Bacteremia after upper gastrointestinal endoscopy.

During 24 months, 200 upper gastrointestinal endoscopies were performed on 193 patients. Blood cultures were obtained before and five and 30 minutes after the procedure using thiol (50 ml) and trypticase soy broth (100 ml) media. The mean endoscopic time was 34 minutes. Sixteen patients developed bacteremia (8%). Twelve groups of microorganisms were detected in positive blood cultures: Streptococcus (5 species), Lactobacillus sp, Veillonella alcalescens, Staphylococcus aureus, Staph epidermidis, Propioni-bacterium acnes, Corynebacterium acnes, and Bacillus subtilis. Seven patients had positive blood cultures at five and 30 minutes, eight at five minutes, and one at 30 minutes only. There was no clear correlation of bacteremia with the age or previous history of the patient, biopsy, active bleeding, endoscopic time, or findings. A follow-up study of all patients for six months to two years indicated no complications related to endoscopy and/or bacteremia.     

Vascular endothelial growth factor, left ventricular dysfunction and mortality in hemodialysis patients

OBJECTIVES: Vascular endothelial growth factor induces nitric oxide-dependent angiogenic effects and participates in the inflammatory response. This cytokine is over-expressed in the myocardium in experimental models of pressure overload and renal mass ablation, and vascular endothelial growth factor is increased in end-stage renal disease. We investigated the relationship between vascular endothelial growth factor, left ventricular function (by midwall fractional shortening) and mortality in a prospective cohort study in 228 hemodialysis patients. RESULTS: Serum vascular endothelial growth factor concentration was associated directly with interleukin-6 and tumor necrosis factor-alpha (P < 0.01) and inversely with albumin (P = 0.007) but was independent of the endogenous inhibitor of nitric oxide synthesis, asymmetric dimethylarginine. Vascular endothelial growth factor was inversely related with midwall fractional shortening (P = 0.002) and predicted mortality (P = 0.02). In multivariate analyses testing the involvement of this angiogenic cytokine in left ventricular dysfunction and death, these links remained substantially unmodified after adjustment for Framingham risk factors, risk factors peculiar to end-stage renal disease (Hb, Ca, P) and previous cardiovascular complications. However, these links became weaker and not significant when biomarkers of inflammation and asymmetric dimethylarginine were sequentially introduced into the multivariate models. In crude and adjusted analyses, left ventricular function was lowest in patients who displayed both high vascular endothelial growth factor and high asymmetric dimethylarginine, intermediate in patients with either high vascular endothelial growth factor or high asymmetric dimethylarginine and highest in those with low asymmetric dimethylarginine and low vascular endothelial growth factor (P = 0.001). CONCLUSION: Vascular endothelial growth factor is associated with left ventricular systolic dysfunction and mortality in hemodialysis patients. Vascular endothelial growth factor appears to be in the pathway whereby inflammation and nitric oxide inhibition lead to cardiomyopathy and death in hemodialysis patients.     

Diagnostic value of troponin T for alterations in left ventricular mass and function in dialysis patients

BACKGROUND: Cardiac troponin T (cTnT) is related to left ventricular (LV) mass in patients with end-stage renal disease (ESRD). Furthermore, cTnT reflects the severity of systolic dysfunction in patients with heart diseases. We tested the diagnostic value of cTnT for left ventricular hypertrophy (LVH) and LV systolic dysfunction in a large group of clinically stable hemodialysis patients without heart failure. RESULTS: CTnT was significantly (P < 0.001) higher in patients with LVH than in those with normal LV mass. In a multiple logistic regression model, adjusting for potential confounders (including cardiac ischemia), systolic pressure and cTnT (both P = 0.003) were the strongest correlates of LVH. Similarly, cTnT was significantly higher (P = 0.005) in patients with systolic dysfunction than in those with normal LV function and in a multiple logistic regression model cTnT ranked as the second independent correlate of this alteration after male sex. Serum cTnT had a high positive prediction value for the diagnosis of LVH (87%) but its negative prediction value was relatively low (44%). The positive predictive value of cTnT for LV dysfunction was low (25%) while its negative predictive value was high (93%). A combined analysis including systolic pressure (for the diagnosis of LVH) and sex (for the diagnosis of LV systolic dysfunction) augmented the diagnostic estimates to an important extent (95% positive prediction value for LVH and 98% negative prediction value for LV systolic dysfunction). CONCLUSIONS: CTnT has a fairly good diagnostic potential for the identification of LVH and for the exclusion of LV systolic dysfunction in patients with ESRD without heart failure. This marker may be useful for the screening of alterations in LV mass and function in clinically stable hemodialysis patients.     

