes (HR 4.7 95% CI[1.22-18.0], p = .02). Preprocedural genotyping and scar phenotyping is beneficial to identify patients with a favorable procedural outcome. Some PVs are associated with an intramural, deeper seated scar phenotype and have an increase of VT recurrence after ablation.

The Role of Echocardiography in the Contemporary Diagnosis and Prognosis of Cardiac Sarcoidosis: A Comprehensive Review.

Cardiac sarcoidosis (CS) is a rare inflammatory disorder characterised by the presence of non-caseating granulomas within the myocardium. Contemporary studies have revealed that 25-30% of patients with systemic sarcoidosis have cardiac involvement, with detection rates increasing in the era of advanced cardiac imaging. The use of late gadolinium enhancement cardiac magnetic resonance and 18fluorodeoxy glucose positron emission tomography (FDG-PET) imaging has superseded endomyocardial biopsy for the diagnosis of CS. Echocardiography has historically been used as a screening tool with abnormalities triggering the need for advanced imaging, and as a tool to assess cardiac function. Regional wall thinning or aneurysm formation in a noncoronary distribution may indicate granuloma infiltration. Thinning of the basal septum in the setting of extracardiac sarcoidosis carries a high specificity for cardiac involvement. Abnormal myocardial echotexture and eccentric hypertrophy may be suggestive of active myocardial inflammation. The presence of right-ventricular involvement as indicated by free-wall aneurysms can mimic arrhythmogenic right-ventricular cardiomyopathy. More recently, the use of myocardial strain has increased the sensitivity of echocardiography in diagnosing cardiac involvement. Echocardiography is limited in prognostication, with impaired left-ventricular (LV) ejection fraction and LV dilatation being the only established independent predictors of mortality. More research is required to explore how advanced echocardiographic technologies can increase both the diagnostic sensitivity and prognostic ability of this modality in CS.