Prognostic value of strain by feature-tracking cardiac magnetic resonance in arrhythmogenic right ventricular cardiomyopathy

Prognostic impact of left ventricular strain by feature tracking in acute myocardial infarction treated with PCI: A meta-analysis

PURPOSE

To perform a meta-analysis to evaluate the prognostic value of feature tracking (FT)-derived left ventricular (LV) strain parameters in patients following acute myocardial infarction (AMI).

MATERIALS AND METHODS

We conducted a comprehensive search of PubMed, Embase, and the Cochrane library for studies published between January 2000 and July 2024, evaluating the prognostic value of FT-derived LV strain parameters in predicting major adverse cardiovascular events (MACE) in patients following AMI. We included studies of patients who underwent cardiac magnetic resonance feature tracking analysis following reperfusion by percutaneous coronary intervention (PCI), as well as reporting multivariate analyses of global longitudinal strain (GLS) or global circumferential strain (GCS). Using RStudio, we calculated pooled hazard ratios (HR) with 95 % confidence intervals (CI) using random-effects models and evaluated heterogeneity with I2 statistics.

RESULTS

Nine studies involving 3651 patients were included. Seven studies focused on GLS, while five evaluated GCS in relation to MACE. The meta-analysis revealed a significant association between GLS and MACE occurrence (HR 1.15; 95 % CI: 1.07-1.23; I2 = 76 %; p ≤ 0.0001). For GCS, the pooled HR was 1.11 (95 % CI: 1.04-1.19; I2 = 50 %; p = 0.0024). However, a leave-one-out sensitivity analysis showed that the prognostic effect of GCS was not robust, as the pooled HR adjusted to 1.09 (95 % CI: 1.00-1.19).

CONCLUSION

GLS was identified as a sensitive marker of early myocardial injury with incremental prognostic value, potentially enhancing risk stratification for post-AMI patients. Conversely, GCS did not demonstrate a significant prognostic effect.

Prognostic value of magnetic resonance imaging (MRI)-based cardiac adipose tissue in arrhythmogenic right ventricular cardiomyopathy

AIM

The aim of this study was to explore the relationship between epicardial adipose tissue (EAT), paracardial adipose tissue (PaAT), pericardial adipose tissue (PeAT), and fat ratio with left ventricular (LV) involvement, assessing the prognostic significance of cardiac fat in arrhythmogenic right ventricular cardiomyopathy (ARVC).

MATERIALS AND METHODS

Ninety-two ARVC patients (mean age: 45.74 years; 63% male) were included and followed up for 92 months. Measured in cardiac magnetic resonance imaging (MRI) cine views, EAT, PaAT, PeAT, and fat ratio (EAT/PaAT) were analyzed to identify the association with major adverse cardiac events (MACEs) (sudden cardiovascular death, aborted cardiac arrest, heart failure hospitalization, and sustained documented ventricular tachycardia).

RESULTS

Among the 92 participants, 28 (30.43%) MACEs occurred during the follow-up. Significantly higher EAT, PaAT, PeAT, and fat ratio were observed in patients with LV involvement than in those without (p = 0.001, p = 0.002, p = 0.001, p = 0.003, respectively) in violin plots. A worse prognosis in ARVC patients was associated with a higher volume of EAT (log rank p = 0.0031). In multivariate Cox regression analysis, EAT (Hazard Ratio [HR]: 1.056, 95% confidence interval [CI]: 1.011-1.103, p = 0.013) and 5-year risk score (HR: 1.018, 95% CI: 1.002-1.034, p = 0.030) were identified as independent prognostic predictors for MACEs. Additional prognostic information over conventional outcome predictors was provided by EAT (Uno C-statistics: 0.645 vs. 0.665, p = 0.007).

CONCLUSION

higher cardiac fat volume was found to be correlated with LV involvement. Independent risk factors for MACEs in ARVC were identified as EAT and 5-year risk score, and the incremental prognostic value to established predictors in ARVC was provided by EAT.

Ventricular Discordance as an MRI Phenotype Provides Prognostic Value Among Arrhythmogenic Cardiomyopathy

BACKGROUND

In arrhythmogenic cardiomyopathy (ACM), left ventricle-dominant presentation has poorer outcomes than right-dominant presentation, suggesting that interventricular functional disparity might play a role in patients' prognosis. However, the prognostic impact of ventricular functional discordance in ACM patients remains unknown.

PURPOSE

To assess whether ventricular functional disparity measured as ventricular discordance index, defined as the ratio of right-ventricular ejection fraction (RVEF) to left-ventricular ejection fraction (LVEF), might reveal prognostic disparities between phenotypes and offer added risk stratification value.

