Different Phases of Disease in Lymphocytic Myocarditis: Clinical and Electrophysiological Characteristics

Long-Term Risk Assessment in Athletes With Complex Ventricular Arrhythmias

BACKGROUND

Ventricular arrhythmias (VAs) are a major concern in athletes. We sought to determine the prognostic role of noninvasive and invasive assessments in athletes with complex VAs.

METHODS

One-hundred-ninety athletes (82% male; 28 [19-43] years; 148 [78%] competitive athletes) with frequent or exercise-induced premature ventricular complexes or nonsustained ventricular tachycardia were included in a multicenter cohort study and categorized based on VA ECG morphology into common (n=99) and uncommon (n=91) VA groups. Each athlete underwent a comprehensive diagnostic workup, including cardiac magnetic resonance in 94% (n=178) and electrophysiology study/electroanatomical mapping in 87% (n=166). The primary end point was the occurrence of sudden death or sustained VAs during long-term follow-up.

RESULTS

Athletes with uncommon VA morphology had higher rates of abnormal findings at multimodality assessment and more final diagnoses of structural heart disease. Over a median follow-up of 6.2 (4.3-8.1) years, 7 (4%) athletes experienced a primary outcome event, including 1 sudden death. Interestingly, no events occurred in athletes with common morphology VAs. In univariable Cox models, factors associated with the primary end point included uncommon VA morphology (P=0.003), lack of VA suppression (P=0.049), and nonsustained ventricular tachycardia/ventricular tachycardia induction (P=0.010) during stress testing, late gadolinium enhancement (P=0.045), electroanatomical scar regions (P=0.022), and sustained VA inducibility by electrophysiology study (P<0.001). Incorporating findings of invasive tests improved prediction of primary outcome events over clinical/noninvasive findings in isolation (log-likelihood ratio for nested models, P=0.004). A survival tree model based on VA morphology, late gadolinium enhancement, VA response to exercise testing, and electroanatomical mapping allowed risk stratification, identifying subgroups of athletes without primary outcome events during follow-up. Among 148 competitive athletes, 101 (68%) regained eligibility after 3 months of detraining, but only 42 (28%) continued long-term.

CONCLUSIONS

A comprehensive diagnostic assessment integrating ECG, stress testing, and imaging findings, along with the selective use of invasive electrophysiology assessments, may help refine the prognostic evaluation of athletes with complex VAs.

Immune Profile and MRI-Detected Cardiac Fibrosis and Edema in Hypertensive and Non-Hypertensive Patients with COVID-19

Cardiac involvement in 2019 coronavirus disease (COVID-19) survivors has been reported frequently. An exacerbated immune response may be the main mechanism of myocardial injury and late cardiac sequelae in this population. Background/Objectives: We investigated the immune profile in hypertensive and non-hypertensive patients with COVID-19 who developed late cardiac fibrosis and edema, as detected by magnetic resonance imaging (MRI). Methods: We evaluated associations of cytokine and immune-cell subset levels during hospitalization for COVID-19 with the presence of myocardial interstitial fibrosis [represented by the extracellular volume (ECV)] or edema (represented by the T2), detected by cardiac MRI examination after discharge, in hypertensive and non-hypertensive patients. Results: Patients with hypertension had reduced B-cell percentages, increased natural killer cell percentages, and higher interleukin (IL)-4, IL-5, IL-13, IL-17A, and tumor necrosis factor-β levels compared to patients without hypertension. Larger percentages of human leukocyte antigen DR isotope+ blood cells, reflecting CD8+ T-cell activation, correlated with increased T2 and ECV in hypertensive patients. The HLA-DR mean fluorescence intensity was associated with ECV in non-hypertensive patients. Conclusions: Our findings reveal cytokine and immune-cell dysregulation in both hypertensive and non-hypertensive patients with COVID-19, along with moderate correlations between CD8+ T-cell activation and increased cardiac MRI markers of myocardial interstitial fibrosis and edema. These results contribute to a deeper understanding of immune dysfunction mechanisms involved in myocardial remodeling.

