65 research outputs found
Reduced functional measure of cardiovascular reserve predicts admission to critical care unit following kidney transplantation
Background: There is currently no effective preoperative assessment for patients undergoing kidney transplantation that is
able to identify those at high perioperative risk requiring admission to critical care unit (CCU). We sought to determine if
functional measures of cardiovascular reserve, in particular the anaerobic threshold (VO2AT) could identify these patients.
Methods: Adult patients were assessed within 4 weeks prior to kidney transplantation in a University hospital with a 37-bed
CCU, between April 2010 and June 2012. Cardiopulmonary exercise testing (CPET), echocardiography and arterial
applanation tonometry were performed.
Results: There were 70 participants (age 41.7614.5 years, 60% male, 91.4% living donor kidney recipients, 23.4% were
desensitized). 14 patients (20%) required escalation of care from the ward to CCU following transplantation. Reduced
anaerobic threshold (VO2AT) was the most significant predictor, independently (OR = 0.43; 95% CI 0.27–0.68; p,0.001) and
in the multivariate logistic regression analysis (adjusted OR = 0.26; 95% CI 0.12–0.59; p = 0.001). The area under the receiveroperating-
characteristic curve was 0.93, based on a risk prediction model that incorporated VO2AT, body mass index and
desensitization status. Neither echocardiographic nor measures of aortic compliance were significantly associated with CCU
admission.
Conclusions: To our knowledge, this is the first prospective observational study to demonstrate the usefulness of CPET as a
preoperative risk stratification tool for patients undergoing kidney transplantation. The study suggests that VO2AT has the
potential to predict perioperative morbidity in kidney transplant recipients
Erectile dysfunction and heart failure: the role of phosphodiesterase type 5 inhibitors
The phosphodiesterase type 5 (PDE-5) inhibitors are effective in treating erectile dysfunction (ED). ED and heart failure (HF) share similar risk factors, and commonly present together. This association has led to questions ranging from the safety and efficacy of PDE-5 inhibitors in HF patients to a possible role for this class of medication to treat HF patients with or without ED. In addition to endothelial dysfunction, there are causes of ED specific to patients with HF including low exercise tolerance, depression and HF medications. Before treating HF patients with PDE-5 inhibitors, patients should be assessed for their risk of a cardiac event during sexual activity. PDE-5 inhibitors are safe and effective in treating ED in HF patients. An improvement in erectile function by PDE-5 inhibitors was associated with an improvement in quality of life and reduction in depression. Several studies demonstrated the effect of PDE-5 inhibitors on HF per se. PDE-5 inhibitors improved endothelial dysfunction, increased exercise tolerance, decreased pulmonary vascular resistance and pulmonary artery pressure, and increased cardiac index. Several mechanisms whereby PDE-5 inhibitors improve HF have been proposed. PDE-5 inhibitors already have a role in treating primary pulmonary hypertension; however additional studies are needed to determine if they will become a standard therapy for HF patients
Current clinical applications of spectral tissue Doppler echocardiography (E/E' ratio) as a noninvasive surrogate for left ventricular diastolic pressures in the diagnosis of heart failure with preserved left ventricular systolic function
Congestive heart failure with preserved left ventricular systolic function has emerged as a growing epidemic medical syndrome in developed countries, which is characterized by high morbidity and mortality rates. Rapid and accurate diagnosis of this condition is essential for optimizing the therapeutic management. The diagnosis of congestive heart failure is challenging in patients presenting without obvious left ventricular systolic dysfunction and additional diagnostic information is most commonly required in this setting. Comprehensive Doppler echocardiography is the single most useful diagnostic test recommended by the ESC and ACC/AHA guidelines for assessing left ventricular ejection fraction and cardiac abnormalities in patients with suspected congestive heart failure, and non-invasively determined basal or exercise-induced pulmonary capillary hypertension is likely to become a hallmark of congestive heart failure in symptomatic patients with preserved left ventricular systolic function. The present review will focus on the current clinical applications of spectral tissue Doppler echocardiography used as a reliable noninvasive surrogate for left ventricular diastolic pressures at rest as well as during exercise in the diagnosis of heart failure with preserved left ventricular systolic function. Chronic congestive heart failure, a disease of exercise, and acute heart failure syndromes are characterized by specific pathophysiologic and diagnostic issues, and these two clinical presentations will be discussed separately
Impact of inactivity and exercise on the vasculature in humans
