Aziz Guellich

Bio: Aziz Guellich is an academic researcher from French Institute of Health and Medical Research. The author has contributed to research in topics: Cardiac amyloidosis & Heart failure. The author has an hindex of 16, co-authored 37 publications receiving 1037 citations. Previous affiliations of Aziz Guellich include University of Paris-Sud.

Prevalence and clinical phenotype of hereditary transthyretin amyloid cardiomyopathy in patients with increased left ventricular wall thickness

Abstract: AIMS: Increased left ventricular wall thickness (LVWT) is a common finding in cardiology. It is not known how often hereditary transthyretin-related familial amyloid cardiomyopathy (mTTR-FAC) is responsible for LVWT. Several therapeutic modalities for mTTR-FAC are currently in clinical trials; thus, it is important to establish the prevalence of TTR mutations (mTTR) and the clinical characteristics of the patients with mTTR-FAC. METHODS AND RESULTS: In a prospective multicentre, cross-sectional study, the TTR gene was sequenced in 298 consecutive patients diagnosed with increased LVWT in primary cardiology clinics in France. Among the included patients, median (25-75th percentiles) age was 62 [50;74]; 74% were men; 23% were of African origin; and 36% were in NYHA Class III-IV. Median LVWT was 18 (16-21) mm. Seventeen (5.7%; 95% confidence interval [CI]: [3.4;9.0]) patients had mTTR of whom 15 (5.0%; 95% CI [2.9;8.2]) had mTTR-FAC. The most frequent mutations were V142I (n = 8), V50M (n = 2), and I127V (n = 2). All mTTR-FAC patients were older than 63 years with a median age of 74 [69;79]. Of the 15 patients with mTTR-FAC, 8 were of African descent while 7 were of European descent. In the African descendants, mTTR-FAC median age was 74 [72;79] vs. 55 [46;65] years in non-mTTR-FAC (P \textless 0.001). In an adjusted multivariate model, African origin, neuropathy, carpal tunnel syndrome, electrocardiogram (ECG) low voltage, and late gadolinium enhancement (LGE) at cardiac-magnetic resonance imaging were all independently associated with mTTR-FAC. CONCLUSION: Five per cent of patients diagnosed with hypertrophic cardiomyopathy have mTTR-FAC. Mutated transthyretin genetic screening is warranted in elderly subjects with increased LVWT, particularly, those of African descent with neuropathy, carpal tunnel syndrome, ECG low voltage, or LGE

Causes and Consequences of Longitudinal LV Dysfunction Assessed by 2D Strain Echocardiography in Cardiac Amyloidosis.

Abstract: Objectives The aim of this study was to compare left ventricular longitudinal strain (LS) evaluated by 2-dimensional echocardiography with cardiac magnetic resonance (CMR) in cardiac amyloidosis (CA), establish correlations between histological and imaging findings, and assess the prognostic usefulness of LS measurement and CMR. Background CA is a condition with a poor prognosis due chiefly to 3 forms of amyloidosis: light-chain amyloidosis (AL), hereditary transthyretin (M-TTR), and wild-type transthyretin (WT-TTR). Two-dimensional echocardiography measurement of LS has been reported to detect early left ventricular systolic dysfunction. The pathophysiological underpinnings, regional distribution, and prognostic significance of LS in CA are unclear. Methods All patients underwent echocardiography, and 53 underwent CMR. The native hearts of the 3 patients who received heart transplants were subjected to histological examination. For each of the 17 left ventricular segments in the American Heart Association model, we evaluated LS, late gadolinium enhancement (LGE) by CMR, and cardiac amyloid deposition. Univariate and multivariate analyses were performed at 6 months to identify variables associated with major adverse cardiac events (MACE). Results We studied 79 patients with CA; 26 had AL, 36 M-TTR, and 17 WT-TTR. Mean LS was −10 ± 4%. Both LS and amyloid deposits showed a basal-to-apical gradient. The mean LS and number of segments with LGE were similar across the 3 CA types. LS correlated with LGE and amyloid burden (r = 0.72). LGE was seen in the 6 basal segments in all WT-TTR patients. During the median follow-up of 11 months (range 4 to 17 months), 36 (46%) patients experienced MACE. Independent predictors of MACE were apical LS (cutoff, −14.5%), N-terminal pro–B-type natriuretic peptide (cutoff, 4,000 ng/l), and New York Heart Association functional class III to IV heart failure. Conclusions Basal-to-apical LS abnormalities are similar across CA types and reflect the amyloid burden. Apical LS independently predicts MACE.

Oxidative stress of myosin contributes to skeletal muscle dysfunction in rats with chronic heart failure

Abstract: Intrinsic muscle abnormalities affecting skeletal muscle are often reported during chronic heart failure (CHF). Because myosin is the molecular motor of force generation, we sought to determine whe...

Aortic stenosis and transthyretin cardiac amyloidosis: the chicken or the egg?

