Arrhythmogenic Cardiomyopathy: A Disease or Merely a Phenotype?

Arrhythmogenic cardiomyopathy (AC) is a clinical entity that has evolved conceptually over the past 30 years. Advances in cardiac imaging and the introduction of genetics into everyday practice have revealed that AC comprises multiple phenotypes that are dependent on genetic or acquired factors. In this study, the authors summarise the approach to the identification of the AC phenotype and its underlying causes. They believe that AC represents a paradigm for personalised medicine in cardiology and that better stratification of the disease will enhance the development of mechanism-based treatments

Management of arrhythmogenic right ventricular cardiomyopathy

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a disease characterised by fibrofatty replacement of the ventricular myocardium due to specific mutations, leading to ventricular arrhythmias and sudden cardiac death. Treating this condition can be challenging due to progressive fibrosis, phenotypic variations and small patient cohorts limiting the feasibility of conducting meaningful clinical trials. Although widely used, the evidence base for anti-arrhythmic drugs is limited. Beta-blockers are theoretically sound, yet their efficacy in reducing arrhythmic risk is not robust. Additionally, the impact of sotalol and amiodarone is inconsistent with studies reporting contradictory results. Emerging evidence suggests that combining flecainide and bisoprolol may be efficacious.Radiofrequency ablation has shown some potential in disrupting ventricular tachycardia circuits, with combined endo and epicardial ablation yielding better results which could be considered at the index procedure. In addition, stereotactic radiotherapy may be a future option that can decrease arrhythmias beyond simple scar formation by altering levels of Nav1.5 channels, Connexin 43 and Wnt signalling, potentially modifying myocardial fibrosis.Future therapies, such as adenoviruses and GSk3b modulation, are still in early-stage research. While implantable cardioverter-defibrillator implantation is a key intervention for reducing arrhythmic death, the risks of inappropriate shocks and device complications must be carefully considered

Almanac 2011: Cardiomyopathies. The national society journals present selected research that has driven recent advances in clinical cardiology

As we approach the end of 2011 it is clear that the next few years are going to be dominated by the application of new high throughput genetic screening techniques, capable of screening the entire exome or indeed genome. Understanding the data generated by these techniques will require new and equally sophisticated analysis of large and complex datasets, using a systems biology approach with deeper phenotyping and advanced modelling techniques that have the flexibility for continuous update, refinement with discovery of new knowledge. Exciting new developments that may also transform cardiomyopathy research include those of infrastructure and organisation (multi-centre collaborations) and spin-offs from the field of regenerative medicine research. For clinical researchers that translate this information to the clinic the focus will however remain the same; namely improvement of quality and quantity of life

Right ventricular function is a predictor for sustained ventricular tachycardia requiring anti-tachycardic pacing in arrhythmogenic ventricular cardiomyopathy: insight into transvenous vs. subcutaneous implantable cardioverter defibrillator insertion

AIMS: Arrhythmogenic right ventricular cardiomyopathy (ARVC) patients develop ventricular arrhythmias (VAs) responsive to anti-tachycardia pacing (ATP). However, VA episodes have not been characterized in accordance with the device therapy, and with the emergence of the subcutaneous implantable cardioverter defibrillator (S-ICD), the appropriate device prescription in ARVC remains unclear. Study aim was to characterize VA events in ARVC patients during follow-up in accordance with device therapy and elicit if certain parameters are predictive of specific VA events. METHODS AND RESULTS: This was a retrospective single-centre study utilizing prospectively collated registry data of ARVC patients with ICDs. Forty-six patients were included [54.0 ± 12.1 years old and 20 (43.5%) secondary prevention devices]. During a follow-up of 12.1 ± 6.9 years, 31 (67.4%) patients had VA events [n = 2, 6.5% ventricular fibrillation (VF), n = 14], 45.2% VT falling in VF zone resulting in ICD shock(s), n = 10, 32.3% VT resulting in ATP, and n = 5, 16.1% patients had both VT resulting in ATP and ICD shock(s). Lead failure rates were high (11/46, 23.9%). ATP was successful in 34.5% of patients. Severely impaired right ventricular (RV) function was an independent predictor of VT resulting in ATP (hazard ratio 16.80, 95% confidence interval 3.74–75.2; P < 0.001) with a high predictive accuracy (area under the curve 0.88, 95%CI 0.76–1.00; P < 0.001). CONCLUSION: VA event rates are high in ARVC patients with a majority having VT falling in the VF zone resulting in ICD shock(s). S-ICDs could be of benefit in most patients with ARVC with the absence of severely impaired RV function which has the potential to avoid consequences of the high burden of lead failure

