254 research outputs found

    Study protocol to investigate the effects of testosterone therapy as an adjunct to exercise rehabilitation in hypogonadal males with chronic heart failure

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    BACKGROUND: Testosterone deficiency is a common occurrence in men with chronic heart failure (CHF) and may underpin features of advanced disease, including reduced skeletal muscle mass and fatigue. It is positively correlated with cardiac output and exercise capacity in patients with CHF, whereas a significant improvement in both these parameters has been observed following testosterone replacement therapy. Testosterone therapy has also been shown to reduce circulating levels of inflammatory markers, (TNF-α, sICAM-1 and sVCAM-1) in patients with established coronary artery disease and testosterone deficiency. This pilot study will assess the feasibility of a combined exercise rehabilitation and adjunctive testosterone therapy intervention for evoking improvements in exercise capacity, circulating inflammatory markers, cardiac and skeletal muscle function, indices of psychological health status and quality of life in hypogonadal males with chronic heart failure. METHODS/DESIGN: Following ethical approval, 36 patients will be randomly allocated to one of two groups: testosterone or placebo therapy during exercise rehabilitation. A combined programme of moderate intensity aerobic exercise and resistance (strength) training will be used. The primary outcome measure is exercise capacity, assessed using an incremental shuttle walk test. Secondary outcome measures include measures of peak oxygen uptake, cardiac function, lower-limb skeletal muscle contractile function and oxygenation during exercise, circulating inflammatory markers, psychological health status and quality of life. DISCUSSION: Exercise rehabilitation can safely increase exercise capacity in stable CHF patients but there is a need for studies which are aimed at evaluating the long-term effects of physical training on functional status, morbidity and mortality. This pilot study will provide valuable preliminary data on the efficacy of testosterone therapy as an adjunct to exercise rehabilitation on a range of functional, physiological and health-related outcomes in this patient population. Preliminary data will be used in the design of a large-scale randomised controlled trial, aimed at informing clinical practice with respect to optimisation of exercise rehabilitation in this patient group

    Acute Reverse Remodelling After Transcatheter Aortic Valve Implantation: A Link Between Myocardial Fibrosis and Left Ventricular Mass Regression

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    Background: Despite the wealth of data showing the positive effects on cardiac reverse remodelling in the long-term, the immediate effects of transcatheter aortic valve implantation (TAVI) on the left ventricle are yet to be comprehensively described using cardiovascular magnetic resonance imaging. Also, the link between myocardial fibrosis and acute left ventricular (LV) mass regression is unknown. Methods: Fifty-seven patients with severe aortic stenosis awaiting TAVI underwent paired cardiovascular magnetic resonance scans before and early after the procedure (4 [interquartile range, 3-5] days). LV mass, volume, and function were measured. Late gadolinium enhancement (LGE) imaging was performed to assess for the presence of and pattern of myocardial fibrosis. Results: After the procedure, 53 (95%) patients experienced an immediate (10.1 ± 7.1%) reduction in indexed LV mass (LVMi) from 76 ± 15.5 to 68.4 ± 14.7 g/m2 (P < 0.001). Those with no LGE experienced the greatest LVMi regression (13.9 ± 7.1%) compared with those with a midwall/focal fibrosis pattern LGE (7.4 ± 5.8%) and infarct pattern LGE (7.2 ± 7.0%; P = 0.005). There was no overall change in LV ejection fraction (LVEF; 55.1 ± 12.1% to 55.5 ± 10.9%; P = 0.867), however a significant improvement in LVEF was seen in those with abnormal (< 55%; n = 24; 42%) baseline LVEF (43.2 ± 8.9 to 46.7 ± 10.5%; P = 0.027). Baseline LVMi (P = 0.005) and myocardial fibrosis (P < 0.001) were strong independent predictors of early LVMi regression. Conclusions: LV reverse remodelling occurs immediately after TAVI, with significant LV mass regression in the total population and an improvement in LVEF in those with preexisting LV impairment. Those without myocardial fibrosis at baseline experience greater LV mass regression than those with fibrosis

    Welcoming low testosterone as a cardiovascular risk factor

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    Male hypogonadism now has a new spectrum of complications. They are mainly cardiometabolic in nature. Low serum testosterone levels are a risk factor for diabetes, metabolic syndrome, inflammation and dyslipidemia. These metabolic and inflammatory complications are not without consequences. Recent studies have shown low serum testosterone levels to be an independent risk factor of cardiovascular and all-cause mortality. It is time to welcome low serum testosterone levels as a cardiovascular risk factor

    Association between operator volume and mortality in primary percutaneous coronary intervention

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    Background There is a paucity of real-world data assessing the association of operator volumes and mortality specific to primary percutaneous coronary intervention (PPCI). Methods Demographic, clinical and outcome data for all patients undergoing PPCI in Leeds General Infirmary, UK, between 1 January 2009 and 31 December 2011, and 1 January 2013 and 31 December 2013, were obtained prospectively. Operator volumes were analysed according to annual operator PPCI volume (low volume: 1–54 PPCI per year; intermediate volume: 55–109 PPCI per year; high volume: ≥110 PPCI per year). Cox proportional hazards regression analyses were undertaken to investigate 30-day and 12-month all-cause mortality, adjusting for confounding factors. Results During this period, 4056 patients underwent PPCI, 3703 (91.3%) of whom were followed up for a minimum of 12 months. PPCI by low-volume operators was associated with significantly higher adjusted 30-day mortality (HR 1.48 (95% CI 1.05 to 2.08); p=0.02) compared with PPCI performed by high-volume operators, with no significant difference in adjusted 12-month mortality (HR 1.26 (95% CI 0.96 to 1.65); p=0.09). Comparisons between low-volume and intermediate-volume operators, and between intermediate and high-volume operators, showed no significant differences in 30-day and 12-month mortality. Conclusions Low operator volume is independently associated with higher probability of 30-day mortality compared with high operator volume, suggesting a volume–outcome relationship in PPCI at a threshold higher than current recommendations

    Multilayer Modelling of Lubricated Contacts: A New Approach Based on a Potential Field Description

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    A first integral approach, derived in an analogous fashion to Maxwell’s use of potential fields, is employed to investigate the flow characteristics, with a view to minimising friction, of shear-driven fluid motion between rigid surfaces in parallel alignment as a model for a lubricated joint, whether naturally occurring or engineered replacement. For a viscous bilayer arrangement comprised of immiscible liquids, it is shown how the flow and the shear stress along the separating interface is influenced by the mean thickness of the layers and the ratio of their respective viscosities. Considered in addition, is how the method can be extended for application to the more challenging problem of when one, or both, of the layers is a viscoelastic material
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