Impact of the presence and amount of myocardial fibrosis by cardiac magnetic resonance on arrhythmic outcome and sudden cardiac death in nonischemic dilated cardiomyopathy

Clinical impact of long PR-interval and presence of late gadolinium enhancement on hospitalized patients with non-ischemic heart failure

BACKGROUND

The combination of electrical and structural remodeling may have a strong effect on the prognosis of non-ischemic heart failure (HF). We aimed to clarify whether prolonged PR-interval and the presence of late gadolinium enhancement (LGE) on cardiac magnetic resonance imaging (CMR) influence the outcomes of patients with non-ischemic HF.

METHODS

We studied 262 consecutive hospitalized patients with non-ischemic HF. In a clinically stable condition, a 12-lead electrocardiogram and CMR were performed, and the clinical characteristics and outcomes were investigated.

RESULTS

During the follow-up of 967.7 ± 851.8 days, there were 68 (25.9%) cardiac events (HF or sudden death, re-hospitalization due to HF, or ventricular tachyarrhythmias). In a multivariable analysis, a median rate-adjusted PR (PRa)-interval of ≥173.5 ms and the presence of LGE were associated with cardiac events with a hazard ratio of 1.690 and 2.045 (p = .044 and p = .006, respectively). Study subjects were then divided into four groups based on long (≥173.5 ms) or short (<173.5 ms) PRa-interval and LGE status: short PRa/non-LGE (n = 80), long PRa/non-LGE (n = 72), short PRa/LGE (n = 51), and long PRa/LGE (n = 59). Cardiac events were 16.2% in short PRa/non-LGE, 25.0% in long PRa/non-LGE, 27.4% in short PRa/LGE, and 38.9% in long PRa/LGE (p = .026), respectively. The multivariable Cox proportional hazard analysis showed that long PRa/LGE was an independent predictor for cardiac events compared to short PRa/non-LGE (hazard ratio, 3.378, p = .001).

CONCLUSIONS

The combination of a long PRa-interval and the presence of LGE provide a better predictive value of cardiac events in non-ischemic HF.

The Extent of Late Gadolinium Enhancement Can Predict Adverse Cardiac Outcomes in Patients with Non-Ischemic Cardiomyopathy with Reduced Left Ventricular Ejection Fraction: A Prospective Observational Study

OBJECTIVE

The clinical course of an individual patient with heart failure is unpredictable with left ventricle ejection fraction (LVEF) only. We aimed to evaluate the prognostic value of cardiac magnetic resonance (CMR)-derived myocardial fibrosis extent and to determine the cutoff value for event-free survival in patients with non-ischemic cardiomyopathy (NICM) who had severely reduced LVEF.

MATERIALS AND METHODS

Our prospective cohort study included 78 NICM patients with significantly reduced LV systolic function (LVEF < 35%). CMR images were analyzed for the presence and extent of late gadolinium enhancement (LGE). The primary outcome was major adverse cardiac events (MACEs), defined as a composite of cardiac death, heart transplantation, implantable cardioverter-defibrillator discharge for major arrhythmia, and hospitalization for congestive heart failure within 5 years after enrollment.

RESULTS

A total of 80.8% (n = 63) of enrolled patients had LGE, with the median LVEF of 25.4% (19.8-32.4%). The extent of myocardial scarring was significantly higher in patients who experienced MACE than in those without any cardiac events (22.0 [5.5-46.1] %LV vs. 6.7 [0-17.1] %LV, respectively, p = 0.008). During follow-up, 51.4% of patients with LGE ≥ 12.0 %LV experienced MACE, along with 20.9% of those with LGE ≤ 12.0 %LV (log-rank p = 0.001). According to multivariate analysis, LGE extent more than 12.0 %LV was independently associated with MACE (adjusted hazard ratio, 6.71; 95% confidence interval, 2.54-17.74; p < 0.001).

CONCLUSION

In NICM patients with significantly reduced LV systolic function, the extent of LGE is a strong predictor for long-term adverse cardiac outcomes. Event-free survival was well discriminated with an LGE cutoff value of 12.0 %LV in these patients.

Presence of fragmented QRS is associated with left ventricular systolic dysfunction after surgery in patients with severe aortic regurgitation

BACKGROUND AND AIM OF THE STUDY

Chronic severe aortic regurgitation (AR) is associated with progressive accumulation of interstitial fibrosis and disruption of myocardial structure. After aortic valve replacement (AVR), the negative remodeling process reverses, and left ventricular ejection fraction (LVEF) improves but not in all patients. In this study, we aimed to investigate the association of fragmented QRS (F-QRS), which is a possible marker of myocardial fibrosis, with postoperative left ventricular (LV) systolic dysfunction.

METHODS

A total of 147 consecutive patients with AVR were included in this study. F-QRS was identified by the presence of various RSR' patterns (QRS duration <120 ms) such as additional R wave (R prime)or notching of the R or S wave in at least two consecutive leads. Patients were compared in two groups based on the presence or absence of F-QRS. A logistic regression model was used to determine independent predictors of postoperative LV systolic dysfunction (LVEF <50%).

RESULTS

Patients with F-QRS were associated with poor recovery of LV systolic function after AVR compared to the patients without F-QRS, regardless of preoperative LVEF (p = .008). F-QRS was found to be an independent predictor of postoperative LV systolic dysfunction (LVEF <50%). Lower preoperative LVEF and increased LV end diastolic diameter index were also found as independent risk factors for postoperative LV systolic dysfunction.

CONCLUSIONS

As a possible marker of myocardial fibrosis, F-QRS was associated with postoperative LV systolic dysfunction. Therefore, as a simple and convenient clinical parameter, F-QRS may be used to predict poor recovery of LVEF after AVR.

Progression of Myocardial Fibrosis in Nonischemic DCM and Association With Mortality and Heart Failure Outcomes

OBJECTIVES

The purpose of this study was to assess whether the presence and extent of fibrosis changes over time in patients with nonischemic, dilated cardiomyopathy (DCM) receiving optimal medical therapy and the implications of any such changes on left ventricular ejection fraction (LVEF) and clinical outcomes.

BACKGROUND

Myocardial fibrosis on cardiovascular magnetic resonance (CMR) imaging has emerged as important risk marker in patients with DCM.

METHODS

In total, 85 patients (age 56 ± 15 years, 45% women) with DCM underwent serial CMR (median interval 1.5 years) for assessment of LVEF and fibrosis. The primary outcome was all-cause mortality; the secondary outcome was a composite of heart failure hospitalization, aborted sudden cardiac death, left ventricular (LV) assist device implantation, or heart transplant.

RESULTS

On CMR-1, fibrosis (median 0.0 [interquartile range: 0% to 2.6%]) of LV mass was noted in 34 (40%) patients. On CMR-2, regression of fibrosis was not seen in any patient. Fibrosis findings were stable in 70 (82%) patients. Fibrosis progression (increase >1.8% of LV mass or new fibrosis) was seen in 15 patients (18%); 46% of these patients had no fibrosis on CMR-1. Although fibrosis progression was on aggregate associated with adverse LV remodeling and decreasing LVEF (40 ± 7% to 34 ± 10%; p < 0.01), in 60% of these cases the change in LVEF was minimal (<5%). Fibrosis progression was associated with increased hazards for all-cause mortality (hazard ratio: 3.4 [95% confidence interval: 1.5 to 7.9]; p < 0.01) and heart failure-related complications (hazard ratio: 3.5 [95% confidence interval: 1.5 to 8.1]; p < 0.01) after adjustment for clinical covariates including LVEF.

CONCLUSIONS

Once myocardial replacement fibrosis in DCM is present on CMR, it does not regress in size or resolve over time. Progressive fibrosis is often associated with minimal change in LVEF and identifies a high-risk cohort.

2019 HRS/EHRA/APHRS/LAHRS expert consensus statement on catheter ablation of ventricular arrhythmias

Ventricular arrhythmias are an important cause of morbidity and mortality and come in a variety of forms, from single premature ventricular complexes to sustained ventricular tachycardia and fibrillation. Rapid developments have taken place over the past decade in our understanding of these arrhythmias and in our ability to diagnose and treat them. The field of catheter ablation has progressed with the development of new methods and tools, and with the publication of large clinical trials. Therefore, global cardiac electrophysiology professional societies undertook to outline recommendations and best practices for these procedures in a document that will update and replace the 2009 EHRA/HRS Expert Consensus on Catheter Ablation of Ventricular Arrhythmias. An expert writing group, after reviewing and discussing the literature, including a systematic review and meta-analysis published in conjunction with this document, and drawing on their own experience, drafted and voted on recommendations and summarized current knowledge and practice in the field. Each recommendation is presented in knowledge byte format and is accompanied by supportive text and references. Further sections provide a practical synopsis of the various techniques and of the specific ventricular arrhythmia sites and substrates encountered in the electrophysiology lab. The purpose of this document is to help electrophysiologists around the world to appropriately select patients for catheter ablation, to perform procedures in a safe and efficacious manner, and to provide follow-up and adjunctive care in order to obtain the best possible outcomes for patients with ventricular arrhythmias.

