Iron overload in polytransfused patients without heart failure is associated with subclinical alterations of systolic left ventricular function using cardiovascular magnetic resonance tagging

BACKGROUND: It remains incompletely understood whether patients with transfusion related cardiac iron overload without signs of heart failure exhibit already subclinical alterations of systolic left ventricular (LV) dysfunction. Therefore we performed a comprehensive evaluation of systolic and diastolic cardiac function in such patients using tagged and phase-contrast CMR. METHODS: 19 patients requiring regular blood transfusions for chronic anemia and 8 healthy volunteers were investigated using cine, tagged, and phase-contrast and T2* CMR. LV ejection fraction, peak filling rate, end-systolic global midventricular systolic Eulerian radial thickening and shortening strains as well as left ventricular rotation and twist, mitral E and A wave velocity, and tissue e' wave and E/e' wave velocity ratio, as well as isovolumic relaxation time and E wave deceleration time were computed and compared to cardiac T2*. RESULTS: Patients without significant iron overload (T2* > 20 ms, n = 9) had similar parameters of systolic and diastolic function as normal controls, whereas patients with severe iron overload (T2* 20 ms) or normal controls. Patients with moderate iron overload (T2* 10-20 ms, n = 5), had preserved ejection fraction (59 ± 6%, p = NS vs. pts. with T2* > 20 ms and controls), but showed reduced maximal LV rotational twist (1.8 ± 0.4 degrees). The magnitude of reduction of LV twist (r = 0.64, p < 0.001), of LV ejection fraction (r = 0.44, p < 0.001), of peak radial thickening (r = 0.58, p < 0.001) and of systolic (r = 0.50, p < 0.05) and diastolic twist and untwist rate (r = -0.53, p < 0.001) in patients were directly correlated to the logarithm of cardiac T2*. CONCLUSION: Multiple transfused patients with normal ejection fraction and without heart failure have subclinical alterations of systolic and diastolic LV function in direct relation to the severity of cardiac iron overload. Among all parameters, left ventricular twist is affected earliest, and has the highest correlation to log (T2*), suggesting that this parameter might be used to follow systolic left ventricular function in patients with iron overload

Toekomstverkenning MIRA 2009 Wetenschappelijk rapport verzuring

In dit wetenschappelijk rapport worden de jaargemiddelde deposities, sectorale bijdragen en de overschrijding van kritische lasten voor verzuring bepaald in Vlaanderen, en dit voor twee MIRA-scenario’s, met name REF- scenario en EUR-scenario, voor de potentieel verzurende stoffen (NHx, NOy en SOx) voor de periode 2010 t.e.m. 2030. Het jaar 2006 werd beschouwd als referentiejaar. Er wordt ook bepaald wanneer herstel van bodemverzuring kan verwacht worden voor Vlaamse bosbodems

Diversity of Staphylococcus aureus Isolates in European Wildlife

Staphylococcus aureus is a well-known colonizer and cause of infection among animals and it has been described from numerous domestic and wild animal species. The aim of the present study was to investigate the molecular epidemiology of S. aureus in a convenience sample of European wildlife and to review what previously has been observed in the subject field. 124 S. aureus isolates were collected from wildlife in Germany, Austria and Sweden; they were characterized by DNA microarray hybridization and, for isolates with novel hybridization patterns, by multilocus sequence typing (MLST). The isolates were assigned to 29 clonal complexes and singleton sequence types (CC1, CC5, CC6, CC7, CC8, CC9, CC12, CC15, CC22, CC25, CC30, CC49, CC59, CC88, CC97, CC130, CC133, CC398, ST425, CC599, CC692, CC707, ST890, CC1956, ST2425, CC2671, ST2691, CC2767 and ST2963), some of which (ST2425, ST2691, ST2963) were not described previously. Resistance rates in wildlife strains were rather low and mecA-MRSA isolates were rare (n = 6). mecC-MRSA (n = 8) were identified from a fox, a fallow deer, hares and hedgehogs. The common cattle- associated lineages CC479 and CC705 were not detected in wildlife in the present study while, in contrast, a third common cattle lineage, CC97, was found to be common among cervids. No Staphylococcus argenteus or Staphylococcus schweitzeri-like isolates were found. Systematic studies are required to monitor the possible transmission of human- and livestock- associated S. aureus/MRSA to wildlife and vice versa as well as the possible transmission, by unprotected contact to animals. The prevalence of S. aureus/MRSA in wildlife as well as its population structures in different wildlife host species warrants further investigation

