Left Ventricular Involvement in ARVD/C

Continuous-flow left ventricular assist device treatment for arrhythmogenic right ventricular cardiomyopathy complicated by advanced biventricular failure - University of Tokyo experiences

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited cardiomyocyte disease characterized by intractable ventricular arrhythmia in the majority of affected patients. Some of these patients also manifest right ventricular dysfunction and heart failure symptoms. Fatal ventricular arrhythmia has been the primary cause of death in ARVC patients. However, increased early recognition of ARVC and improvement in arrhythmic risk stratification and treatment have dramatically improved survival. A small proportion of the patients are further complicated by left ventricular impairment at the late phase in addition to right heart failure, for whom only heart transplantation is the last resort. Because of the relative rarity of ARVC with biventricular failure, no consensus or guideline has been reported on how to effectively support these patients with a mechanical circulatory device. Herein, four ARVC patients with biventricular failure were presented who were successfully bridged to heart transplantation after long-term support by isolated continuous-flow LVAD.

Heart transplantation outcomes in arrhythmogenic right ventricular cardiomyopathy: a contemporary national analysis

Aims

Heart failure is an increasingly recognized later stage manifestation of arrhythmogenic right ventricular cardiomyopathy (ARVC) that can require heart transplantation (HT) to appropriately treat. We aimed to study contemporary ARVC HT outcomes in a national registry.

Methods and results

The United Network for Organ Sharing registry was queried for HT recipients from 1/1994 through 2/2020. ARVC patients were compared with non‐ARVC dilated, restrictive, and hypertrophic cardiomyopathy HT patients (HT for ischaemic and valvular disease was excluded from analysis). Post‐HT survival was assessed using Kaplan–Meier estimates. A total of 189 of 252 (75%) waitlisted ARVC patients (median age 48 years, 65% male) underwent HT, representing 0.3% of the total 65 559 HT during the study time period. Annual frequency of HT for ARVC increased significantly over time. ARVC patients had less diabetes (5% vs. 17%, P < 0.001), less cigarette use (15% vs. 23%, P < 0.001), lower pulmonary artery and pulmonary capillary wedge pressures, and lower cardiac output than the 33 659 non‐ARVC patients (P < 0.001). Ventricular assist device use was significantly lower in ARVC patients (8% vs. 32%, P < 0.001); 1 and 5 year post‐HT survival was 97% and 93% for ARVC vs. 95% and 82% for non‐ARVC HT recipients (P < 0.001). On adjusted multivariable Cox regression, ARVC had decreased risk of post‐HT death compared with non‐ARVC aetiologies (hazard ratio 0.48, 95% confidence interval 0.28–0.82, P = 0.008). Patients with ARVC also had lower risk of death or graft failure than non‐ARVC patients (hazard ratio 0.51, 95% confidence interval 0.32–0.81, P = 0.004).

Conclusions

In the largest series of HT in ARVC, we found that HT is increasingly performed in ARVC, with higher survival compared with other cardiomyopathy aetiologies. The right ventricular predominant pathophysiology may require unique considerations for heart failure management, including HT.

Cardiomyopathies and Genetic Testing in Heart Failure: Role in Defining Phenotype-Targeted Approaches and Management

Cardiomyopathies represent an important cause of heart failure, often affecting young individuals, and have important implications for relatives. Genetic testing for cardiomyopathies is an established care pathway in contemporary cardiology practice. The primary cardiomyopathies where genetic testing is indicated are hypertrophic, dilated, arrhythmogenic, and restrictive cardiomyopathies, with left ventricular noncompaction as a variant phenotype. Early identification and initiation of therapies in patients with inherited cardiomyopathies allow for targeting asymptomatic and presymptomatic patients in stages A and B of the American College of Cardiology/American Heart Association classification of heart failure. The current approach for genetic testing uses gene panel-based testing with the ability to extend to whole-exome and whole-genome sequencing in rare instances. The central components of genetic testing include defining the genetic basis of the diagnosis, providing prognostic information, and the ability to screen and risk-stratify relatives. Genetic testing for cardiomyopathies should be coordinated by a multidisciplinary team including adult and pediatric cardiologists, genetic counsellors, and geneticists, with access to expertise in cardiac imaging and electrophysiology. A pragmatic approach for addressing genetic variants of uncertain significance is important. In this review, we highlight the indications for genetic testing in the various cardiomyopathies, the value of early diagnosis and treatment, family screening, and the care process involved in genetic counselling and testing.

Epicardial Fat Distribution Assessed with Cardiac CT in Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy

Purpose To compare epicardial fat in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) with that in healthy subjects. Materials and Methods In this retrospective study, cardiac CT scans in 44 patients with ARVD/C (mean age, 39 years ± 12; 23 men) were compared with those in 45 control group participants between January 2008 and July 2015. Volumes of intrathoracic adipose tissue, mediastinal adipose tissue (MAT), and total epicardial adipose tissue (EAT) were quantified. EAT was subdivided into three regions-right ventricular (RV) EAT, left ventricular (LV) EAT, and peri-atrial EAT (atrial EAT)-and normalized to MAT for all regions. Logistic regression and receiver operating characteristic analysis were performed to evaluate the association between epicardial fat with the diagnosis of ARVD/C. Results Total EAT volume was higher in patients with ARVD/C than in healthy control group participants (median, 98 mL vs 76 mL, respectively; P = .04). Regionally, LV and RV EAT volumes were higher in patients with ARVD/C than in control group participants, most notably when indexed to MAT (median LV EAT index: 0.49 vs 0.15, respectively; median RV EAT index: 0.91 vs 0.52; P ˂ .0005 for both). The optimal cutoff for diagnosis of ARVD/C was an LV EAT index of 0.24, with a sensitivity and specificity of 91% and 71%, respectively. Atrial EAT volume and total intrathoracic adipose tissue volume were not different between groups. RV diameter showed a positive correlation with total EAT index and LV EAT index (r = 0.21, P = .05 and r = 0.33, P = .002, respectively). Conclusion Higher amounts of right ventricular and left ventricular epicardial fat are found in hearts with arrhythmogenic right ventricular dysplasia/cardiomyopathy, particularly adjacent to the left ventricle, which correlates with disease severity and helps differentiate patients from healthy subjects. © RSNA, 2018 Online supplemental material is available for this article.

Recent Advances in Understanding and Managing Cardiomyopathy

Cardiomyopathy is a disease of the heart muscle leading to abnormal structure or function in the absence of coronary artery disease, hypertension, or valvular or congenital heart disease. Currently, cardiomyopathy is the leading diagnosis of heart transplant patients worldwide. Incorporation of next-generation sequencing strategies will likely revolutionize genetic testing in cardiomyopathy. The use of patient-specific pluripotent stem cell-derived cardiomyocytes for disease modeling and therapeutic testing has opened a new avenue for precision medicine in cardiomyopathy. Stem cell therapy, gene therapy, interfering RNA, and small molecules are actively being evaluated in clinical trials.