Current challenges in sudden cardiac death prevention

Ischemic heart disease and non-ischemic dilated cardiomyopathy are the most common causes of arrhythmic sudden cardiac death (SCD). Implantable cardioverter defibrillator (ICD) therapy is the only strategy that proved to be effective in preventing SCD in high-risk individuals while the role of antiarrhythmic drugs is limited to symptoms relief. Current guidelines recommend selecting candidates to ICD implantation based on etiology, symptoms of heart failure (NYHA class), and severely depressed left ventricular ejection fraction, but these parameters are neither sensitive nor specific. The review addresses the mechanisms of SCD in patients with heart failure of either ischemic or non-ischemic etiology, risk stratification, and strategies for prevention of SCD in the clinical practice (including optimization of heart failure therapy, avoidance of triggering factors, antiarrhythmic drugs, ICD therapy, early resuscitation, and public access defibrillators).

Friedreich's Ataxia: Case series and the Additive Value of Cardiovascular Magnetic Resonance

BackgroundFriedreich's ataxia (FA) is an autosomal-recessive neurodegenerative disease characterised by neurologic, cardiac and endocrine abnormalities. Currently, Friedreich cardiomyopathy (FA-CM) staging is based on early ECG findings, high sensitivity troponin (hsTNT) ≥14 ng/ml and echocardiographic left ventricular (LV) morphologic and functional evaluation. However, further parameters, accessible only by cardiovascular magnetic resonance (CMR), such as myocardial oedema, perfusion defects, replacement and/or diffuse myocardial fibrosis, may have a place in the staging of FA-CA. Our aim was to elucidate the additive value of CMR in FA-CM.MethodsThree FA cases were assessed using ECG, 24 h Holter recording, hsTNT, routine ECHO including wall dimension, valvular and ventricular function evaluation and CMR using 1.5T Ingenia system. Ventricular volumes-function, wall dimensions and fibrosis imaging using late gadolinium enhancement (LGE) was performed.ResultsAll FA patients had non-specific ECG changes, almost normal 24 h Holter recording, mild hypertrophy with normal function assessed by echocardiography and increased hsTNT. However, the CMR evaluation revealed the presence of LGE >5% of LV mass, indicative of severe fibrosis. Therefore, the FA patients were re-categorized as having severe FA-CA, although their LVEF remained normal.ConclusionThe combination of classical diagnostic indices and CMR may reveal early asymptomatic FA-CM and motivate the early initiation of cardiac treatment. Furthermore, these indices can be also used to validate specific treatment targets in FA, potentially useful in the prevention of FA-CM.

2019 HRS/EHRA/APHRS/LAHRS expert consensus statement on catheter ablation of ventricular arrhythmias

Ventricular arrhythmias are an important cause of morbidity and mortality and come in a variety of forms, from single premature ventricular complexes to sustained ventricular tachycardia and fibrillation. Rapid developments have taken place over the past decade in our understanding of these arrhythmias and in our ability to diagnose and treat them. The field of catheter ablation has progressed with the development of new methods and tools, and with the publication of large clinical trials. Therefore, global cardiac electrophysiology professional societies undertook to outline recommendations and best practices for these procedures in a document that will update and replace the 2009 EHRA/HRS Expert Consensus on Catheter Ablation of Ventricular Arrhythmias. An expert writing group, after reviewing and discussing the literature, including a systematic review and meta-analysis published in conjunction with this document, and drawing on their own experience, drafted and voted on recommendations and summarized current knowledge and practice in the field. Each recommendation is presented in knowledge byte format and is accompanied by supportive text and references. Further sections provide a practical synopsis of the various techniques and of the specific ventricular arrhythmia sites and substrates encountered in the electrophysiology lab. The purpose of this document is to help electrophysiologists around the world to appropriately select patients for catheter ablation, to perform procedures in a safe and efficacious manner, and to provide follow-up and adjunctive care in order to obtain the best possible outcomes for patients with ventricular arrhythmias.

Management of nonischemic-dilated cardiomyopathies in clinical practice: a position paper of the working group on myocardial and pericardial diseases of Italian Society of Cardiology

: Nonischemic-dilated cardiomyopathy (NIDCM) is an entity that gathers extremely heterogeneous diseases. This awareness, although leading to continuous improvement in survival, has increased the complexity of NIDCM patients' management. Even though the endorsed 'red-flags' approach helps clinicians in pursuing an accurate etiological definition in clinical practice, it is not clear when and how peripheral centers should interact with referral centers with specific expertise in challenging scenarios (e.g. postmyocarditis and genetically determined dilated cardiomyopathy) and with easier access to second-line diagnostic tools and therapies. This position paper will summarize each step in NIDCM management, highlighting the multiple interactions between peripheral and referral centers, from first-line diagnostic workup and therapy to advanced heart failure management and long-term follow-up.

Updating the Risk Stratification for Sudden Cardiac Death in Cardiomyopathies: The Evolving Role of Cardiac Magnetic Resonance Imaging. An Approach for the Electrophysiologist

The prevention of sudden cardiac death (SCD) in cardiomyopathies (CM) remains a challenge. The current guidelines still favor the implantation of devices for the primary prevention of SCD only in patients with severely reduced left ventricular ejection fraction (LVEF) and heart failure (HF) symptoms. The implantation of an implantable cardioverter-defibrillator (ICD) is a protective barrier against arrhythmic events in CMs, but the benefit does not outweigh the cost in low risk patients. The identification of high risk patients is the key to an individualized prevention strategy. Cardiac magnetic resonance (CMR) provides reliable and reproducible information about biventricular function and tissue characterization. Furthermore, late gadolinium enhancement (LGE) quantification and pattern of distribution, as well as abnormal T1 mapping and extracellular volume (ECV), representing indices of diffuse fibrosis, can enhance our ability to detect high risk patients. CMR can also complement electro-anatomical mapping (EAM), a technique already applied in the risk evaluation and in the ventricular arrhythmias ablation therapy of CM patients, providing a more accurate assessment of fibrosis and arrhythmic corridors. As a result, CMR provides a new insight into the pathological substrate of CM. CMR may help identify high risk CM patients and, combined with EAM, can provide an integrated evaluation of scar and arrhythmic corridors in the ablative therapy of ventricular arrhythmias.

Multimodality imaging assessment of mitral annular disjunction in mitral valve prolapse

OBJECTIVE

Mitral annular disjunction (MAD) is an abnormality linked to mitral valve prolapse (MVP), possibly associated with malignant ventricular arrhythmias. We assessed the agreement among different imaging techniques for MAD identification and measurement.

METHODS

131 patients with MVP and significant mitral regurgitation undergoing transthoracic echocardiography (TTE) and cardiac magnetic resonance (CMR) were retrospectively enrolled. Transoesophageal echocardiography (TOE) was available in 106 patients. MAD was evaluated in standard long-axis views (four-chamber, two-chamber, three-chamber) by each technique.

RESULTS

Considering any-length MAD, MAD prevalence was 17.3%, 25.5%, 42.0% by TTE, TOE and CMR, respectively (p<0.05). The agreement on MAD identification was moderate between TTE and CMR (κ=0.54, 95% CI 0.49 to 0.59) and good between TOE and CMR (κ=0.79, 95% CI 0.74 to 0.84). Assuming CMR as reference and according to different cut-off values for MAD (≥2 mm, ≥4 mm, ≥6 mm), specificity (95% CI) of TTE and TOE was 99.6 (99.0 to 100.0)% and 98.7 (97.4 to 100.0)%; 99.3 (98.4 to 100.0)% and 97.6 (95.8 to 99.4)%; 97.8 (96.2 to 99.3)% and 93.2 (90.3 to 96.1)%, respectively; sensitivity (95% CI) was 43.1 (37.8 to 48.4)% and 74.5 (69.4 to 79.5)%; 54.0 (48.7 to 59.3)% and 88.9 (85.2 to 92.5)%; 88.0 (84.5 to 91.5)% and 100.0 (100.0 to 100.0)%, respectively. MAD length was 8.0 (7.0-10.0), 7.0 (5.0-8.0], 5.0 (4.0-7.0) mm, respectively by TTE, TOE and CMR. Agreement on MAD measurement was moderate between TTE and CMR (ρ=0.73) and strong between TOE and CMR (ρ=0.86).