STUDY TYPE

Retrospective.

SUBJECTS

A total of 222 patients with ACM (mean age 44 ± 16 years, 144 males) from three centers were included.

FIELD STRENGTH/SEQUENCE

3-T, cine imaging.

ASSESSMENT

Ventricular discordance index was calculated using cine-derived RVEF and LVEF, for which a threshold was determined using Youden J index. Clinically ventricular discordance was defined as ventricular discordance index above the threshold. The major adverse cardiac events (MACE), was defined as sudden cardiac death, appropriate implantable cardioverter-defibrillator intervention, and aborted cardiac arrest. International task diagnostic force criteria and the 5-year risk score were evaluated.

STATISTICAL TESTS

The prognostic implications of ventricular discordance index and clinically ventricular discordance were evaluated using multivariable Cox analysis. P < 0.05 indicated the statistical significance.

RESULTS

During a median follow-up of 50 months, 81 (37%) patients experienced MACE. The ventricular discordance index was independently associated with MACE (hazard ratio [HR]: 1.49; 95% confidence interval [CI]: 1.23-1.82). Patients classified under clinically ventricular discordance experienced higher MACE rates and were less likely to meet the task force structural criteria. clinically ventricular discordance was independently associated with MACE (adjusted HR: 2.2; 95% CI: 1.36-3.55). Clinically ventricular discordance, LV involvement and the 5-year risk score in combined reclassified 20.3% of patients compared to 2015 task force classification.

DATA CONCLUSION

Ventricular discordance was associated with MACE in ACM, potentially providing prognostic value beyond the 5-year risk score.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY: 5.

Adolescent Reference Values for MR-Derived Biventricular Strain Obtained Using Feature-Tracking and Myocardial Tagging

BACKGROUND

Myocardial strain is a promising marker for the detection of early left or right ventricular (LV or RV) dysfunction in pediatric populations. The reference standard for MR strain measurement is myocardial tagging (MT); however, MT has limited clinical utility because the additional acquisitions needed are time-consuming. In contrast, MR-feature tracking (FT) allows strain quantification from routinely acquired cine sequences. Studies providing reference values obtained with both FT and MT for adolescents are lacking.

PURPOSE

To use MR-FT and MT to define sex-specific LV and RV strain reference values for adolescents.

STUDY TYPE

Cross-sectional, prospective.

POPULATION

One hundred twenty-three adolescents aged 15-18 years (52% girls) without known cardiovascular disease.

FIELD STRENGTH/SEQUENCE

Balanced steady-state free-precession sequence for FT analysis and a spatial modulation of magnetization hybrid TFE-EPI sequence for MT acquisitions at 3.0-T.

ASSESSMENT

Segment Medviso software was used to obtain longitudinal (LS) and circumferential (CS) strain for both ventricles, and radial strain (RS) for LV.

STATISTICAL TESTS

The Student t-test was used for between-sex comparisons of continuous variables. Sex-specific percentiles were calculated using the weighted average method. Intraobserver and interobserver agreement was assessed in 30 randomly selected studies using intraclass correlation coefficients (ICC). A P-value <0.05 was considered statistically significant.

RESULTS

FT-derived LVLS and LVCS were significantly higher in girls than in boys (-19.8% vs. -17.8% and -22.2% vs. -21.0%, respectively), as they were with MT (LVLS: -18.1% vs. -16.8%; LVCS: -20.8% vs. -19.7%). FT-LVRS was higher in girls than in boys (44.8% vs. 35.1%), while MT-LVRS was the opposite (18.6% vs. 22.7%). FT-RVLS was higher in girls (-23.4% vs. -21.3%), but there were no between-sex differences in MT-derived RVLS or RVCS. ICC values for intraobserver agreement were ≥0.89, whereas for interobserver agreement were <0.80 for MT-LVRS and ≥0.80 for all remaining parameters.

DATA CONCLUSION

This study provides sex-specific reference biventricular strain values obtained with MR-MT and MR-FT for adolescents aged 15-18 years. MR-FT may be a valid method for obtaining strain values in pediatric populations.