Almanac 2014: Cardiomyopathies

Kardiomiopatije su bolesti miokarda koje se ne mogu objasniti abnormalnim uvjetima punjenja niti promjenama koronarnih arterija. One se klasifi ciraju u više morfoloških i funkcionalnih fenotipova čiji uzrok mogu biti genetički i negenetički mehanizmi. Dominantne teme u radovima objavljenima u razdoblju 2012.-2013. slične su onima navedenima u Almanahu 2011.: uporaba (i interpretacija) genetskog testiranja, razvoj i primjena novih neinvazivnih tehnika slikovne dijagnostike te uporaba serumskih biomarkera u procesu dijagnoze i za prognozu. Važna inovacija od posljednjeg Almanaha jest razvoj sofisticiranijih modela za predviđanje neželjenih kliničkih događaja.Cardiomyopathies are myocardial disorders that are not explained by abnormal loading conditions and coronary artery disease. They are classified into a number of morphological and functional phenotypes that can be caused by genetic and non-genetic mechanisms. The dominant themes in papers published in 2012–2013 are similar to those reported in Almanac 2011, namely, the use (and interpretation) of genetic testing, development and application of novel non-invasive imaging techniques and use of serum biomarkers for diagnosis and prognosis. An important innovation since the last Almanac is the development of more sophisticated models for predicting adverse clinical events

screening for transthyretin amyloid cardiomyopathy in everyday practice

Abstract Transthyretin amyloid cardiomyopathy (ATTR-CM) is a life-threatening, progressive, infiltrative disease caused by the deposition of transthyretin amyloid fibrils in the heart, and can often be overlooked as a common cause of heart failure. Delayed diagnosis due to lack of disease awareness and misdiagnosis results in a poorer prognosis. Early accurate diagnosis is therefore key to improving patient outcomes, particularly in the context of both the recent approval of tafamidis in some countries (including the United States) for the treatment of ATTR-CM, and of other promising therapies under development. With the availability of scintigraphy as an inexpensive, noninvasive diagnostic tool, the rationale to screen for ATTR-CM in high-risk populations of patients is increasingly warranted. Here the authors propose a framework of clinical scenarios in which screening for ATTR-CM is recommended, as well as diagnostic "red flags" that can assist in its diagnosis among the wider population of patients with heart failure

Role of serum N-terminal pro-brain natriuretic peptide measurement in diagnosis of cardiac involvement in patients with anderson-fabry disease

Enzyme replacement therapy has the potential to delay or reverse adverse cardiac remodeling in Anderson-Fabry disease (AFD); however, the current indications for enzyme replacement therapy rely on detecting relatively advanced features of the disease. We aimed to determine the relation between the serum N-terminal pro-brain natriuretic peptide (NT-proBNP) concentration and cardiac abnormalities in patients with AFD. We hypothesized that it might help to detect early disease. NT-proBNP was measured under at rest conditions in 117 patients with AFD (age 48 ± 15 years, 46.2% men). All patients underwent clinical evaluation with electrocardiography and echocardiography. The median NT-proBNP concentration was 24 pmol/L (range <5 to 6,059). Of the 117 patients, 67 (57%) had elevated, age-corrected, NT-proBNP levels. In the 56 patients (48%) with normal echocardiographic findings, the NT-proBNP levels were greater than the age-predicted cutoffs in 10 of 25 patients with abnormal electrocardiographic findings and 3 of 31 patients with normal electrocardiographic findings (p <0.05). On multiple regression analysis, age, creatinine, left atrial volume index, E/Ea, and the presence of abnormal electrocardiographic findings were independently associated with log NT-proBNP (R(2) = 0.67, p <0.05). In conclusion, NT-proBNP concentrations were elevated in patients with AFD and early cardiac involvement, suggesting its measurement could assist in decisions regarding the timing of enzyme replacement therapy