CONCLUSIONS

An integrated imaging approach could be necessary for a comprehensive assessment of patients with MVP and symptoms suggestive for arrhythmias. If echocardiography is fundamental for the anatomic and haemodynamic characterisation of the MV disease, CMR may better identify small length MAD as well as myocardial fibrosis.

Differential diagnosis of arrhythmogenic cardiomyopathy: phenocopies versus disease variants

Arrhythmogenic cardiomyopathy (ACM) is a genetic heart muscle disease caused by mutations of desmosomal genes in about 50% of patients. Affected patients may have defective non-desmosomal genes. The ACM phenotype may occur in other genetic cardiomyopathies, cardio-cutaneous syndromes or neuromuscular disorders. A sizeable proportion of patients have non-genetic diseases with clinical features resembling ACM (phenocopies). The identification of biventricular and left-dominant phenotypic variants has made differential diagnosis more difficult because of the broader spectrum of phenocopies which requires a detailed clinical study with appropriate evaluation of most prominent and discriminatory disease features. Conditions that enter into differential diagnosis of ACM include heart muscle diseases affecting the right ventricle, the left ventricle, or both. To confirm a conclusive diagnosis of ACM, these differential possibilities need to be reasonably excluded by an accurate and targeted clinical evaluation. This article reviews the clinical and imaging features of major phenocopies of ACM and provides indications for differential diagnosis. The recent etiologic classification of Arrhythmogenic Cardiomyopathies, whose common denominator is the distinctive phenotype characterized by a hypokinetic and non-dilated ventricle with a large amount of myocardial fibrosis underlying its propensity to generate ventricular arrhythmias is also addressed.

Structural and Physiological Imaging to Predict the Risk of Lethal Ventricular Arrhythmias and Sudden Death

Identifying patients at risk of sudden cardiac death remains a major challenge in cardiovascular medicine. Advances in cardiovascular imaging have identified several anatomic and functional variables that can be quantified as continuous variables to predict the risk of developing lethal ventricular tachyarrhythmias in patients with depressed left ventricular (LV) systolic function. Some, such as LV mass, volume, and the dyssynchrony of contraction, can be derived from currently available echocardiographic and nuclear imaging modalities. Others require advanced cardiac imaging modalities with quantification of myocardial scar with gadolinium-enhanced cardiac magnetic resonance and myocardial sympathetic denervation using norepinephrine analogs and positron emission tomography or single-photon emission computed tomography offering the most promise. There is an immediate need to develop a sequential cost-effective approach that capitalizes on readily available clinical information complemented with advanced imaging modalities in selected patients to improve risk stratification for arrhythmic death beyond LV ejection fraction.

Multi-Modality Imaging in Dilated Cardiomyopathy: With a Focus on the Role of Cardiac Magnetic Resonance

Heart failure (HF) is recognized as a leading cause of morbidity and mortality worldwide. Dilated cardiomyopathy (DCM) is a common phenotype in patients presenting with HF. Timely diagnosis, appropriate identification of the underlying cause, individualized risk stratification, and prediction of clinical response to treatment have improved the prognosis of DCM over the last few decades. In this article, we reviewed the current evidence on available imaging techniques used for DCM patients. In this direction, we evaluated appropriate scenarios for the implementation of echocardiography, nuclear imaging, and cardiac computed tomography, and we focused on the primordial role that cardiac magnetic resonance (CMR) holds in the diagnosis, prognosis, and tailoring of therapeutic options in this population of special clinical interest. We explored the predictive value of CMR toward left ventricular reverse remodeling and prediction of sudden cardiac death, thus guiding the decisions for device therapy. Principles underpinning the use of state-of-the-art CMR techniques such as parametric mapping and feature-tracking strain analysis are also provided, along with expectations for the anticipated future advances in this field. We also attempted to correlate the evidence with clinical practice, with the intent to address questions on selecting the optimal imaging method for different indications and clinical needs. Overall, we recommend a comprehensive assessment of DCM patients at baseline and at follow-up intervals depending on the clinical status, with the addition of CMR as a second-line modality to other imaging techniques. We also provide an algorithm to guide the detailed imaging approach of the patient with DCM. We expect that future guidelines will upgrade their clinical recommendations for the utilization of CMR in DCM, which is expected to further improve the quality of care and the outcomes. This review provides an up-to-date perspective on the imaging of dilated cardiomyopathy patients and will be of clinical value to training doctors and physicians involved in the area of heart failure.

Early Detection of Myocardial Damage: A Multimodality Approach

Cardiovascular diseases are possible complications of antineoplastic treatment and may lead to premature morbidity and mortality among cancer survivors. A symptom-based follow-up is ineffective, and there are growing evidences that early detection of myocardial damage in patients treated with antineoplastic drugs is the key point to prevent the occurrence of damage and improve the prognosis of these patients. Different techniques have been proposed to monitor cardiac function in oncologic patients such as cardiac imaging (echocardiography, nuclear imaging, and cardiac magnetic resonance) and biomarkers (troponin and natriuretic peptides). The European Association of Cardiovascular Imaging/American Society of Echocardiography consensus document encourages an integrated approach to early detect cardiotoxicity.

Non-ischemic compared to ischemic cardiomyopathy is associated with increasing recurrent ventricular tachyarrhythmias and ICD-related therapies

OBJECTIVE

The study sought to assess the impact of ischemic (ICMP) compared to non-ischemic cardiomyopathy (NICMP) on recurrences of ventricular tachyarrhythmias in implantable cardioverter defibrillator (ICD) recipients.

BACKGROUND

Data comparing recurrences of ventricular tachyarrhythmias in ICD recipients with ischemic or non-ischemic cardiomyopathy is limited.

METHODS

A large retrospective registry was used including all consecutive ICD recipients with first episodes of ventricular tachycardia (VT) or fibrillation (VF) from 2002 to 2016. Patients with ICMP were compared to patients with NICMP. The primary prognostic endpoint was first recurrences of ventricular tachyarrhythmias at one year. Secondary endpoints comprised ICD-related therapies, rehospitalization and all-cause mortality at one year. Statistics Kaplan-Meier survival and multivariable Cox regression analyses.

RESULTS

A total of 387 consecutive ICD recipients were included retrospectively (ICMP: 82%, NICMP: 18%). At one year of follow-up, freedom from first recurrences of ventricular tachyarrhythmias was lower in NICMP (81% vs. 71%, log-rank p = 0.063; HR = 1.760; 95% CI 0.985-3.002; p = 0.080), mainly attributed to higher rates of sustained VT (20% versus 12%, p = 0.054). Accordingly, freedom from first appropriate device therapies was lower in NICMP (74% vs. 85%, log rank p = 0.004; HR = 1.951; 95% CI 1.121-3.397; p = 0.028), especially in patients with sustained VT or VF at index. Both groups revealed comparable rates of rehospitalization and all-cause mortality at one year.

CONCLUSION

NICMP was associated with higher rates of recurrent ventricular tachyarrhythmias and appropriate ICD therapies compared to ICMP at one year of follow-up, whereas rates of rehospitalization and all-cause mortality were comparable.

CONDENSED ABSTRACT

This study retrospectively compared the impact of cardiomyopathy types (ICMP versus NICMP) on recurrences of ventricular tachyarrhythmias in 387 ICD recipients. Freedom from first episodes of ventricular tachyarrhythmias and first appropriate device therapies were lower in patients with NICMP compared to ICMP.

Arrhythmogenic Right Ventricular Cardiomyopathy: Characterization of Left Ventricular Phenotype and Differential Diagnosis With Dilated Cardiomyopathy

Background

This study assessed the prevalence of left ventricular (LV) involvement and characterized the clinical, electrocardiographic, and imaging features of LV phenotype in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC). Differential diagnosis between ARVC‐LV phenotype and dilated cardiomyopathy (DCM) was evaluated.