EVIDENCE LEVEL

1 TECHNICAL EFFICACY: Stage 3.

Cardiac Magnetic Resonance Imaging in the Evaluation of Functional Impairments in the Right Heart

Cardiac magnetic resonance (cMRI) imaging has recently become essential in cardiology. cMRI is widely recognized as the most reliable imaging technique for assessing the size and performance of the right ventricle. It allows for objective and functional cardiac tissue evaluations. Early in disease progression, cardiac structure and activity decrease subclinically. Late-phase clinically visible signs have been associated with less favourable outcomes. Subclinical alterations ought to be recognized for rapid evaluations and accurate treatment. An increasing amount of evidence supports cMRI deformation parameter quantification. Strain imaging enables cardiologists to assess heart function beyond traditional measurements. Prognostic information for cardiovascular disease patients is obtained through the right ventricle (RV) strain, including information primarily about the left ventricle (LV). Right atrial (RA) function evaluations using RA strain have been promising in recent studies. Therefore, this narrative review aims to present an overview of the data that are currently available for assessing right myocardial strain and biomechanics using cMRI.

3D Fractal Dimension Analysis: Prognostic Value of Right Ventricular Trabecular Complexity in Participants with Arrhythmogenic Cardiomyopathy

BACKGROUND

Arrhythmogenic cardiomyopathy (ACM) is characterized by progressive myocardial fibro-fatty infiltration accompanied by trabecular disarray. Traditionally, two-dimensional (2D) instead of 3D fractal dimension (FD) analysis has been used to evaluate trabecular disarray. However, the prognostic value of trabecular disorder assessed by 3D FD measurement remains unclear.

PURPOSE

To investigate the prognostic value of right ventricular trabecular complexity in ACM patients using 3D FD analysis based on cardiac MR cine images.

STUDY TYPE

Retrospective.

POPULATION

85 ACM patients (mean age: 45 ± 17 years, 52 male).

FIELD STRENGTH/SEQUENCE

3.0T/cine imaging, T2-short tau inversion recovery (T2-STIR), and late gadolinium enhancement (LGE).

ASSESSMENT

Using cine images, RV (right ventricular) volumetric and functional parameters were obtained. RV trabecular complexity was measured with 3D fractal analysis by box-counting method to calculate 3D-FD. Cox and logistic regression models were established to evaluate the prognostic value of 3D-FD for major adverse cardiac events (MACE).

STATISTICAL TESTS

Cox regression and logistic regression to explore the prognostic value of 3D-FD. C-index, time-dependent receiver operating characteristic (ROC) curves and area under the ROC curve (AUC) to evaluate the incremental value of 3D-FD. Intraclass correlation coefficient for interobserver variability. P < 0.05 indicated statistical significance.

RESULTS

26 MACE were recorded during the 60 month follow-up (interquartile range: 48-67 months). RV 3D-FD significantly differed between ACM patients with MACE (2.67, interquartile range: 2.51 ~ 2.81) and without (2.52, interquartile range: 2.40 ~ 2.67) and was a significant independent risk factor for MACE (hazard ratio, 1.02; 95% confidence interval: 1.01, 1.04). In addition, prognostic model fitness was significantly improved after adding 3D-FD to RV global longitudinal strain, LV involvement, and 5-year risk score separately.

DATA CONCLUSION

The myocardial trabecular complexity assessed through 3D FD analysis was found associated with MACE and provided incremental prognostic value beyond conventional ACM risk factors.

EVIDENCE LEVEL

4 TECHNICAL EFFICACY: Stage 1.

Incremental Prognostic Value of Cardiac MRI Feature Tracking and T1 Mapping in Arrhythmogenic Right Ventricular Cardiomyopathy

Purpose To explore the role of cardiac MRI feature tracking (FT) and T1 mapping in predicting sustained ventricular arrhythmias (VA) in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) and to investigate their possible incremental value beyond ARVC risk score. Materials and Methods The retrospective study analyzed 91 patients with ARVC (median age, 36 years [IQR, 27-50 years]; 60 male, 31 female) who underwent cardiac MRI examinations between November 2010 and March 2022. The primary end point was the first occurrence of sustained VA after cardiac MRI to first VA, with censoring of patients who were alive without VA at last follow-up. Cox regression analysis was performed to assess the association between variables and time to sustained VA. Time-dependent receiver operating characteristic (ROC) analysis was performed to determine the incremental value of cardiac MRI FT and T1 mapping. Results During a median follow-up of 55.0 months (IQR, 37.0-76.0 months), 36 of 91 (40%) patients experienced sustained VA. A 1% worsening in left ventricular global longitudinal peak strain (GLS), 1% worsening in right ventricular GLS, and a 1% increase in extracellular volume fraction (ECV) were associated with increased risk of sustained VA, with hazard ratios of 1.14 (95% CI: 1.06, 1.23; P = .001), 1.09 (95% CI: 1.02, 1.16; P = .02), and 1.13 (95% CI: 1.08, 1.18; P < .001), respectively, after adjustment for ARVC risk score. Adding both biventricular GLS and ECV to ARVC risk score showed significant incremental value for predicting sustained VA (area under the ROC curve: 0.73 vs 0.65; P < .001). Conclusion Cardiac MRI-derived biventricular GLS and ECV provided independent and incremental value for predicting sustained VA beyond ARVC risk score alone in patients with ARVC. Keywords: Cardiovascular MRI, Feature Tracking, T1 Mapping, Arrhythmogenic Right Ventricular Cardiomyopathy, Sustained Ventricular Arrhythmias Supplemental material is available for this article Published under a CC BY 4.0 license.