A single natural nucleotide mutation alters bacterial pathogen host tropism

The capacity of microbial pathogens to alter their host tropism leading to epidemics in distinct host species populations is a global public and veterinary health concern. To investigate the molecular basis of a bacterial host-switching event in a tractable host species, we traced the evolutionary trajectory of the common rabbit clone of Staphylococcus aureus. We report that it evolved through a likely human-to-rabbit host jump over 40 years ago and that only a single naturally occurring nucleotide mutation was required and sufficient to convert a human-specific S. aureus strain into one that could infect rabbits. Related mutations were identified at the same locus in other rabbit strains of distinct clonal origin, consistent with convergent evolution. This first report of a single mutation that was sufficient to alter the host tropism of a microorganism during its evolution highlights the capacity of some pathogens to readily expand into new host species populations

21e journée de cardiologie octobre 2013 : la maladie coronaire chez le diabétique: Qui depister?

Il existe aujourd’hui des outils efficaces pour faire le diagnostic de cardiopathie ischémique. Il est aussi établi que l’existence d’une ischémie myocardique silencieuse confère un moins bon pronostic surtout si les lésions coronaires sont multiples et proximales. Cependant, le screening systématique de la maladie coronaire ne s’accompagne pas d’une réduction des évènements cardiovasculaires chez le patient diabétique. Les lignes de conduites sont d’ailleurs inconsistantes voire parfois contradictoires lorsqu’il s’agit de faire des recommandations sur le screening de la maladie coronaire dans cette population. Une des explications selon laquelle le screening n’impacte pas le pronostic du patient diabétique est que la prévalence du « patient diabétique asymptomatique porteur de lésions multiples et proximales » est faible et qu’il est donc nécessaire d’évaluer un très grand nombre de patients pour influencer le pronostic. Une autre explication vient peut-être du fait que le traitement proposé (la revascularisation myocardique par exemple) n’est peut-être pas assez efficace (ou plus efficace que le traitement médical optimal) pour prévenir les évènements. Enfin, une autre hypothèse consiste à penser que le traitement de revascularisation n’est pas proposé systématiquement ou n’est pas proposé aux patients qui en bénéficieraient le plus. Dans cette revue, nous reverrons brièvement la littérature qui concerne cette difficile question du screening de la maladie coronaire chez le patient diabétique et nous essayerons de dégager quelques recommandations

Quand le sport est prescrit après un problème cardiaque. La réadaptation cardiaque

Les effets bénéfiques de l’activité physique sur le système cardiovasculaire sont démontrés. Les changements physiologiques induits par une activité sportive régulière participent à une meilleure qualité de vie du patient coronarien ou insuffisant cardiaque. Un programme de revalidation cardiaque bien conduit s’accompagne également d’une diminution de la mortalité globale dans ces deux populations de patients. Il appartient à chaque thérapeute d’en faire la promotion auprès des patients qui devraient en bénéficier.[When sports activities are prescribed in the aftermath of a cardiac event. Cardiac Rehabilitation] The beneficial effects of physical activity on the cardiovascular system have been well demonstrated, and the physiological changes induced by regular exercise have been shown to improve quality of life in coronary or heart failure patients. In addition, cardiac rehabilitation has been proven to be associated with decreased overall mortality in the two patient populations. Every therapist should therefore actively promote the participation in a cardiac rehabilitation program for those patients likely to benefit from such a progra

Quel traitement pour l’angor stable ?

L’angor stable est un syndrome clinique caractérisé par un inconfort dans la poitrine, les mâchoires, les épaules, le dos ou les bras, qui apparait typiquement à l’effort ou au stress. C’est un syndrome fréquent. Sa prise en charge thérapeutique dépend avant tout du pronostic individuel du patient. Le pronostic dépend de facteurs cliniques et de l’imagerie non invasive. La base du traitement repose sur la prise en charge des facteurs de risque cardiovasculaire et sur le traitement pharmacologique. Certains patients bénéficieront également d’une revascularisation percutanée ou chirurgicale