Prognostic value of electroanatomic-guided endomyocardial biopsy in patients with myocarditis, arrhythmogenic cardiomyopathy and non dilated left ventricular cardiomyopathy

A wide variety of non-invasive and invasive techniques for SCD risk stratification in non ischemic cardiomyopathy (NICM) have been proposed, including left ventricular (LV) ejection fraction, QRS duration, late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) and invasive electrophysiologic study with or without three-dimensional electroanatomic mapping (3D-EAM), to identify and characterize the arrhythmogenic substrate. There is still no clear consensus on the risk stratification in this clinical setting. The aim of our study is to characterize the 3D-EAM substrate in patients with the same clinical presentation of unexplained complex VAs and NICM using CMR, three-dimensional electranatomic mapping (3D-EAM) in association with endomyocardial biopsy (EMB) and genetic screening, as a more precise and early diagnostic assessment may provide important subsequent prognostic impact. The study was designed as a prospective multi-center observational evaluation and the patient follow-up was scheduled at 6 months interval. We enrolled 125 patients distinct into four different group by complete diagnostic work-up: myocarditis, non-dilated left ventricular cardiomyopathy, arrhythmogenic cardiomyopathy and control group. The four groups were compared in terms of clinical, imaging and 3D-EAM data. At multivariate analysis sustained VT/VF on admission [HR: 3.64 (1.79-7.4), p < 0.001], total bipolar scar area of left and right ventricle detected by 3D-EAM [HR: 2.24 (1.13-4.49), p = 0.02], histological diagnosis of myocarditis by 3D-EAM guided endomyocardial biopsy (EBM) [HR: 2.79 (1.04-7.44), p = 0.01] were independent predictors of complex VAs or death at follow-up. 3D-EAM guided EMB represent not only a valid diagnostic tool to identify the arrhythmogenic substrate in patients with NICM and ventricular arrhythmic phenotype but also an important predictor of complex Vas at long term follow-up.

Management Status of Myocarditis-Related Sudden Cardiac Death

Myocarditis, a life-threatening disease that can result in cardiac arrest and sudden cardiac death, has garnered significant attention in recent years. This review provides a comprehensive overview of the management of myocarditis-related sudden cardiac death, encompassing its pathology, diagnostic methods, therapeutic strategies, preventive measures, prognostic factors, and risk stratification. Additionally, the review highlights current challenges and future directions in this field. The aim is to enhance understanding of myocarditis-related sudden cardiac death and inform clinical practice, ultimately leading to improved patient outcomes.

Substrate Characterization and Outcomes of Ventricular Tachycardia Ablation in Amyloid Cardiomyopathy: A Multicenter Study

BACKGROUND

Sustained ventricular tachycardia (VT) in cardiac amyloidosis is uncommon, and the substrate and outcomes of catheter ablation are not defined.

METHODS

We included 22 consecutive patients (mean age, 68±10 years; male sex, 91%) with cardiac amyloidosis (ATTR [transthyretin], n=16; light chain, n=6) undergoing catheter ablation for VT/ventricular fibrillation (VF) between 2013 and 2023 in a retrospective, observational, international study. The primary efficacy outcome was recurrent VT/VF during follow-up, while the primary safety end point included major procedure-related adverse events.

RESULTS

The indication for ablation was drug-refractory VT in 17 patients (77%), and premature ventricular complex-initiated polymorphic VT/VF in 5 patients (23%). Catheter ablation was performed using endocardial (n=17.77%) or endo-epicardial approaches (n=5.23%). Complete endocardial electroanatomical voltage maps of the left and right ventricles were obtained in 17 (77%) and 10 (45%) patients, respectively. Each patient had evidence of low-voltage areas, most commonly involving the interventricular septum (n=16); late potentials were recorded in 16 patients (73%). A median of 1 (1-2) VT was inducible per patient; 12 of the 26 mappable VTs (46%) originated from the interventricular septum. Complete procedural success was achieved in 16 patients (73%), with 4 (18%) major procedure-related adverse events. After a median follow-up of 32 (14-42) months, sustained VT/VF recurrence was observed in 9 patients (41%); survival free from VT/VF recurrence was 56% (95% CI, 36%-86%) at 36-month follow-up, and most patients remained on antiarrhythmic drugs. A significant reduction in per patient implantable cardioverter defibrillator therapies was noted in the 6-month period after ablation (before: 6 [4-9] versus after: 0 [0-0]; P<0.001). In multivariable analysis, complete procedural success was associated with reduced risk of recurrent VT/VF (hazard ratio, 0.002; P=0.034).

CONCLUSIONS

Catheter ablation can achieve control of recurrent VT/VF in more than half of patients with cardiac amyloidosis, and the reduction in VT/VF burden post-ablation may be relevant for quality of life. Septal substrate and risk of procedure-related complications challenge successful management of patients with cardiac amyloidosis and VT/VF.