Methods and Results

The study population included 87 ARVC patients (median age 34 years) and 153 DCM patients (median age 51 years). All underwent cardiac magnetic resonance with quantitative tissue characterization. Fifty‐eight ARVC patients (67%) had LV involvement, with both LV systolic dysfunction and LV late gadolinium enhancement (LGE) in 41/58 (71%) and LV‐LGE in isolation in 17 (29%). Compared with DCM, the ARVC‐LV phenotype was statistically significantly more often characterized by low QRS voltages in limb leads, T‐wave inversion in the inferolateral leads and major ventricular arrhythmias. LV‐LGE was found in all ARVC patients with LV systolic dysfunction and in 69/153 (45%) of DCM patients. Patients with ARVC and LV systolic dysfunction had a greater amount of LV‐LGE (25% versus 13% of LV mass; P<0.01), mostly localized in the subepicardial LV wall layers. An LV‐LGE ≥20% had a 100% specificity for diagnosis of ARVC‐LV phenotype. An inverse correlation between LV ejection fraction and LV‐LGE extent was found in the ARVC‐LV phenotype (r=−0.63; P<0.01), but not in DCM (r=−0.01; P=0.94).

Conclusions

LV involvement in ARVC is common and characterized by clinical and cardiac magnetic resonance features which differ from those seen in DCM. The most distinctive feature of ARVC‐LV phenotype is the large amount of LV‐LGE/fibrosis, which impacts directly and negatively on the LV systolic function.

The extent and location of late gadolinium enhancement predict defibrillator shock and cardiac mortality in patients with non-ischaemic dilated cardiomyopathy

BACKGROUND

In non-ischaemic dilated cardiomyopathy (NIDCM), it is uncertain which late gadolinium enhancement (LGE) pattern, extent and location predict ventricular arrhythmias.

METHODS

We analysed 183 NIDCM patients (73% men, median age 66 years) receiving an implantable cardioverter defibrillator (ICD) for primary prevention, undergoing cardiac magnetic resonance within 1 month before implantation. The primary endpoint was appropriate ICD shock, the secondary endpoint was a composite of appropriate ICD shock and cardiac death.

RESULTS

LGE was found in 116 patients (63%), accounting for 9% of LV mass (5-13%). Over a 30-month follow-up (10-65), 20 patients (11%) experienced the primary and 30 patients (16%) the secondary endpoint. LGE presence, inferior wall LGE, diffuse (≥2 wall) LGE, the number of segments with LGE, the number of segments with 50-75% transmural LGE, and percent LGE mass were univariate predictors of both endpoints. Also septal LGE predicted the primary, and lateral LGE predicted the secondary endpoint. LGE limited to right ventricular insertion points did not predict any endpoint. Percent LGE mass had an area under the curve of 0.734 for the primary endpoint, with 13% as the best cut-off (55% sensitivity, 86% specificity, 32% PPV, 94% NPV), conferring a 7-fold higher risk compared to patients with no LGE or LGE <13%. Survival free from both endpoints was significantly worse for patients with LGE ≥13%.

CONCLUSIONS

In patients with NIDCM receiving a defibrillator for primary prevention, LGE presence and extent predicted appropriate ICD shock and cardiac mortality; also specific LGE patterns and locations predicted a worse prognosis.

Echocardiographic Epicardial Adipose Tissue Thickness for Risk Stratification of Patients With Heart Failure

BACKGROUND AND AIMS

Epicardial adipose tissue (EAT) has been shown to be involved in the pathogenesis and progression of heart failure (HF). In this study we aimed to explore the predictive value of echocardiographic EAT thickness on prognosis of a selected population of HF patients.

METHODS

The patient population included n. 69 consecutive patients with systolic HF referred to implantable cardioverter defibrillator (ICD) implantation for primary or secondary prevention. At the time of enrolment, echocardiographic EAT thickness was assessed in all patients along with demographic and clinical data. The study had a median follow-up time of 49.8 months. We assessed the prognostic predictive value of EAT thickness on a composite clinical and arrhythmic outcome including HF related deaths, new hospital admissions for HF worsening, and atrial and life threatening ventricular arrhythmic events. Clinical and arrhythmic outcomes were also evaluated separately.

RESULTS

At univariate analysis, EAT thickness significantly predicted all the three outcomes considered. Of interest, at multivariate analysis, after adjusting for known risk factor, EAT remained significantly associated to the composite [HR 1.18 (1.09-1.28); p < 0.001], arrhythmic [HR 1.14 (1.03-1.25); p = 0.008], and clinical [HR 1.14 (1.03-1.27); p = 0.010] outcomes.

CONCLUSION

Echocardiographic assessment of EAT can predict outcome of HF patients and it is significantly associated with both arrhythmic and clinical events. These preliminary findings pave the way for future and larger studies aimed to definitively recognize the prognostic value of this novel risk marker in HF.

Effects of Sacubitril/Valsartan on Biomarkers of Extracellular Matrix Regulation in Patients With HFrEF

BACKGROUND

Myocardial fibrosis is an important pathophysiological mechanism underlying the development of heart failure (HF). Given the biochemical targets of sacubitril/valsartan, we hypothesized that circulating biomarkers reflecting the mechanisms that determine extracellular matrix (ECM) homeostasis, including collagen synthesis, processing, and degradation, are altered by sacubitril/valsartan in comparison to enalapril.

OBJECTIVES

The purpose of this study was to examine the effects of sacubitril/valsartan on biomarkers of ECM homeostasis and the association between the rate of primary composite outcome (cardiovascular death or HF hospitalization) and these biomarkers.

METHODS

Biomarkers at baseline (n = 2,067) and both baseline and 8 months after randomization (n = 1,776) included aldosterone, soluble ST2 (sST2), tissue inhibitor of matrix metalloproteinase (TIMP)-1, matrix metalloproteinase (MMP)-2, MMP-9, Galectin-3 (Gal-3), N-terminal propeptide of collagen I (PINP), and N-terminal propeptide of collagen III (PIIINP). The effects of sacubitril/valsartan on biomarkers were compared with enalapril. Baseline biomarker values and changes from baseline to 8 months were related to primary outcome.

RESULTS

At baseline, the profibrotic biomarkers aldosterone, sST2, TIMP-1, Gal-3, PINP, and PIIINP were higher, and biomarkers associated with collagen degradation, MMP-2 and -9, were lower than published referent control values. Eight months after randomization, aldosterone, sST2, TIMP-1, MMP-9, PINP, and PIIINP had decreased more in the sacubitril/valsartan than enalapril group. At baseline, higher values of sST-2, TIMP-1, and PIIINP were associated with higher primary outcome rates. Changes from baseline to 8 months in sST-2 and TIMP-1 were associated with change in outcomes.

CONCLUSIONS

Biomarkers associated with profibrotic signaling are altered in HF with reduced ejection fraction, sacubitril/valsartan significantly decreased many of these biomarkers, and these biomarkers have important prognostic value. These findings suggest that sacubitril/valsartan may reduce profibrotic signaling, which may contribute to the improved outcomes. (This Study Will Evaluate the Efficacy and Safety of LCZ696 Compared to Enalapril on Morbidity and Mortality of Patients With Chronic Heart Failure [PARADIGM-HF]; NCT01035255).

Current understanding of fibrosis in genetic cardiomyopathies

Myocardial fibrosis is the excessive deposition of extracellular matrix proteins, including collagens, in the heart. In cardiomyopathies, the formation of interstitial fibrosis and/or replacement fibrosis is almost always part of the pathological cardiac remodeling process. Different forms of cardiomyopathies show particular patterns of myocardial fibrosis that can be considered as distinctive hallmarks. Although formation of fibrosis is initially aimed to be a reparative mechanism, in the long term, on-going and excessive myocardial fibrosis may lead to arrhythmias and stiffening of the heart wall and subsequently to diastolic dysfunction. Ultimately, adverse remodeling with progressive myocardial fibrosis can lead to heart failure. Not surprisingly, the presence of fibrosis in cardiomyopathies, even when subtle, has consistently been associated with complications and adverse outcomes. In the last decade, non-invasive in vivo techniques for visualization of myocardial fibrosis have emerged, and have been increasingly used in research and in the clinic. In this review, we will describe the epidemiology, distribution, and role of myocardial fibrosis in genetic cardiomyopathies, including hypertrophic, dilated, arrhythmogenic, and non-compaction cardiomyopathy, and a few specific forms of genetic cardiomyopathies.

Agreement between gadolinium-enhanced cardiac magnetic resonance and electro-anatomical maps in patients with non-ischaemic dilated cardiomyopathy and ventricular arrhythmias

AIMS

We sought to investigate the overlap between late gadolinium enhancement (LGE) in cardiac magnetic resonance (CMR) and electro-anatomical maps (EAM) of patients with non-ischaemic dilated cardiomyopathy (NIDCM) and how it relates with the outcomes after catheter ablation of ventricular arrhythmias (VA).