Value of cardiac magnetic resonance feature-tracking in Arrhythmogenic Cardiomyopathy (ACM): A systematic review and meta-analysis

We aimed to assess the diagnostic performance of Cardiac Magnetic Resonance (CMR) strain parameters in ACM patients to evaluate their diagnostic role. We systematically searched MEDLINE, EMBASE, Scopus, and Web of Science. Of the 146 records, 16 were included. All Right Ventricle (RV) global strains were significantly reduced in ACM patients compared to controls (Standardized Mean Difference (SMD)[95 % Confidence Interval (CI)]: Longitudinal 1.31[0.79,1.83]; Circumferential 0.88[0.34,1.42]; Radial -1.14[-1.78,-0.51]). Similarly, all Left Ventricle (LV) global strains were significantly impaired in ACM compared to healthy controls (SDM [95 %CI]: Longitudinal 0.88[0.48,12.28], Circumferential 0.97[0.72,1.22], Radial -1.24[-1.49,-1.00]). Regarding regional RV strains, longitudinal and circumferential strains were significantly reduced in basal and mid-wall regions, while they were comparable to controls in the apical regions. The RV radial strain was reduced only within the basal region in the ACM group compared to controls. ACM patients exhibited significant impairment of regional LV strains in all regions-basal, mid-wall, and apical-compared to control subjects. Ultimately, despite the limitations of CMR-FT in terms of reproducibility, it is superior to qualitative assessment in detecting wall motion abnormalities. Thus, integrating CMR-FT with ACM diagnostic criteria seems to enhance its diagnostic yield.

Right Ventricular Strain Derived from Cardiac MRI Feature Tracking for the Diagnosis and Prognosis of Arrhythmogenic Right Ventricular Cardiomyopathy

Purpose To demonstrate the myocardial strain characteristics of patients with arrhythmogenic right ventricular cardiomyopathy (ARVC), based on revised Task Force Criteria (rTFC), and to explore the prognostic value of strain analysis in ARVC. Materials and Methods This retrospective study included 247 patients (median age, 38 years [IQR, 28-48 years]; 167 male, 80 female) diagnosed with ARVC, based on rTFC, between 2014 and 2018. Patients were divided into "possible" (n =25), "borderline" (n = 40), and "definite" (n = 182) ARVC groups following rTFC. Biventricular global strain parameters were calculated using cardiac MRI feature tracking (FT). The primary outcome was defined as a composite of cardiovascular events, including cardiovascular death, heart transplantation, and appropriate implantable cardioverter defibrillator discharge. Univariable and multivariable cumulative logistic regression and Cox proportional hazards regression analysis were used to evaluate the diagnostic and prognostic value of right ventricle (RV) strain parameters. Results Patients with definite ARVC had significantly reduced RV global strain in all three directions compared with possible or borderline groups (all P < .001). RV global longitudinal strain (GLS) was an independent predictor for disease (odds ratio, 1.09 [95% CI: 1.02, 1.16]; P = .009). During a median follow-up of 3.4 years (IQR, 2.0-4.9 years), 55 patients developed primary end point events. Multivariable analysis showed that RV GLS was independently associated with the occurrence of cardiovascular events (hazard ratio, 1.15 [95% CI: 1.07, 1.24]; P < .001). Kaplan-Meier analysis showed that patients with RV GLS worse than median had a higher risk of combined cardiovascular events (log-rank P < .001). Conclusion RV GLS derived from cardiac MRI FT demonstrated good diagnostic and prognostic value in ARVC. Keywords: MR Imaging, Image Postprocessing, Cardiac, Right Ventricle, Cardiomyopathies, Arrhythmogenic Right Ventricular Cardiomyopathy, Revised Task Force Criteria, Cardiovascular MR, Feature Tracking, Cardiovascular Events Supplemental material is available for this article. © RSNA, 2024.

