Standard Therapy in Cardiac Amyloidosis: What is Known, What is "Gray".

Amyloidosis is a systemic disease due to the accumulation of misfolded amyloid fibrils that damage the heart and worsen the prognosis. Heart failure (HF), a condition frequently linked with an advanced stage of this disease, is the most prevalent clinical manifestation that leads to its diagnosis. However, due to the growing awareness of the occurrence of cardiac amyloidosis (CA), it is now possible to perform an early diagnosis and have a positive impact on its natural course. This study aims to highlight the most compelling issues concerning patients' clinical management with HF and CA.

Cardiac Magnetic Resonance Feature-Tracking Identifies Preclinical Abnormalities in Hypertrophic Cardiomyopathy Sarcomere Gene Mutation Carriers.

BACKGROUND: Assessing myocardial strain by cardiac magnetic resonance feature tracking (FT) has been found to be useful in patients with overt hypertrophic cardiomyopathy (HCM). Little is known, however, of its role in sarcomere gene mutation carriers without overt left ventricular hypertrophy (subclinical HCM). METHODS: Thirty-eight subclinical HCM subjects and 42 healthy volunteers were enrolled in this multicenter case-control study. They underwent a comprehensive cardiac magnetic resonance study. Two-dimensional global radial, circumferential, and longitudinal strain of the left ventricle (LV) were evaluated by FT analysis. RESULTS: The subclinical HCM sample was 41 (22-51) years old and 32% were men. FT analysis revealed a reduction in global radial strain (29±7.2 versus 47.9±7.4; P<0.0001), global circumferential strain (-17.3±2.6 -versus -20.8±7.4; P<0.0001) and global longitudinal strain (-16.9±2.4 versus -20.5±2.6; P<0.0001) in subclinical HCM compared with control subjects. The significant differences persisted when considering the 23 individuals free of all the structural and functional ECG and cardiac magnetic resonance abnormalities previously described. Receiver operating characteristic curve analyses showed that the differential diagnostic performances of FT in discriminating subclinical HCM from normal subjects were good to excellent (global radial strain with optimal cut-off value of 40.43%: AUC, 0.946 [95% CI, 0.93-1.00]; sensitivity 90.48%, specificity 94.44%; global circumferential strain with cut-off, -18.54%: AUC, 0.849 [95% CI, 0.76-0.94]; sensitivity, 88.10%; specificity, 72.22%; global longitudinal strain with cut-off, -19.06%: AUC, 0.843 [95% CI, 0.76-0.93]; sensitivity, 78.57%; specificity, 78.95%). Similar values were found for discriminating those subclinical HCM subjects without other phenotypic abnormalities from healthy volunteers (global radial strain with optimal cut-off 40.43%: AUC, 0.966 [95% CI, 0.92-1.00]; sensitivity, 90.48%; specificity, 95.45%; global circumferential strain with cut-off, -18.44%: AUC, 0.866 [95% CI, 0.76-0.96]; sensitivity, 92.86%; specificity, 77.27%; global longitudinal strain with cut-off, -17.32%: AUC, 0.838 [95% CI, 0.73-0.94]; sensitivity, 90.48%; specificity, 65.22%). CONCLUSIONS: Cardiac magnetic resonance FT-derived parameters are consistently lower in subclinical patients with HCM, and they could emerge as a good tool for discovering the disease during a preclinical phase.

Effects of sacubitril-valsartan on remodelling, fibrosis and mitochondria in a murine model of isoproterenol-induced left ventricular dysfunction.

BACKGROUND: Sacubitril/valsartan has been demonstrated to promote left ventricular (LV) reverse remodelling and improve outcomes in patients with heart failure (HF) with reduced ejection fraction (EF). Its molecular and tissue effects have not been fully elucidated yet, due to the paucity of preclinical studies, mostly based on ischaemic models. We aimed to evaluate the effects of sacubitril/valsartan on LV remodelling, myocardial fibrosis and mitochondrial biology in a murine model of non-ischaemic LV dysfunction. METHODS: Adult transgenic male mice with cardiac-specific hyperaldosteronism (AS mice) received subcutaneous isoproterenol injections to induce LV systolic dysfunction. After 7 days, mice were randomized to a 2-week treatment with saline (ISO-AS n = 15), valsartan (ISO + V n = 12) or sacubitril/valsartan (ISO + S/V n = 12). Echocardiography was performed at baseline, at day 7, and after each of the 2 weeks of treatment. After sacrifice at day 21, histological and immunochemical assays were performed. A control group of AS mice was also obtained (Ctrl-AS n = 8). RESULTS: Treatment with sacubitril/valsartan, but not with valsartan, induced a significant improvement in LVEF (p = 0.009 vs ISO-AS) and fractional shortening (p = 0.032 vs ISO-AS) after 2- week treatment. In both ISO + V and ISO + S/V groups, a trend toward reduction of the cardiac collagen 1/3 expression ratio was detected. ISO + V and ISO + S/V groups showed a significant recovery of mitochondrial morphology and inner membrane function meant for oxidative phosphorylation. CONCLUSION: In a murine model of non-ischaemic HF, sacubitril/valsartan proved to have beneficial effects on LV systolic function, and on cardiac energetics, by improving mitochondrial activity.