METHODS AND RESULTS

We identified 50 patients with NIDCM who received CMR and ablation for VA. Late gadolinium enhancement was detected in 16 (32%) patients, mostly in those presenting with sustained ventricular tachycardia (VT): 15 patients. Low-voltage areas (<1.5 mV) were observed in 23 (46%) cases; in 7 (14%) cases without evidence of LGE. Using a threshold of 1.5 mV, a good and partially good agreement between the bipolar EAM and LGE-CMR was observed in only 4 (8%) and 9 (18%) patients, respectively. With further adjustments of EAM to match the LGE, we defined new cut-off limits of median 1.5 and 5 mV for bipolar and unipolar maps, respectively. Most VT exits (12 out of 16 patients) were found in areas with LGE. VT exits were found in segments without LGE in two patients with VT recurrence as well as in two patients without recurrence, P = 0.77. In patients with VT recurrence, the LGE volume was significantly larger than in those without recurrence: 12% ± 5.8% vs. 6.9% ± 3.4%; P = 0.049.

CONCLUSIONS

In NIDCM, the agreement between LGE and bipolar EAM was fairly poor but can be improved with adjustment of the thresholds for EAM according to the amount of LGE. The outcomes were related to the volume of LGE.

Cardiac involvement in idiopathic inflammatory myopathies detected by cardiac magnetic resonance imaging

Cardiac involvement in idiopathic inflammatory myopathies (IIM) adversely affects prognosis but is commonly sub-clinical. Cardiac magnetic resonance imaging (CMR) is an effective imaging modality for detecting myocardial inflammation and fibrosis but its use as a screening tool for cardiac disease in IIM has not been fully explored. Nineteen patients with IIM without cardiac symptoms underwent CMR using a specific cardiomyopathy protocol including specific sequences detecting focal and diffuse myocardial fibrosis. 9/19 patients demonstrated late gadolinium enhancement (LGE (3/9 right ventricular insertion, 1/9 sub-endocardial, 7/9 mid-wall/sub-epicardial)). T1 mapping was performed in 15 patients. In total, 7/15 had elevated native T1 values, of which four had detected LGE. Myocardial fibrosis was frequently detected in IIM patients without cardiac history. Detection of LGE and elevated T1 values may have negative prognostic implications. Longitudinal studies determining whether early or augmented treatment has a role in patients with sub-clinical cardiac involvement are needed.Key Points• Cardiac involvement in myositis adversely affects prognosis.• Cardiac magnetic resonance imaging is an effective tool for detecting cardiac involvement.• T1 mapping is a technique which detects diffuse myocardial inflammation and fibrosis.• In our study, focal and diffuse myocardial fibrosis was frequently found in myositis patients without cardiac symptoms.

Construction of CNA35 Collagen-Targeted Phase-Changeable Nanoagents for Low-Intensity Focused Ultrasound-Triggered Ultrasound Molecular Imaging of Myocardial Fibrosis in Rabbits

Myocardial fibrosis plays an important role in the development of heart failure and malignant arrhythmia, which potentially increases the incidence of sudden cardiac death. Therefore, early detection of myocardial fibrosis is of great significance for evaluating the prognosis of patients and formulating appropriate treatment strategies. Late gadolinium-enhanced magnetic resonance imaging is considered as the currently effective strategy for noninvasive detection of myocardial fibrosis, but it still suffers from some critical issues. In this work, multifunctional CNA35-labeled perfluoropentane nanoparticles (CNA35-PFP NPs) have been elaborately designed and constructed for molecular imaging of fibrotic myocardium based on ultrasound imaging. These as-constructed CNA35-PFP NPs are intravenously infused into rabbit circulation with an animal model of myocardial infarction. Especially, these targeted CNA35-PFP NPs with nanoscale size could efficiently pass through the endothelial cell gap and adhere to the surface of fibroblasts in the fibrotic myocardium. Importantly, followed by low-intensity focused ultrasound irradiation on the myocardium, these intriguing CNA35-PFP NPs could transform from liquid into gaseous microbubbles, which further significantly enhanced the ultrasound contrast in the fibrotic area, facilitating the detection by diagnostic ultrasound imaging. Therefore, this work provides a desirable noninvasive, economical, and real-time imaging technique for the assessment of cardiac fibrosis with diagnostic ultrasound based on the rational design of liquid-to-gas phase-changeable nanoplatforms.

The Role of Cardiac MRI in the Management of Ventricular Arrhythmias in Ischaemic and Non-ischaemic Dilated Cardiomyopathy

Ventricular tachycardia (VT) and VF account for the majority of sudden cardiac deaths worldwide. Treatments for VT/VF include anti-arrhythmic drugs, ICDs and catheter ablation, but these treatments vary in effectiveness and carry substantial risks and/or expense. Current methods of selecting patients for ICD implantation are imprecise and fail to identify some at-risk patients, while leading to others being overtreated. In this article, the authors discuss the current role and future direction of cardiac MRI (CMRI) in refining diagnosis and personalising ventricular arrhythmia management. The capability of CMRI with gadolinium contrast delayed-enhancement patterns and, more recently, T1 mapping to determine the aetiology of patients presenting with heart failure is well established. Although CMRI imaging in patients with ICDs can be challenging, recent technical developments have started to overcome this. CMRI can contribute to risk stratification, with precise and reproducible assessment of ejection fraction, quantification of scar and 'border zone' volumes, and other indices. Detailed tissue characterisation has begun to enable creation of personalised computer models to predict an individual patient's arrhythmia risk. When patients require VT ablation, a substrate-based approach is frequently employed as haemodynamic instability may limit electrophysiological activation mapping. Beyond accurate localisation of substrate, CMRI could be used to predict the location of re-entrant circuits within the scar to guide ablation.

Ventricular arrhythmia and sudden cardiac death in Fabry disease: a systematic review of risk factors in clinical practice

Fabry disease (FD) is an X-linked lysosomal storage disorder caused by deficiency of α-galactosidase A enzyme. Cardiovascular (CV) disease is a common cause of mortality in FD, in particular as a result of heart failure and arrhythmia, with a significant proportion of events categorized as sudden. There are no clear models for risk prediction in FD. This systematic review aims to identify the risk factors for ventricular arrhythmia (VA) and sudden cardiac deaths (SCD) in FD. A systematic search was performed following PRISMA guidelines of EMBASE, Medline, PubMed, Web of Science, and Cochrane from inception to August 2016, focusing on identification of risk factors for the development of VA or SCD. Thirteen studies were included in the review (n = 4185 patients) from 1189 articles, with follow-up of 1.2-10 years. Weighted average age was 37.6 years, and 50% were male. Death from any cause was reported in 8.3%. Of these, 75% was due to CV problems, with the majority being SCD events (62% of reported deaths). Ventricular tachycardia was reported in 7 studies, with an average prevalence of 15.3%. Risk factors associated with SCD events were age, male gender, left ventricular hypertrophy, late gadolinium enhancement on CV magnetic resonance imaging, and non-sustained ventricular tachycardia. Although a multi-system disease, FD is a predominantly cardiac disease from a mortality perspective, with death mainly from SCD events. Limited evidence highlights the importance of clinical and imaging risk factors that could contribute to improved decision-making in the management of FD.

2019 HRS/EHRA/APHRS/LAHRS expert consensus statement on catheter ablation of ventricular arrhythmias

Ventricular arrhythmias are an important cause of morbidity and mortality and come in a variety of forms, from single premature ventricular complexes to sustained ventricular tachycardia and fibrillation. Rapid developments have taken place over the past decade in our understanding of these arrhythmias and in our ability to diagnose and treat them. The field of catheter ablation has progressed with the development of new methods and tools, and with the publication of large clinical trials. Therefore, global cardiac electrophysiology professional societies undertook to outline recommendations and best practices for these procedures in a document that will update and replace the 2009 EHRA/HRS Expert Consensus on Catheter Ablation of Ventricular Arrhythmias. An expert writing group, after reviewing and discussing the literature, including a systematic review and meta-analysis published in conjunction with this document, and drawing on their own experience, drafted and voted on recommendations and summarized current knowledge and practice in the field. Each recommendation is presented in knowledge byte format and is accompanied by supportive text and references. Further sections provide a practical synopsis of the various techniques and of the specific ventricular arrhythmia sites and substrates encountered in the electrophysiology lab. The purpose of this document is to help electrophysiologists around the world to appropriately select patients for catheter ablation, to perform procedures in a safe and efficacious manner, and to provide follow-up and adjunctive care in order to obtain the best possible outcomes for patients with ventricular arrhythmias.