Left ventricular mass monitoring in the follow-up of dialysis patients: prognostic value of left ventricular hypertrophy progression

BACKGROUND: Regression of left ventricular hypertrophy (LVH) in the setting of a well-planned intervention study has been associated with longer survival in hemodialysis patients. Whether changes in left ventricular mass (LVM) in clinical practice predict survival and cardiovascular events in these patients is still unknown. METHODS: In a prospective study in 161 hemodialysis patients we tested the prognostic value of changes in LVM on survival and incident cardiovascular events. Echocardiography was performed twice, 18 +/- 2 SD months apart. Changes in LVM occurring between the first and the second echocardiographic study were then used to predict mortality and cardiovascular events during the ensuing 29 +/- 13 months. The prognostic value of LVM changes was tested in a multivariate Cox's model with LVM index (LVMI) [expressed as LVM/height(2.71)], included as a covariate to control for regression to the mean. RESULTS: The rate of increase of LVMI was significantly (P= 0.029) higher in patients with incident cardiovascular events than in those without such events. Accordingly, cardiovascular event-free survival in patients with changes in LVMI below the 25th percentile was significantly (P= 0.004) higher than in those with changes above the 75th percentile. In a multiple Cox regression analysis, including age, diabetes, smoking, homocysteine, 1 g/m(2.7)/month increase in LVMI was associated with a 62% increase in the incident risk of fatal and nonfatal cardiovascular events [hazard ratio 1.62 (95% CI 1.13-2.33), P= 0.009]. CONCLUSION: Changes in LVMI have an independent prognostic value for cardiovascular events and provide scientific support to the use of repeated echocardiographic studies for monitoring cardiovascular risk in dialysis patients.     

Treadmill exercise-induced release of endothelin-1 in patients with peripheral arterial occlusive disease at Fontaine stage IIb.

BACKGROUND: Endothelin-1 (ET-1) is an endothelial vasoconstrictor mitogenic peptide which is thought to be a marker of endothelial damage and a potential participant in the pathophysiological processes of the development of atherosclerotic lesions and disease states associated with vasoconstriction and vasospasm. METHODS: To investigate the endothelin-1 release in response to dynamic exercise in patients with peripheral arterial occlusive disease (PAOD), plasma concentrations were determined by radioimmunoassay in 16 patients (14 men, 2 women, mean age 56.2 +/- 8.1 years) with peripheral arterial occlusive disease at Fontaine stage IIb and in 10 control subjects (8 men, 2 women, mean age 58.1 +/- 7.2 years) in normal health during treadmill testing (slope 5%, speed 3 km/hr). Blood samples were collected at rest from an antecubital vein, at the onset of claudication pain, and 10 minutes after exercise. RESULTS: Mean plasma endothelin-concentrations during the stress test increased significantly in the patients with arterial disease, rising from basal values of 4.4 +/- 0.6 pmol/L to values of 8.9 +/- 0.7 pmol/L at the end of the test (p < 0.0001), whereas it did not change significantly in control subjects (rising from 2.6 +/- 0.4 pmol/L to 2.7 +/- 0.5 pmol/L). Further, plasma endothelin- in the patients with arterial disease was at all times higher than in the control subjects (p < 0.0001). CONCLUSIONS: In conclusion, this study shows that in patients with peripheral arterial occlusive disease, plasma endothelin-1 increases after treadmill exercise performed until claudication pain supervenes. Raised endothelin-1 could be a marker of ischaemic acute endothelial damage and/or could contribute to increase the vascular resistance in ischaemic limbs of these patients during dynamic exercise by promoting arterial/arteriolar vasoconstriction or vasospasm.     