Abstract: Background Aortic stenosis (AS) and transthyretin cardiac amyloidosis (TTR-CA) are both frequent in elderly. The combination of these two diseases has never been investigated. Aims To describe patients with concomitant AS and TTR-CA. Methods Six cardiologic French centres identified retrospectively cases of patients with severe or moderate AS associated with TTR-CA hospitalized during the last 6 years. Results Sixteen patients were included. Mean ± SD age was 79 ± 6 years, 81% were men. Sixty per cent were NYHA III–IV, 31% had carpal tunnel syndrome, and 56% had atrial fibrillation. Median (Q1;Q4) NT-proBNP was 4382 (2425;4730) pg/mL and 91% had elevated cardiac troponin level. Eighty-eight per cent had severe AS ( n = 14/16), of whom 86% ( n = 12) had low-gradient AS. Mean ± SD interventricular septum thickness was 18 ± 4 mm. Mean left ventricular ejection fraction and global LS were 50 ± 13% and −7 ± 4%, respectively. Diagnosis of TTR-CA was histologically proven in 38%, and was based on strong cardiac uptake of the tracer at biphosphonate scintigraphy in the rest. Eighty-one per cent had wild-type TTR-CA ( n = 13), one had mutated Val122I and 19% did not had genetic test ( n = 3). Valve replacement was surgical in 63% and via transcatheter in 13%. Median follow-up in survivors was 33 (16;65) months. Mortality was of 44% ( n = 7) during the whole follow-up period. Conclusions Combination of AS and TTR-CA may occur in elderly patients particularly those with a low-flow low-gradient AS pattern and carries bad prognosis. Diagnosis of TTR-CA in AS is relevant to discuss specific treatment and management.

Usefulness of (99m)Tc-HMDP scintigraphy for the etiologic diagnosis and prognosis of cardiac amyloidosis.

Abstract: Background: Amyloidosis is characterized by extracellular deposits of insoluble proteins that cause tissue damage. The three main types are monoclonal light chain (AL), wild-type transthyretin (wt-TTR) and mutated transthyretin (m-TTR) amyloidosis. Cardiac amyloidosis (CA) raises diagnostic challenges.Objective: To assess the diagnostic accuracy of 99mTc-HMDP-scintigraphy for typing CA, differentiating CA from non-amyloid left ventricle hypertrophy (LVH), and predicting outcomes.Methods: 121 patients with suspected CA underwent 99mTc-HMDP-scintigraphy in addition to standard investigations.Results: CA was diagnosed in all AL (n = 14) and wt-TTR (n = 21). Among m-TTR (n = 34), 26 had CA, 4 neuropathy without CA and 4 were asymptomatic carriers. Of the 52 patients with non-amyloid heart disease, 37 had LVH and served as controls. 99mTc-HMDP cardiac uptake occurred in all wt-TTR, in m-TTR with CA except two and in one AL. A visual score ≥ 2 was 100% specific for diagnosing TTR-CA. Among TTR-CA, heart...

Exercise-induced oxidative stress: cellular mechanisms and impact on muscle force production

Abstract: The first suggestion that physical exercise results in free radical-mediated damage to tissues appeared in 1978, and the past three decades have resulted in a large growth of knowledge regarding exercise and oxidative stress. Although the sources of oxidant production during exercise continue to be debated, it is now well established that both resting and contracting skeletal muscles produce reactive oxygen species and reactive nitrogen species. Importantly, intense and prolonged exercise can result in oxidative damage to both proteins and lipids in the contracting myocytes. Furthermore, oxidants can modulate a number of cell signaling pathways and regulate the expression of multiple genes in eukaryotic cells. This oxidant-mediated change in gene expression involves changes at transcriptional, mRNA stability, and signal transduction levels. Furthermore, numerous products associated with oxidant-modulated genes have been identified and include antioxidant enzymes, stress proteins, DNA repair proteins, and mitochondrial electron transport proteins. Interestingly, low and physiological levels of reactive oxygen species are required for normal force production in skeletal muscle, but high levels of reactive oxygen species promote contractile dysfunction resulting in muscle weakness and fatigue. Ongoing research continues to probe the mechanisms by which oxidants influence skeletal muscle contractile properties and to explore interventions capable of protecting muscle from oxidant-mediated dysfunction.

Tafamidis Treatment for Patients with Transthyretin Amyloid Cardiomyopathy

Abstract: Background Transthyretin amyloid cardiomyopathy is caused by the deposition of transthyretin amyloid fibrils in the myocardium. The deposition occurs when wild-type or variant transthyretin becomes unstable and misfolds. Tafamidis binds to transthyretin, preventing tetramer dissociation and amyloidogenesis. Methods In a multicenter, international, double-blind, placebo-controlled, phase 3 trial, we randomly assigned 441 patients with transthyretin amyloid cardiomyopathy in a 2:1:2 ratio to receive 80 mg of tafamidis, 20 mg of tafamidis, or placebo for 30 months. In the primary analysis, we hierarchically assessed all-cause mortality, followed by frequency of cardiovascular-related hospitalizations according to the Finkelstein–Schoenfeld method. Key secondary end points were the change from baseline to month 30 for the 6-minute walk test and the score on the Kansas City Cardiomyopathy Questionnaire–Overall Summary (KCCQ-OS), in which higher scores indicate better health status. Results In the prim...

IS103 Loss of a gp130 Cardiac Muscle Cell Survival Pathway Is a Critical Event in the Onset of Heart Failure During Biomechanical Stress

Abstract: Biomechanical stress is a major stimulus for cardiac hypertrophy and the transition to heart failure. By generating mice that harbor a ventricular restricted knockout of the gp130 cytokine receptor via Cre-IoxP-mediated recombination, we demonstrate a critical role for a gp130-dependent myocyte survival pathway in the transition to heart failure. Such conditional mutant mice have normal cardiac structure and function, but during aortic pressure overload, these mice display rapid onset of dilated cardiomyopathy and massive induction of myocyte apoptosis versus the control mice that exhibit compensatory hypertrophy. Thus, cardiac myocyte apoptosis is a critical point in the transition between compensatory cardiac hypertrophy and heart failure. gp130-dependent cytokines may represent a novel therapeutic strategy for preventing in vivo heart failure.