Clinical characteristics and outcome of end stage hypertrophic cardiomyopathy: Role of age and heart failure phenotypes.

BACKGROUND: A minority of patients with hypertrophic cardiomyopathy (HCM) presents advanced heart failure (HF) during their clinical course, in the context of left ventricular (LV) remodeling with reduced LV ejection fraction (LVEF), or of severe diastolic dysfunction without impaired LVEF. Aim of this study was to describe a multicentric end stage (ES) HCM population and analyze clinical course and outcome among its different phenotypes. METHODS: Data of all HCM patients from 7 Italian referral centres were retrospectively evaluated. ES was diagnosed in presence of: LVEF <50% (ES-rEF) or NYHA functional class ≥II with severe diastolic dysfunction (ES-pEF). Outcomes were: HCM-related and all-cause mortality; combined arrhythmic events; advanced HF treatments. RESULTS: Study population included 331 ES patients; 87% presented ES-rEF and 13% ES-pEF. At ES recognition, patients with ES-pEF were more commonly females, had more frequently NYHA III/IV, atrial fibrillation and greater maximal LV wall thickness. Over a median follow-up of 5.6 years, 83 (25%) patients died, 46 (15%) experienced arrhythmic events and (26%) 85 received advanced HF treatments. Incidence of HCM-related and all-cause mortality, and of combined arrhythmic events did not differ in ES-pEF and ES-rEF patients, but ES-pEF patients were less likely to receive advanced HF treatments. Older age at ES recognition was an independent predictor of increased HCM-related mortality (p = 0.01) and reduced access to advanced HF treatments (p < 0.0001). CONCLUSIONS: Two different HCM-ES phenotypes can be recognized, with ES-pEF showing distinctive features at ES recognition and receiving less frequently advanced HF treatments. Older age at ES recognition has a major impact on outcomes.

Transcatheter Ablation of Atrial Fibrillation in Patients With Hypertrophic Cardiomyopathy: A Multicenter Propensity Score-Based Analysis.

Background: The prognostic impact of catheter ablation (CA) of atrial fibrillation (AF) in hypertrophic cardiomyopathy (HCM) patients has not yet been satisfactorily elucidated. Objectives: The aim of the study was to assess the impact of CA of AF on clinical outcomes in a large cohort of HCM patients. Methods: In this retrospective multicenter study, 555 HCM patients with AF were enrolled, 140 undergoing CA and 415 receiving medical therapy. 1:1 propensity score matching led to the inclusion of 226 patients (113 medical group, 113 intervention group) in the final analysis. The primary outcome was a composite of all-cause mortality, heart transplant and acute heart failure exacerbations. Secondary outcomes included AF recurrence and transition to permanent AF. Additionally, an inverse probability weighted (IPW) model was examined. Results: At propensity score matching analysis, after a median follow-up of 58.1 months, the primary endpoint occurred in 29 (25.7%) patients in intervention group vs 42 (37.2%) in medical group (P = 0.9). Thromboembolic strokes and major arrhythmic events in intervention vs medical group were 9.7% vs 7.1% (P = 0.144) and 4.4 vs 8.0% (P = 0.779), respectively. Fewer patients in intervention vs medical group experienced AF recurrences (63.7% vs 84.1%, P = 0.001) and transition to permanent AF pattern (20.4% vs 33.6%, P = 0.026). IPW analysis showed consistent results. Severe complications related to CA were uncommon (0.7%). Conclusions: After 5 years of follow-up, CA did not improve major adverse cardiac outcomes in a large cohort of patients with HCM and AF. Nevertheless, CA seems to facilitate the maintenance of sinus rhythm and slow the progression to permanent AF, without significant safety concerns.