Cardiac magnetic resonance in advanced heart failure

Heart failure (HF) is a chronic and progressive disease that often progresses to an advanced stage where conventional therapy is insufficient to relieve patients' symptoms. Despite the availability of advanced therapies such as mechanical circulatory support or heart transplantation, the complexity of defining advanced HF, which requires multiple parameters and multimodality assessment, often leads to delays in referral to dedicated specialists with the result of a worsening prognosis. In this review, we aim to explore the role of cardiac magnetic resonance (CMR) in advanced HF by showing how CMR is useful at every step in managing these patients: from diagnosis to prognostic stratification, hemodynamic evaluation, follow-up and advanced therapies such as heart transplantation. The technical challenges of scanning advanced HF patients, which often require troubleshooting of intracardiac devices and dedicated scans, will be also discussed.

Imaging Features of Arrhythmogenic Cardiomyopathies

Arrhythmogenic cardiomyopathy (ACM) is a genetic disease characterized by replacement of ventricular myocardium with fibrofatty tissue, predisposing the patient to ventricular arrhythmias and/or sudden cardiac death. Most cases of ACM are associated with pathogenic variants in genes that encode desmosomal proteins, an important cell-to-cell adhesion complex present in both the heart and skin tissue. Although ACM was first described as a disease predominantly of the right ventricle, it is now acknowledged that it can also primarily involve the left ventricle or both ventricles. The original right-dominant phenotype is traditionally diagnosed using the 2010 task force criteria, a multifactorial algorithm divided into major and minor criteria consisting of structural criteria based on two-dimensional echocardiographic, cardiac MRI, or right ventricular angiographic findings; tissue characterization based on endomyocardial biopsy results; repolarization and depolarization abnormalities based on electrocardiographic findings; arrhythmic features; and family history. Shortfalls in the task force criteria due to the modern understanding of the disease have led to development of the Padua criteria, which include updated criteria for diagnosis of the right-dominant phenotype and new criteria for diagnosis of the left-predominant and biventricular phenotypes. In addition to incorporating cardiac MRI findings of ventricular dilatation, systolic dysfunction, and regional wall motion abnormalities, the new Padua criteria emphasize late gadolinium enhancement at cardiac MRI as a key feature in diagnosis and imaging-based tissue characterization. Conditions to consider in the differential diagnosis of the right-dominant phenotype include various other causes of right ventricular dilatation such as left-to-right shunts and variants of normal right ventricular anatomy that can be misinterpreted as abnormalities. The left-dominant phenotype can mimic myocarditis at imaging and clinical examination. Additional considerations for the differential diagnosis of ACM, particularly for the left-dominant phenotype, include sarcoidosis and dilated cardiomyopathy. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Prognostic value of right atrial strains in arrhythmogenic right ventricular cardiomyopathy

OBJECTIVES

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited cardiomyopathy characterized by progressive fibrofatty infiltration of atrial and ventricular myocardium resulting in adverse cardiac events. Atrial function has been increasingly recognized as prognostically important for cardiovascular disease. As the right atrial (RA) strain is a sensitive parameter to describe RA function, we aimed to analyze the prognostic value of the RA strain in ARVC.

METHODS

RA strain parameters were derived from cardiac magnetic resonance (CMR) images of 105 participants with definite ARVC. The endpoint was defined as a combination of sudden cardiac death, survival cardiac arrest, and appropriate implantable cardioverter-defibrillator intervention. Cox regression and Kaplan-Meier survival analyses were performed to evaluate the association between RA strain parameters and endpoint. Concordance index (C index), net reclassification index (NRI), and integrated discrimination improvement (IDI) were calculated to assess the incremental value of RA strain in predicting the endpoint.

RESULTS

After a median follow-up of 5 years, 36 (34.3%) reaching the endpoint displayed significantly reduced RA strain parameters. At Kaplan-Meier analysis, impaired RA reservoir (RARS) and booster strains (RABS) were associated with an increased risk of the endpoint. After adjusting for conventional risk factors, RARS (hazard ratio [HR], 0.956; p = 0.005) and RABS (HR, 0.906; p = 0.002) resulted as independent predictors for endpoint at Cox regression analyses. In addition, RARS and RABS improved prognostic value to clinical risk factors and CMR morphological and functional predictors (all p < 0.05).

CONCLUSION

RARS and RABS were independent predictors for adverse cardiac events, which could provide incremental prognostic value for conventional predictors in ARVC.