Comparable survival in ischemic and nonischemic cardiomyopathy secondary to ventricular tachyarrhythmias and aborted cardiac arrest

OBJECTIVES

The study sought to assess the impact of ischemic cardiomyopathy (ICMP) and nonischemic cardiomyopathy (NICMP) on secondary survival in patients presenting with ventricular tachyarrhythmias and aborted sudden cardiac arrest (SCA).

BACKGROUND

Data regarding the outcome of patients with ICMP or NICMP presenting with ventricular tachyarrhythmias or aborted SCA is limited.

PATIENTS AND METHODS

A large retrospective registry was used including all consecutive patients presenting with ventricular tachycardia (VT), ventricular fibrillation (VF), or aborted SCA on admission from 2002 to 2016. ICMP and NICMP were compared applying univariable correlation models and propensity score matching for evaluation of the primary prognostic end point defined as long-term all-cause mortality at 2.5 years. Secondary end points were all-cause mortality at 30 days, at index hospitalization, and after discharge; the composite end point of recurrent ventricular tachyarrhythmias, cardiac death at 24 h, and appropriate implantable cardioverter defibrillator (ICD) therapy; and finally, rehospitalization related to ventricular tachyarrhythmias.

RESULTS

A total of 276 matched patients were included. The rates of VT and VF were similar in both groups (VT: 75 vs. 73%; VF: 23 vs. 22%). At 2.5 years, no differences were found regarding the primary end point of all-cause mortality in both patients with ICMP and NICMP (mortality rate: 33 vs. 32%; log-rank P=0.898). Similar survival was present irrespective of the presence of acute myocardial infarction, underlying ventricular tachyarhythmia (VT/VF), left ventricular dysfunction, and an activated ICD. Furthermore, no significant differences could be seen regarding secondary end points of all-cause mortality at 30 days, at index hospitalization, and after discharge; the composite end point of recurrent ventricular tachyarrhythmias, cardiac death at 24 h, and appropriate ICD interrogation; and finally rehospitalization related to ventricular tachyarrhythmias.

CONCLUSION

Both ICMP and NICMP reveal comparable secondary survival after episodes of ventricular tachyarrhythmias or SCA on admission.

Prognostic implications of late gadolinium enhancement at the right ventricular insertion point in patients with non-ischemic dilated cardiomyopathy: A multicenter retrospective cohort study

Introduction

The presence of late gadolinium enhancement (LGE) at the right ventricular insertion point (RVIP) on cardiac magnetic resonance (CMR) is generally believed to be nonspecific, but the clinical implication of this unique LGE pattern in patients with non-ischemic dilated cardiomyopathy (NICM) has not been elucidated.

Objectives

We investigated the prognostic significance of RVIP-LGE in NICM patients.

Methods

A total of 360 consecutive NICM patients referred for CMR (102 with no LGE, 50 with RVIP-LGE, 121 with left ventricular [LV]-LGE, and 87 with both an LV and RVIP-LGE) were studied. The primary endpoint was a composite of the all-cause death, hospitalization due to worsening of heart failure, and major arrhythmic events.

Results

During a mean follow-up of 45.2 ± 36.5 months, 149 (41.4%) patients (22 [21.6%] no LGE vs. 16 [32.0%] RVIP-LGE vs. 62 [51.2%] LV-LGE vs. 49 [56.3%] both LV and RVIP-LGE, P < 0.0001) reached the primary endpoint. A Kaplan Meier curve demonstrated that RVIP-LGE patients had an intermediate trend of an event free survival rate for the composite endpoint (log-rank P < 0.0001). In a multivariable Cox regression model, LV-LGE (P = 0.008) and both LV and RVIP-LGE (P = 0.003) were significantly associated with a worse outcome, whereas RVIP-LGE was not (P = 0.101). In addition, RVIP-LGE patients (n = 32) had a more favorable outcome compared to LV-LGE patients (n = 32) even after matching the extent of the LGE (median 3.4% [interquartile range, 3.1–3.8], 8 [25.0%] RVIP-LGE vs. 20 [62.5%] LV-LGE, P = 0.002).

Conclusions

LGE confined to the RVIP among NICM patients did not significantly increase the risk of adverse cardiac events, and also showed a better outcome than the same extent of LGE located in the LV. Identification of this unique LGE distribution may help refine the current risk stratification.

Ultrasound evaluation of left ventricular and aortic fibrosis after pre-eclampsia

OBJECTIVES

Myocardial fibrosis is associated with adverse clinical outcome in adults. Our aim was to investigate using echocardiographic calibrated integrated backscatter (cIBS) the presence of myocardial and/or aortic fibrosis in asymptomatic women with a history of early-onset (EO) or late-onset (LO) pre-eclampsia (PE).

METHODS

Thirty non-pregnant women whose most recent pregnancy was complicated by EO-PE, 30 with previous LO-PE pregnancy and 30 controls who had experienced only uncomplicated pregnancy previously were selected retrospectively from our electronic database and recalled between 6 months and 4 years after delivery. Data regarding gestational age (GA) and mean uterine artery (UtA) pulsatility index (PI) at diagnosis of PE were collected from their medical records. The women underwent cardiovascular assessment, during which the presence of fibrosis was investigated, by means of cIBS, at the basal interventricular septum (cIBS_IVS ), the basal posterior wall (cIBS_PW ) and the anterior wall of the ascending aorta, 3 cm above the valve (cIBS_AO ). These findings were compared between the three patient groups.

RESULTS

Using cIBS imaging, we found significant left ventricular (LV) fibrosis in women with a history of EO-PE compared with those with previous LO-PE pregnancy and controls (intergroup ANOVA P < 0.001 for cIBS_IVS and P = 0.005 for cIBS_PW ), whereas aortic fibrosis did not differ significantly among cases and controls. Stepwise multivariate regression analysis showed that LV fibrosis was associated independently with lower GA and higher mean UtA-PI at diagnosis of PE, while cIBS_AO correlated with aortic diameters, stiffness and ventricular-arterial coupling.

CONCLUSIONS

Women with a history of EO-PE show LV fibrosis in the short-medium term after delivery compared with women with previous LO-PE pregnancy and controls. LV fibrosis is associated with GA and mean UtA-PI at onset of PE. Larger studies using cardiac magnetic resonance imaging are needed to validate and confirm our findings. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Ventricular arrhythmias in patients with Takotsubo syndrome

Takotsubo syndrome (TTS) is a unique nonischemic cardiac disease characterized by acute myocardial dysfunction of the left and/or right ventricle. Patients are predominantly postmenopausal women and usually present with symptoms indistinguishable from acute coronary syndrome. Although the exact pathomechanisms of TTS remain elusive, increasing evidence suggests that sympathetic overdrive and catecholamine excess might play a central role. Despite the complete recovery of ventricular dysfunction within several days to weeks, patients with TTS exhibit considerable short- and long-term mortality rates and ventricular arrhythmias have been identified as key contributor to morbidity and mortality. This article summarizes the prevalence, underlying mechanisms, therapeutic strategies, and prognostic implications of ventricular arrhythmias in TTS. Furthermore, the need for implantable cardioverter-defibrillators is discussed in view of the transient character of the disease.

Sudden Cardiac Death Risk Prediction: The Role of Cardiac Magnetic Resonance Imaging

Sudden cardiac death (SCD) accounts for more than 4 million global deaths per year. While it is most commonly caused by coronary artery disease, a final common pathway of ventricular arrhythmias is shared by different etiologies. The most effective primary and secondary prevention strategy is an implantable cardioverter-defibrillator (ICD). The decision to implant an ICD for primary prevention is largely based on a left ventricular ejection fraction ≤ 35%, but this criterion in isolation is neither sensitive nor specific. Novel imaging parameters hold promise to improve ICD candidate selection. Cardiac magnetic resonance (CMR) imaging is a powerful and versatile technique, with the ability to comprehensively assess cardiac structure and function. A range of variables based on CMR techniques (late gadolinium enhancement, T₁ mapping, T₂* relaxometry, deformation imaging) have been associated with ventricular arrhythmias and SCD risk. The role of CMR in the estimation of ventricular arrhythmias and SCD risk in coronary artery disease, nonischemic cardiomyopathies, cardiac transplant, iron-overload cardiomyopathy and valvular heart disease is reviewed in this article. Prospective, randomized trials and standardization of CMR techniques are required before its routine use can be recommended for guiding SCD prevention strategies.