Phosphodiesterase type 5 inhibition reverses impaired forearm exercise-induced vasodilatation in hypertensive patients

OBJECTIVE: Established hypertension is characterized by increased peripheral vascular resistance and endothelial dysfunction, features that may underlie the reduced exercise-induced vasodilatation seen in hypertensive patients. Sildenafil citrate is a phosphodiesterase type 5 (PDE5) inhibitor used clinically for the treatment of male erectile dysfunction. Its vasodilating properties are due to the inhibition of cyclic guanosine monophosphate (cGMP) breakdown and prolongation of the signalling actions of the nitric oxide (NO)-cGMP pathway in vascular smooth muscle cells. Sildenafil has beneficial effects on endothelial function and exercise tolerance in congestive heart failure and pulmonary hypertension, and we hypothesized that it would improve exercise-induced vasodilatation in hypertensive patients. METHODS AND RESULTS: Ten hypertensive patients and ten matched normotensive subjects were studied in a three-way, randomized, single-blind and placebo-controlled study. On each study day, forearm blood flow (FBF) responses to handgrip exercise were assessed before and after intra-arterial (brachial) infusion of sildenafil, verapamil (a control, cGMP-independent vasodilator), and saline (placebo). Preinfusion exercise-induced vasodilatation was significantly reduced in hypertensive patients compared to normotensive controls. Sildenafil and verapamil infusions both caused a similar increase in baseline FBF. However, while verapamil did not affect the vasodilator response to handgrip exercise in either group, sildenafil substantially enhanced this response in hypertensive patients, but not in normotensive subjects. CONCLUSIONS: Our data suggest that sildenafil, through an increase in cGMP levels in the vasculature, substantially and selectively improves the vasodilator response to handgrip exercise in hypertensive patients. These findings represent an essential first step in support of further studies exploring the potentially beneficial effects of PDE5 inhibition on impaired exercise capacity in hypertension.     

Vitamin D receptor (VDR) gene polymorphism is associated with left ventricular (LV) mass and predicts left ventricular hypertrophy (LVH) progression in end‐stage renal disease (ESRD) patients

Left ventricular hypertrophy (LVH) is a strong cardiovascular risk marker in end‐stage renal disease (ESRD) patients. Vitamin D deficiency and/or disturbed vitamin D signaling has been implicated in LVH in experimental models. Because the BsmI vitamin D receptor VDR gene polymorphism may alter VDR function, we performed a cross‐sectional and longitudinal study in a cohort of 182 dialysis patients to investigate (1) the relationship between BsmI VDR gene polymorphism and left ventricular mass index (LVMI) measured by echocardiography and (2) the predictive power of this polymorphism for progression in LVH over a 18 ± 2 months of follow‐up. As a reference group, we used 175 healthy subjects matched to the study population as for age and sex. The distribution of BsmI genotypes did not significantly deviate from Hardy‐Weinberg equilibrium either in patients or in the control group of healthy subjects. The frequency of the B allele of BsmI polymorphism (40.4%) in dialysis patients was similar to that of healthy control subjects (38.6%), and the number of B alleles was directly related to LVMI (r = 0.20, P = .007). This relationship remained robust (β = 0.19, P = .006) in multivariate analysis adjusting for traditional and nontraditional risk factors and antihypertensive and calcitriol treatment. In the longitudinal study, LVMI rose from 60.1 ± 17.9 to 64.2 ± 19.3 g/m^2.7 (P < .001), and again, the number of B alleles was associated with LVMI changes both in crude and in fully adjusted analyses. These cross‐sectional and longitudinal observations coherently support the hypothesis that altered vitamin D signaling is implicated in LVH in ESRD patients. © 2010 American Society for Bone and Mineral Research     

Seasonal variations of hyponatremia in the emergency department: Age-related changes

Study objective

We investigated seasonal prevalence of hyponatremia in the emergency department (ED).