CRITICAL RELEVANCE STATEMENT

We evaluated the prognostic value of right atrial strain in ARVC patients and suggested cardiologists consider RA strain as a predictive parameter when evaluating the long-term outcome of ARVC patients in order to formulate better clinical therapy.

KEY POINTS

• Patients with ARVC had significantly reduced RA strain and strain rates compared with healthy participants. • Participants with lower RA reservoir and booster stains were associated with a significantly higher risk of adverse cardiac events. • RA booster and reservoir strain provide incremental value to conventional parameters.

Incremental Diagnostic Value of Right Ventricular Strain Analysis in Arrhythmogenic Right Ventricular Cardiomyopathy

BACKGROUND

Strain analysis is a sensitive method for the assessment of ventricular structural or functional alterations. The authors aimed to determine whether right ventricular (RV) strain parameters can discriminate patients with revised Task Force Criteria-diagnosed arrhythmogenic RV cardiomyopathy (ARVC) incremental to the existing cardiovascular magnetic resonance (CMR) criteria, thus improving the diagnostic yield of CMR in ARVC.

METHODS AND RESULTS

A total of 74 patients with revised Task Force Criteria-diagnosed ARVC (37 borderline and 37 definite) and 37 controls were retrospectively enrolled for analysis. Using CMR feature tracking, RV global longitudinal (GLS), circumferential, and radial strain of all participants were evaluated. Compared with controls, the study patients demonstrated significantly impaired global biventricular strain in all 3 directions (all P<0.001). Receiver operating characteristic curve analysis indicated that RV GLS was the strongest discriminator among all RV strain parameters for the identification of patients with ARVC (area under the curve, 0.92). Using the Youden index, the authors determined RV GLS ≥-19.95% as the diagnostic criterion of ARVC. In patients diagnosed with borderline ARVC according to revised Task Force Criteria but with no or only minor CMR criteria, there were >50% presenting with impaired RV GLS. When both conventional criteria and RV GLS were considered together, this new diagnostic method demonstrated an overall diagnostic accuracy of 90%. The likelihood ratio test showed a significant incremental diagnostic value of RV GLS (P=0.02) over the existing CMR major criteria.

CONCLUSIONS

The current study showed an improved diagnostic accuracy when both RV GLS and the existing CMR criteria were considered together, especially for patients with borderline diagnosis, suggesting the incremental value of strain analysis to the initial assessment of ARVC.

The year 2022 in the European Heart Journal-Cardiovascular Imaging: Part I

The European Heart Journal-Cardiovascular Imaging with its over 10 years existence is an established leading multi-modality cardiovascular imaging journal. Pertinent publications including original research, how-to papers, reviews, consensus documents, and in our journal from 2022 have been highlighted in two reports. Part I focuses on cardiomyopathies, heart failure, valvular heart disease, and congenital heart disease and related emerging techniques and technologies.

Arrhythmic risk stratification in arrhythmogenic right ventricular cardiomyopathy

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a heritable cardiomyopathy characterized by a predominantly arrhythmic presentation. It represents the leading cause of sudden cardiac death (SCD) among athletes and poses a significant morbidity threat in the general population. As a causative treatment for ARVC is still not available, the placement of an implantable cardioverter defibrillator represents the current cornerstone for SCD prevention in this setting. Thanks to international ARVC-dedicated efforts, significant steps have been achieved in recent years towards an individualized, patient-centred risk stratification approach. A novel risk calculator algorithm estimating the 5-year risk of arrhythmias of patients with ARVC has been introduced in clinical practice and subsequently validated. The purpose of this article is to summarize the body of evidence that has allowed the development of this tool and to discuss the best way to implement its use in the care of an individual patient.

Value of cardiac magnetic resonance on the risk stratification of cardiomyopathies

Cardiomyopathies represent a diverse group of heart muscle diseases with varying etiologies, presenting a diagnostic challenge due to their heterogeneous manifestations. Regular evaluation using cardiac imaging techniques is imperative as symptoms can evolve over time. These imaging approaches are pivotal for accurate diagnosis, treatment planning, and optimizing prognostic outcomes. Among these, cardiovascular magnetic resonance (CMR) stands out for its ability to provide precise anatomical and functional assessments. This manuscript explores the significant contributions of CMR in the diagnosis and management of patients with cardiomyopathies, with special attention to risk stratification. CMR's high spatial resolution and tissue characterization capabilities enable early detection and differentiation of various cardiomyopathy subtypes. Additionally, it offers valuable insights into myocardial fibrosis, tissue viability, and left ventricular function, crucial parameters for risk stratification and predicting adverse cardiac events. By integrating CMR into clinical practice, clinicians can tailor patient-specific treatment plans, implement timely interventions, and optimize long-term prognosis. The non-invasive nature of CMR reduces the need for invasive procedures, minimizing patient discomfort. This review highlights the vital role of CMR in monitoring disease progression, guiding treatment decisions, and identifying potential complications in patients with cardiomyopathies. The utilization of CMR has significantly advanced our understanding and management of these complex cardiac conditions, leading to improved patient outcomes and a more personalized approach to care.