The Prognostic Value of Late Gadolinium-Enhanced Cardiac Magnetic Resonance Imaging in Nonischemic Dilated Cardiomyopathy: A Review and Meta-Analysis

OBJECTIVES

This review and meta-analysis reviews the prognostic value of cardiac magnetic resonance (CMR) in nonischemic dilated cardiomyopathy (DCM).

BACKGROUND

Late gadolinium-enhanced (LGE) CMR is a noninvasive method to determine the underlying cause of DCM and previous studies reported the prognostic value of the presence of LGE to identify patients at risk of major adverse cardiovascular events.

METHODS

PubMed was searched for studies describing the prognostic implication of LGE in patients with DCM for the specified endpoints cardiovascular mortality, major ventricular arrhythmic events including appropriate implantable cardioverter-defibrillator therapy, rehospitalization for heart failure, and left ventricular reverse remodeling.

RESULTS

Data from 34 studies were included, with a total of 4,554 patients. Contrast enhancement was present in 44.8% of DCM patients. Patients with LGE had increased cardiovascular mortality (odds ratio [OR]: 3.40; 95% confidence interval [CI]: 2.04 to 5.67), ventricular arrhythmic events (OR: 4.52; 95% CI: 3.41 to 5.99), and rehospitalization for heart failure (OR: 2.66; 95% CI: 1.67 to 4.24) compared with those without LGE. Moreover, the absence of LGE predicted left ventricular reverse remodeling (OR: 0.15; 95% CI: 0.06 to 0.36).

CONCLUSIONS

The presence of LGE on CMR substantially worsens prognosis for adverse cardiovascular events in DCM patients, and the absence indicates left ventricular reverse remodeling.

Long-term prognostic value of combined free triiodothyronine and late gadolinium enhancement in nonischemic dilated cardiomyopathy

BACKGROUND

Thyroid dysfunction and myocardial fibrosis are both associated with cardiovascular events in patients with dilated cardiomyopathy (DCM).

HYPOTHESIS

The combination of thyroid hormone (TH) and myocardial fibrosis (detected by late gadolinium enhancement [LGE]) is an independent and incremental predictor of adverse events in DCM.

METHODS

We consecutively enrolled 220 idiopathic DCM patients with thyroid function and LGE assessment at Fuwai Hospital (China) from January 2010 to October 2011 and followed up through December 2015. Patients were divided into 4 groups according to the presence or absence of LGE and FT3 value (median level of 2.79 pg/mL): LGE-positive + FT3 < 2.79 pg/mL, LGE-positive + FT3 ≥ 2.79 pg/mL, LGE-negative + FT3 < 2.79 pg/mL, and LGE-negative + FT3 ≥ 2.79 pg/mL.

RESULTS

During a median follow-up of 61 months, 56 patients (25.5%) died, with 27/56 (48.2%), 8/45 (17.8%), 12/54 (22.2%), and 9/65 (13.8%) among 4 groups (P = 0.009), respectively. Multivariable Cox regression analysis identified LGE-positive and FT3 < 2.79 pg/mL as a significant independent predictor of all-cause mortality (hazard ratio: 2.893, 95% confidence interval: 1.323-6.326, P = 0.008). Combining the predictive value of FT3 and LGE status significantly improved risk reclassification for all-cause mortality, as indicated by the net reclassification improvement (0.28; P = 0.005) and integrated discrimination improvement (0.058; P = 0.001).

CONCLUSIONS

The findings suggest that the combination of FT3 and LGE yielded a more accurate predictive value for long-term prognosis in patients with DCM, which may improve patient selection for intensive interventions.

Cardiac Involvement in Duchenne Muscular Dystrophy and Related Dystrophinopathies

Dystrophinopathies include Duchenne muscular dystrophy (DMD), Becker muscular dystrophy (BMD), X-linked dilated cardiomyopathy (XLCM), and facioscapulohumeral muscular dystrophy (FSHD). DMD/BMD are X-linked recessive disorders, related to the synthesis of dystrophin. Most of DMD after the third decade of their age develop cardiomyopathy that remains silent, due to relative physical inactivity. Cardiac disease in female carriers presents with hypertrophy, arrhythmias or dilated cardiomyopathy, clinically overt by increasing age.In ECG, DMD presents increased R/S ratio in the right precordial leads, deep Q waves in the lateral leads, conduction abnormalities, and arrhythmias. Echocardiography, although widely available and inexpensive, is highly depended on the acoustic window and operator's experience. Tissue Doppler can be used to identify early changes of cardiomyopathy and detect progressive cardiac damage. CMR, a noninvasive, nonradiating technique, by evaluation of cardiac volumes, mass, ejection fraction, inflammation, and fibrosis, is ideal for early diagnosis. Subepicardial fibrosis in the inferolateral wall is the typical CMR lesion in DMD/BMD.Early initiation of angiotensin converting enzyme inhibitors (ACEI) treatment, such as perindopril, was associated with lower mortality in DMD with normal LV ejection fraction at study entry. Other studies documented that a beta-blocker (BB), in addition to ACEI, improves LV systolic function in MD. These encouraging results recommend initiation of ACEI and/or BB early after diagnosis of the muscular dystrophy, especially in DMD.

Oedema-fibrosis in Duchenne Muscular Dystrophy: Role of cardiovascular magnetic resonance imaging

Duchenne muscular dystrophy (DMD) is an X-linked muscle disorder characterized by progressive, irreversible loss of cardiac and skeletal muscular function. Muscular enlargement in DMD is attributed to oedema, due to the increased cytoplasmic Na+ concentration. The aim of this review was to present the current experience and emphasize the role of cardiovascular magnetic resonance (CMR) in the diagnosis of this condition. DMD patients' survival depends on ventilatory assistance, as respiratory muscle dysfunction was the most common cause of death in the past. Currently, due to improved ventilatory assistance, cardiomyopathy has become the main cause of death, even though clinically overt heart failure may be absent. CMR is the technique of choice to assess the pathophysiologic phenomena taking place in DMD, such as myocardial oedema and subepicardial fibrosis. The classic index to assess oedema is the T2-weighted short-tau inversion recovery (T2w-STIR), as it suppresses the signal from flowing blood and resident fat and enhances sensitivity to tissue fluid. Furthermore, CMR is the most reliable technique to detect and quantify fibrosis in DMD. Recently, the new indices T2, T1 mapping (native and postcontrast) and the extracellular volume (ECV) allow a more accurate approach of myocardial oedema and fibrosis. To conclude, the assessment of cardiac oedema and subepicardial fibrosis in the inferolateral wall of the left heart ventricle are the most important early finding in DMD with preserved ventricular function, and CMR, using both the classic and the new indices, is the best technique to detect and monitor these lesions.

Cardiovascular consequences of myocardial bridging: A meta-analysis and meta-regression

Myocardial bridging, a congenital abnormality in which a coronary artery tunnels through the myocardial fibres was usually considered a benign condition. Many studies suggested a potential hemodynamic significance of myocardial bridging and some, usually case reports, implied a possible correlation between it and various cardiovascular pathologies like acute myocardial infarction, ventricular rupture, life-threatening arrhythmias, hypertrophic cardiomyopathy, apical ballooning syndrome or sudden death. The main objective of this article is to evaluate whether myocardial bridging may be associated with significant cardiac effects or if it is strictly a benign anatomical variation. To this purpose, we performed a meta-analysis (performed using the inverse variance heterogeneity model) and meta-regression, on scientific articles selected from three main databases (Scopus, Web of Science, Pubmed). The study included 21 articles. MB was associated with major adverse cardiac events - OR = 1.52 (1.01–2.30), and myocardial ischemia OR = 3.00 (1.02–8.82) but not with acute myocardial infarction, cardiovascular death, ischemia identified using imaging techniques, or positive exercise stress testing. Overall, myocardial bridging may have significant cardiovascular consequences (MACE, myocardial ischemia). More studies are needed to reveal/refute a clear association with MI, sudden death or other cardiovascular pathologies.

Cardiac magnetic resonance imaging: Which information is useful for the arrhythmologist?

Cardiac magnetic resonance (CMR) is a non-invasive, non-ionizing, diagnostic technique that uses magnetic fields, radio waves and field gradients to generate images with high spatial and temporal resolution. After administration of contrast media (e.g., gadolinium chelate), it is also possible to acquire late images, which make possible the identification and quantification of myocardial areas with scar/fibrosis (late gadolinium enhancement, LGE). CMR is currently a useful instrument in clinical cardiovascular practice for the assessment of several pathological conditions, including ischemic and non-ischemic cardiomyopathies and congenital heart disease. In recent years, its field of application has also extended to arrhythmology, both in diagnostic and prognostic evaluation of arrhythmic risk and in therapeutic decision-making. In this review, we discuss the possible useful applications of CMR for the arrhythmologist. It is possible to identify three main fields of application of CMR in this context: (1) arrhythmic and sudden cardiac death risk stratification in different heart diseases; (2) decision-making in cardiac resynchronization therapy device implantation, presence and extent of myocardial fibrosis for left ventricular lead placement and cardiac venous anatomy; and (3) substrate identification for guiding ablation of complex arrhythmias (atrial fibrillation and ventricular tachycardias).