Role of genetics in inflammatory cardiomyopathy

Traditional cardiomyopathy paradigms segregate inflammatory etiologies from those caused by genetic variants. An identified or presumed trigger is implicated in acute myocarditis or chronic inflammatory cardiomyopathy but growing evidence suggests a significant proportion of patients have an underlying cardiomyopathy-associated genetic variant often even when a clear inflammatory trigger is identified. Recognizing a possible genetic contribution to inflammatory cardiomyopathy may have major downstream implications for both the patient and family. The presenting features of myocarditis (i.e. chest pain, arrhythmia, and/or heart failure) may provide insight into diagnostic considerations. One example is isolated cardiac sarcoidosis, a distinct inflammatory cardiomyopathy that carries diagnostic challenges and clinical overlap; genetic testing has increasingly reclassified cases of isolated cardiac sarcoidosis as genetic cardiomyopathy, notably altering management. On the other side, inflammatory presentations of genetic cardiomyopathies are likewise underappreciated and a growing area of investigation. Inflammation plays an important role in the pathogenesis of several familial cardiomyopathies, especially arrhythmogenic phenotypes. Given these clinical scenarios, and the implications on clinical decision making such as initiation of immunosuppression, sudden cardiac death prevention, and family screening, it is important to recognize when genetics may be playing a role.

Characteristics and Clinical Value of Electroanatomic Voltage Mapping in Cardiac Amyloidosis

BACKGROUND

Cardiac amyloidoses (CAs) are an increasingly recognised group of infiltrative cardiomyopathies associated with high risk of adverse cardiac events. We sought to characterise the characteristics and clinical value of right ventricular (RV) electroanatomic voltage mapping (EVM) in CA.

METHODS

Fifteen consecutive patients undergoing endomyocardial biopsy (EMB) for suspected CA (median age 75 years, 1st-3rd quartiles 64-78 years], 67% male) were enrolled in an observational prospective study. Each patient underwent RV high-density EVM using a multipolar catheter and EMB. The primary outcome was death or heart failure hospitalisation at 1-year follow-up. We recorded electrographic features at EMB sampling sites and electroanatomic data in the overall RV, and explored their correlations with histopathologic findings and primary outcomes events.

RESULTS

A final EMB-proven diagnosis of immunoglobulin light chain or transthyretin CA was formulated in 6 and 9 patients, respectively. Electrogram amplitudes in the bipolar and unipolar configurations averaged 1.55 ± 0.44 mV and 5.14 ± 1.50 mV, respectively, in the overall RV, with lower values in AL CA patients. We found a significant inverse correlation between both bipolar and unipolar electrogram amplitude and amyloid burden according to EMB (P = 0.001 and P = 0.025, respectively). At 1-year follow-up, 7 patients (47%) experienced a primary outcome event; the extent of bipolar dense scar area at RV EVM was an independent predictor of primary outcome events at multivariable analysis (odds ratio 2.40; P = 0.037).

CONCLUSIONS

In CA, electrogram amplitudes are around the lower limit of normal yet disproportionately low compared with the increased wall thickness. Out data suggest that RV electrogram amplitude may be a quantitative marker of amyloid burden, and that RV EVM may have prognostic value.

Arrhythmic Mitral Valve Prolapse and Sports Activity: Pathophysiology, Risk Stratification, and Sports Eligibility Assessment

Although mitral valve prolapse (MVP) is the most prevalent valvular abnormality in Western countries and generally carries a good prognosis, a small subset of patients is exposed to a significant risk of malignant ventricular arrhythmias (VAs) and sudden cardiac death (SCD), the so-called arrhythmic MVP (AMVP) syndrome. Recent work has emphasized phenotypical risk features of severe AMVP and clarified its pathophysiology. However, the appropriate assessment and risk stratification of patients with suspected AMVP remains a clinical conundrum, with the possibility of both overestimating and underestimating the risk of malignant VAs, with the inappropriate use of advanced imaging and invasive electrophysiology study on one hand, and the catastrophic occurrence of SCD on the other. Furthermore, the sports eligibility assessment of athletes with AMVP remains ill defined, especially in the grey zone of intermediate arrhythmic risk. The definition, epidemiology, pathophysiology, risk stratification, and treatment of AMVP are covered in the present review. Considering recent guidelines and expert consensus statements, we propose a comprehensive pathway to facilitate appropriate counseling concerning the practice of competitive/leisure-time sports, envisioning shared decision making and the multidisciplinary "sports heart team" evaluation of borderline cases. Our final aim is to encourage an active lifestyle without compromising patients' safety.