Prevention of Sudden Death and Management of Ventricular Arrhythmias in Arrhythmogenic Cardiomyopathy

Arrhythmogenic cardiomyopathy is an umbrella term for a group of inherited diseases of the cardiac muscle characterized by progressive fibro-fatty replacement of the myocardium. As suggested by the name, the disease confers electrical instability to the heart and increases the risk of the development of life-threatening arrhythmias, representing one of the leading causes of sudden cardiac death (SCD), especially in young athletes. In this review, the authors review the current knowledge of the disease, highlighting the state-of-the-art approaches to the prevention of the occurrence of SCD.

Assessment of Right Ventricle Function and Tricuspid Regurgitation in Heart Failure: Current Advances in Diagnosis and Imaging

Right ventricular (RV) systolic dysfunction increases mortality among heart failure patients, and therefore, accurate diagnosis and monitoring is paramount. RV anatomy and function are complex, usually requiring a combination of imaging modalities to completely quantitate volumes and function. Tricuspid regurgitation usually occurs with RV dysfunction, and quantifying this valvular lesion also may require multiple imaging modalities. Echocardiography is the first-line imaging tool for identifying RV dysfunction, with cardiac MRI and cardiac computed tomography adding valuable additional information.

Radial and Circumferential CMR-Based RV Strain Predicts Low R Wave Amplitude after ICD Implantation in Patients with Arrhythmogenic Cardiomyopathy

Inadequate R wave amplitude (RWA) after implantable cardiac defibrillator (ICD) implantation in patients with arrhythmogenic cardiomyopathy (ACM) was suspected to relate to right ventricle impairment. However, little data-based evidence was provided to quantify the association. We retrospectively enrolled ACM patients receiving CMR examinations before transvenous ICD implantation from Fuwai Hospital. The RWA was obtained within 24 h and at 2-6-month follow-up after the operation. Structural, functional, as well as tissue characterization of the left ventricle (LV) and right ventricle (RV), were analyzed in relation to RWA. Among the 87 ACM patients (median RWA: 8.0 mV), 19 (21.8%) patients were found with low initial RWA (<5 mV) despite attempts in multiple positions. RV end diastolic diameter (RVEDD), (r = -0.44), RV ejection fraction (RVEF, r = 0.43), RV end diastolic volume index (RVEDVi, r = -0.49), RV end systolic volume index (RVESVi, r = -0.53), RV global circumferential (RVGCS, r = -0.64), and radial strain (RVGRS, r = 0.61, all p < 0.001) rather than LV metrics correlated strongly with initial RWA. RVGCS, RVESVi, and RVGRS were decent predictors of low RWA (areas under the curve AUC: 0.814, 0.769, 0.757, respectively) early after implantation and during 2-6-month follow-up. To summarize, low RWA of ICD lead in ACM patients was associated with RV abnormalities. The RVGCS, RVGRS, and RVESVi can be valuable predictors for identifying low RWA prior to ICD implantation.

ECG-based techniques to enhance clinical practice in cardiac genetic disease management

INTRODUCTION

Inherited cardiomyopathies are associated with a broad spectrum of potentially lethal phenotypes characterized by structural and electrical myocardial remodeling. Increased awareness and genetic cascade screening lead to more genotype-positive, yet phenotype-negative individuals to be evaluated and followed up. The predictive value of genetic testing is hampered by incomplete penetrance and high variability in disease onset, progression and severity.

CLINICAL CHALLENGES

Dilated cardiomyopathy usually manifests with symptoms of heart failure and ventricular arrhythmias (VA) develop in advanced disease. In arrhythmogenic cardiomyopathy (ACM), electrical remodeling can precede structural and functional changes and life-threatening VA can be the first disease manifestation. Early signs and symptoms may be subtle and go unnoticed. Physicians are in great need of appropriate screening and risk-stratification strategies. Task Force Criteria (TFC) were established to standardize the clinical diagnosis of ACM but risk-stratification remains challenging. Accurate prediction of disease progression in variation carriers is currently beyond the capabilities of diagnostic tests.