The effects of inactivity and exercise training on established and novel cardiovascular risk factors are relatively modest and do not account for the impact of inactivity and exercise on vascular risk. We examine evidence that inactivity and exercise have direct effects on both vasculature function and structure in humans. Physical deconditioning is associated with enhanced vasoconstrictor tone and has profound and rapid effects on arterial remodelling in both large and smaller arteries. Evidence for an effect of deconditioning on vasodilator function is less consistent. Studies of the impact of exercise training suggest that both functional and structural remodelling adaptations occur and that the magnitude and time-course of these changes depends upon training duration and intensity and the vessel beds involved. Inactivity and exercise have direct “vascular deconditioning and conditioning” effects which likely modify cardiovascular risk
TTF-1 regulates α5 nicotinic acetylcholine receptor (nAChR) subunits in proximal and distal lung epithelium
Effects of lifestyle intervention in BRCA1/2 mutation carriers on nutrition, BMI, and physical fitness (LIBRE study): study protocol for a randomized controlled trial
Pulmonary hypertension in heart failure with preserved ejection fraction: a target of phosphodiesterase-5 inhibition in a 1-year study
BACKGROUND-: The prevalence of heart failure with preserved ejection fraction is increasing. The prognosis worsens with pulmonary hypertension and right ventricular (RV) failure development. We targeted pulmonary hypertension and RV burden with the phosphodiesterase-5 inhibitor sildenafil. METHODS AND RESULTS-: Forty-four patients with heart failure with preserved ejection fraction (heart failure signs and symptoms, diastolic dysfunction, ejection fraction 6550%, and pulmonary artery systolic pressure >40 mm Hg) were randomly assigned to placebo or sildenafil (50 mg thrice per day). At 6 months, there was no improvement with placebo, but sildenafil mediated significant improvements in mean pulmonary artery pressure (-42.0\ub113.0%) and RV function, as suggested by leftward shift of the RV Frank-Starling relationship, increased tricuspid annular systolic excursion (+69.0\ub119.0%) and ejection rate (+17.0\ub18.3%), and reduced right atrial pressure (-54.0\ub17.2%). These effects may have resulted from changes within the lung (reduced lung water content and improved alveolar-capillary gas conductance, +15.8\ub14.5%), the pulmonary vasculature (arteriolar resistance,-71.0\ub18.2%), and left-sided cardiac function (wedge pulmonary pressure,-15.7\ub13.1%; cardiac index, +6.0\ub10.9%; deceleration time,-13.0\ub11.9%; isovolumic relaxation time,-14.0\ub11.7%; septal mitral annulus velocity,-76.4\ub19.2%). Results were similar at 12 months. CONCLUSIONS-: The multifaceted response to phosphodiesterase-5 inhibition in heart failure with preserved ejection fraction includes improvement in pulmonary pressure and vasomotility, RV function and dimension, left ventricular relaxation and distensibility (structural changes and/or ventricular interdependence), and lung interstitial water metabolism (wedge pulmonary pressure decrease improving hydrostatic balance and right atrial pressure reduction facilitating lung lymphatic drainage). These results enhance our understanding of heart failure with preserved ejection fraction and offer new directions for therapy
Insulin ameliorates exercise ventilatory efficiency and oxygen uptake in patients with heart failure-type 2 diabetes comorbidity
OBJECTIVES: This study sought to test whether insulin improves exercise ventilatory efficiency, (VE/VCO 2 slope) and oxygen uptake at peak exercise (peak VO 2) in patients with type 2 diabetes-heart failure (HF) comorbidity. BACKGROUND: In type 2 diabetes-HF comorbidity, depression of alveolar-capillary diffusion (DL CO) correlates with deterioration of exercise VE/VCO 2 slope and peak VO 2. Insulin potentiates DL CO in these patients. METHODS: Exercise ventilatory effidency and peak VO 2 (cycle ergometry ramp protocol), as well as DL CO at rest and its subdivisions (membrane conductance [D M] and pulmonary capillary blood volume [V C]) were assessed in 18 patients with type 2 diabetes-HF comorbidity at baseline and after 50 ml of saline + regular insulin (10 IU), or saline, was infused on consecutive days, according to a random crossover design. Glycemia was kept at pre-insulin level for the experiment duration. RESULTS: Baseline DL CO, D M, peak VO 2, and VE/VCO 2 slope were compromised in these patients. At measurements performed in the 60 min after infusions, compared with at baseline, saline was ineffective, whereas insulin augmented peak VO 2 (+13.5%) and lowered VE/VCO 2 slope (-18%), and also increased time to anaerobic threshold (+29.4%), maximal O 2 pulse (+12.3%), aerobic efficiency (+21.2%), DL CO (+12.5%), and D M (+21.6%), despite a reduction in V C (-16.3%); insulin did not vary cardiac index and eiecdon fraction at rest. Changes in peak VO 2 and VE/VCO 2 slope (r = 0.67, p = 0.002; r = -0.73, p < 0.001, respectively) correlated with those in DL CO. These responses were unrelated to glycohemoglobin and baseline fasting blood sugar. They were persistent at 6 h after insulin infusion, and were undetectable at 24 h. CONCLUSIONS: In diabetes-HF comorbidity, insulin causes a prolonged improvement in physical performance through activation of multiple factors, among which facilitation of gas conductance seems to be predominant
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