Dilated Cardiomyopathy: Genetic Determinants and Mechanisms

Nonischemic dilated cardiomyopathy (DCM) often has a genetic pathogenesis. Because of the large number of genes and alleles attributed to DCM, comprehensive genetic testing encompasses ever-increasing gene panels. Genetic diagnosis can help predict prognosis, especially with regard to arrhythmia risk for certain subtypes. Moreover, cascade genetic testing in family members can identify those who are at risk or with early stage disease, offering the opportunity for early intervention. This review will address diagnosis and management of DCM, including the role of genetic evaluation. We will also overview distinct genetic pathways linked to DCM and their pathogenetic mechanisms. Historically, cardiac morphology has been used to classify cardiomyopathy subtypes. Determining genetic variants is emerging as an additional adjunct to help further refine subtypes of DCM, especially where arrhythmia risk is increased, and ultimately contribute to clinical management.

Novel approaches to the prediction, diagnosis and treatment of cardiac late effects in survivors of childhood cancer: a multi-centre observational study

BACKGROUND

Anthracycline-induced cardiac toxicity is a cause of significant morbidity and early mortality in survivors of childhood cancer. Current strategies for predicting which children are at greatest risk for toxicity are imperfect and diagnosis of cardiac injury is usually made relatively late in the natural history of the disease. This study aims to identify genomic, biomarker and imaging parameters that can be used as predictors of risk or aid in the early diagnosis of cardiotoxicity.

METHODS

This is a prospective longitudinal cohort study that recruited two cohorts of pediatric cancer patients at six participating centres: (1) an Acute Cohort of children newly diagnosed with cancer prior to starting anthracycline therapy (n = 307); and (2) a Survivor Cohort of long-term survivors of childhood cancer with past exposure to anthracycline (n = 818). The study team consists of three collaborative cores. The Genomics Core is identifying genomic variations in anthracycline metabolism and in myocardial response to injury that predispose children to treatment-related cardiac toxicity. The Biomarker Core is identifying existing and novel biomarkers that allow for early diagnosis and prognosis of anthracycline-induced cardiac toxicity. The Imaging Core is identifying echocardiographic and cardiac magnetic resonance (CMR) imaging parameters that correspond to early signs of cardiac dysfunction and remodeling and precede global dysfunction and clinical symptoms. The data generated by the cores will be combined to create an integrated risk-prediction model aimed at more accurate identification of children who are most susceptible to anthracycline toxicity.

DISCUSSION

We aim to identify genomic risk factors that predict risk for anthracycline cardiotoxicity pre-exposure and imaging and biomarkers that facilitate early diagnosis of cardiac injury. This will facilitate a personalized approach to identifying at-risk children with cancer who may benefit from cardio- protective strategies during therapy, and closer surveillance and earlier initiation of medications to preserve heart function after cancer therapy.

TRIAL REGISTRATION

NCT01805778 . Registered 28 February 2013; retrospectively registered.

Sudden cardiac death in nonischemic cardiomyopathy: Refining risk assessment

Sudden cardiac death (SCD) risk assessment among patients with nonischemic cardiomyopathy (NICM) has been has been less straightforward than for patients with ischemic cardiomyopathy. The common surrogate that has been associated with highest SCD risk for all cardiomyopathies, and which has been universally used to guide implantation of primary-prevention implantable cardioverter-defibrillators (ICDs), is left ventricular ejection fraction (LVEF) ≤35%. However, this practice has been called into question, especially in light of recent trials suggesting that ICD treatment may not be of additional survival benefit among those with NICM treated with optimal medical therapy. This Clinical Review attempts to offer refinements to the current practice of SCD risk assessment among patients with NICM, with specific focus on importance of NICM etiology and efforts to identify myocardial scarring and arrhythmogenic substrate, both of which may provide greater information about SCD risk than the LVEF alone. These concepts are illustrated further as they apply to hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, and cardiac sarcoidosis, all of which are increasingly recognized NICM substrates associated with SCD and for which refinements for assessing risk are lacking in conventional guidelines.

Usefulness of Left Atrial Emptying Fraction to Predict Ventricular Arrhythmias in Patients With Implantable Cardioverter Defibrillators

Impaired left atrial emptying fraction (LAEF) is an important predictor of mortality in patients with heart failure. As it may reflect increased LV wall stress, it might predict ventricular arrhythmia (VA) specifically. This study evaluated the predictive value of LAEF assessed with cardiovascular magnetic resonance (CMR) imaging with respect to appropriate device therapy (ADT) for VA and compared its role with CMR assessed scar size and other risk factors. In total, 229 patients (68% male, 63 ± 10 years, 61% ischemic cardiomyopathy) with LV ejection fraction ≤35% who underwent CMR and implantable cardioverter defibrillator (ICD) implantation for primary prevention in 2005 to 2012 were included. CMR was used to quantify LV volumes and function. LV scar size was quantified when late gadolinium enhancement was available (n = 166). Maximum and minimum left atrial volumes and LAEF were calculated using the biplane area-length method. The occurrence of ADT and mortality was assessed during a median follow-up of 3.9 years. Sixty-two patients (27%) received ADT. Univariable Cox analysis showed that male gender, creatinine level, minimum left atrial volume, LAEF, and total scar size were significant predictors of ADT. In multivariable Cox analysis, LAEF (hazard ratio 0.75 per 10%, p <0.01), and scar size (hazard ratio 1.03 per g, p = 0.03) remained the only independent predictors of ADT. Patients with both LAEF > median and scar size < median were at low risk (13% ADT at 5 years), whereas those with LAEF < median and scar size > median experienced 40% ADT at 5 years (log-rank p = 0.01). In conclusion, LAEF independently predicts ADT in patients with primary prevention ICDs. Combined assessment of LAEF and scar size identifies a group with low risk of ADT. Therefore, LAEF assessment could assist in risk stratification for VA to select patients with the highest benefit from ICD implantation.

Personalizing Risk Stratification for Sudden Death in Dilated Cardiomyopathy: The Past, Present, and Future

Results from the DANISH Study (Danish Study to Assess the Efficacy of ICDs in Patients With Non-Ischemic Systolic Heat Failure on Mortality) suggest that for many patients with dilated cardiomyopathy (DCM), implantable cardioverter-defibrillators do not increase longevity. Accurate identification of patients who are more likely to die of an arrhythmia and less likely to die of other causes is required to ensure improvement in outcomes and wise use of resources. Until now, left ventricular ejection fraction has been used as a key criterion for selecting patients with DCM for an implantable cardioverter-defibrillator for primary prevention purposes. However, registry data suggest that many patients with DCM and an out-of-hospital cardiac arrest do not have a markedly reduced left ventricular ejection fraction. In addition, many patients with reduced left ventricular ejection fraction die of nonsudden causes of death. Methods to predict a higher or lower risk of sudden death include the detection of myocardial fibrosis (a substrate for ventricular arrhythmia), microvolt T-wave alternans (a marker of electrophysiological vulnerability), and genetic testing. Midwall fibrosis is identified by late gadolinium enhancement cardiovascular magnetic resonance imaging in ≈30% of patients and provides incremental value in addition to left ventricular ejection fraction for the prediction of sudden cardiac death events. Microvolt T-wave alternans represents another promising predictor, supported by large meta-analyses that have highlighted the negative predictive value of this test. However, neither of these strategies have been routinely adopted for risk stratification in clinical practice. More convincing data from randomized trials are required to inform the management of patients with these features. Understanding of the genetics of DCM and how specific mutations affect arrhythmic risk is also rapidly increasing. The finding of a mutation in lamin A/C, the cause of ≈6% of idiopathic DCM, commonly underpins more aggressive management because of the malignant nature of the associated phenotype. With the expansion of genetic sequencing, the identification of further high-risk mutations appears likely, leading to better-informed clinical decision making and providing insight into disease mechanisms. Over the next 5 to 10 years, we expect these techniques to be integrated into the existing algorithm to form a more sensitive, specific, and cost-effective approach to the selection of patients with DCM for implantable cardioverter-defibrillator implantation.