PROPOSED DIAGNOSTIC TECHNIQUES

We propose three ECG-based techniques; isopotential mapping, inverse ECG and CineECG, to enhance risk-stratification in ACM. With the use of isopotential mapping abnormal spatio-temporal activation and repolarization may be identified. Furthermore, by combining subject specific ≥12‑lead ECG data with cardiothoracic imaging using inverse ECG techniques, the direct link between ECG and cardiac anatomy can be obtained.

CONCLUSION

New ECG techniques may prove more sensitive to detect early de- and repolarization abnormalities in yet asymptomatic variation carriers. Early electrical signs of disease progression may be identified prior to symptoms. Furthermore, individualized risk-stratification may be enhanced.

Right Ventricular Strain by Magnetic Resonance Feature Tracking Is Largely Afterload-Dependent and Does Not Reflect Contractility: Validation by Combined Volumetry and Invasive Pressure Tracings

Cardiac magnetic resonance (CMR) is currently the gold standard for evaluating right ventricular (RV) function, which is critical in patients with pulmonary hypertension. CMR feature-tracking (FT) strain analysis has emerged as a technique to detect subtle changes. However, the dependence of RV strain on load is still a matter of debate. The aim of this study was to measure the afterload dependence of RV strain and to correlate it with surrogate markers of contractility in a cohort of patients with chronic thromboembolic pulmonary hypertension (CTEPH) under two different loading conditions before and after pulmonary endarterectomy (PEA). Between 2009 and 2022, 496 patients with 601 CMR examinations were retrospectively identified from our CTEPH cohort, and the results of 194 examinations with right heart catheterization within 24 h were available. The CMR FT strain (longitudinal (GLS) and circumferential (GCS)) was computed on steady-state free precession (SSFP) cine CMR sequences. The effective pulmonary arterial elastance (Ea) and RV chamber elastance (Ees) were approximated by dividing mean pulmonary arterial pressure by the indexed stroke volume or end-systolic volume, respectively. GLS and GCS correlated significantly with Ea and Ees/Ea in the overall cohort and individually before and after PEA. There was no general correlation with Ees; however, under high afterload, before PEA, Ees correlated significantly. The results show that RV GLS and GCS are highly afterload-dependent and reflect ventriculoarterial coupling. Ees was significantly correlated with strain only under high loading conditions, which probably reflects contractile adaptation to pulsatile load rather than contractility in general.

Longitudinal Prediction of Ventricular Arrhythmic Risk in Patients With Arrhythmogenic Right Ventricular Cardiomyopathy

BACKGROUND

The arrhythmogenic right ventricular cardiomyopathy (ARVC) risk calculator stratifies risk for incident sustained ventricular arrhythmias (VA) at the time of ARVC diagnosis. However, included risk factors change over time, and how well the ARVC risk calculator performs at follow-up is unknown.

METHODS

This was a retrospective analysis of patients with definite ARVC and without prior sustained VA. Risk factors for VA including age, nonsustained ventricular tachycardia, premature ventricular complex burden, T-wave inversions on electrocardiogram, cardiac syncope, right ventricular function, therapeutic medication use, and exercise intensity were assessed at the time of 2010 Task Force Criteria based ARVC diagnosis and upon repeat evaluations. Changes in these risk factors were analyzed over 5-year follow-up. The 5-year risk of VA was predicted longitudinally using (1) the baseline ARVC risk calculator prediction, (2) the ARVC risk prediction calculated using updated risk factors, and (3) time-varying Cox regression. Discrimination and calibration were assessed in comparison to observed VA event rates.

RESULTS

Four hundred eight patients with ARVC experiencing 132 primary VA events were included. Matched comparison of risk factors at baseline versus at 5 years of follow-up revealed decreased burdens of premature ventricular complexes (-1200/day) and nonsustained ventricular tachycardia (-14%). Presence of significant right ventricular dysfunction and number of T-wave inversions on electrocardiogram were unchanged. Observed risk for VA decreased by 13% by 5 years follow-up. The baseline ARVC risk calculator's ability to predict 5-year VA risk worsened during follow-up (C statistics, 0.83 at diagnosis versus 0.68 at 5 years). Both the updated ARVC risk calculator (C statistics of 0.77) and time-varying Cox regression model (C statistics, 0.77) had strong discrimination. The updated ARVC risk calculator overestimated 5-year VA risk by an average of +6%.

CONCLUSIONS

Risk factors for VA in ARVC are dynamic, and overall risk for incident sustained VA decreases during follow-up. Up-to-date risk factor assessment improves VA risk stratification.