Adele Romano

Prevalence of renal failure and use of antithrombotic prophylaxis among medical inpatients at increased risk of venous thromboembolic events

BACKGROUND Evidence-based guidelines recommend the use of antithrombotic prophylaxis in medical patients at risk of venous thromboembolism (VTE). Low molecular weight heparins (LMWHs) are usually preferred to unfractionated heparin. However, when prophylactic doses of LMWH are administered, patients with renal failure (RF) are exposed to the risk of excessive accumulation, and thus to an increased risk of bleeding. We aimed to assess the prevalence of RF among medical inpatients at increased risk of VTE and the use and dosage of antithrombotic prophylaxis in these patients. METHODS In a cross sectional study carried out at three different hospitals, information on all medical inpatients was collected. Patients were defined at increased risk of VTE according to the American College of Chest Physicians guidelines. Data on the proportion of patients with renal RF, on the use and dosage of antithrombotic prophylaxis, and on the presence of contraindications to antithrombotic therapy were ascertained. RESULTS 439 hospital charts were examined; 158 patients (36.0%) were defined at increased risk of VTE and had no contraindications to antithrombotic treatment. Thromboprophylaxis was prescribed to 61.4% of these patients. Eighty (50.7%) of them also had moderate or severe RF. There was no difference in the rate of prescription nor in the doses of antithrombotic prophylaxis between patients with and without RF (p=0.81 and p=0.94, respectively). CONCLUSIONS RF is frequently present in medical patients at risk of VTE. A considerable proportion of these patients may not receive the optimal type or dose of antithrombotic prophylaxis.

Membrane Fluidity, Membrane Lipid Pattern, and Cytosolic Ca2+ Content in Platelets from a Group of Type II Diabetic Patients with Macrovascular Complications

OBJECTIVE To evaluate platelet membrane fluidity and some platelet metabolic parameters in type II diabetic patients with macrovascular complications. RESEARCH DESIGN AND METHODS In a group of 21 type II diabetic patients with macrovascular complications, we evaluated platelet membrane fluidity [marking intact resting platelets with the fluorescent probe 1,4-(trimethylamino)-phenyl-4-phenylhexatriene (TMA-DPH)], platelet membrane lipid pattern (cholesterol :phospholipid [C:PL] ratio and individual phospholipids), and platelet cytosolic Ca2+ content (marking intact resting platelets with the fluorescent probe Fura 2AM). RESULTS Platelet membrane fluidity is decreased in type II diabetic patients with macrovascular complications compared with normal subjects (P < 0.001). Platelet membrane C:PL ratio and cytosolic Ca2+ content do not discriminate normal subjects from diabetic patients, and for individual phospholipids, only phosphatidylethanol-amine is decreased in diabetic patients compared with control subjects (P = 0.051). In normal subjects, the polarization degree of TMA-DPH is related to phosphatidylserine (P < 0.05) and phosphatidylcholine (P < 0.05), and in diabetic patients the polarization degree of TMA-DPH is related to C:PL ratio (P < 0.05) and sphyngomyelin (P < 0.05). CONCLUSIONS In type II diabetic patients with macrovascular complications, we observed an abnormality of platelet membrane fluidity, which may contribute to platelet functional alteration present in this clinical condition.

Erythrocyte deformability and nitric oxide metabolites in athletes before and after a cardiopulmonary test

Objective:To evaluate erythrocyte deformability, nitric oxide metabolites, and their modifications induced by exercise in athletes who practised different sports. Design:This evaluation was effected before and after cardiopulmonary test, using a cycloergometer. Setting:The study was performed in the Department of Internal Medicine, Cardiovascular and Renal Diseases of the University of Palermo. Participants:We enrolled 62 male athletes who practised endurance (n = 23), mixed (n = 20), and power (n = 19) sports and 20 sedentary male subjects as controls. Assessment of Risk Factors:No subject had diabetes or hypertension or dyslipidemia. Five control subjects and 14 athletes were smokers. Main Outcome Measures:Erythrocyte deformability was examined as elongation index (EI) using a diffractometer. The nitric oxide metabolites (nitrite + nitrate = NOx) were evaluated employing the Griess reagent. Results:In the whole group, an increase in EI and NOx was present. Subdividing the whole group into 3 subgroups, we noted an increase in EI and NOx only in endurance and mixed athletes. The EI before and after the cardiopulmonary test significantly decreased in the whole group and in power athletes but not in endurance and mixed athletes. Before and after the test, NOx did not significantly change in the whole group and in the 3 subgroups. Conclusions:In athletes who practised endurance and mixed sports, we observed an increase of NOx level and an increase of erythrocyte deformability. The latter did not change after an exercise test in the same subgroups, whereas it decreased in power athletes.

Relationship between elastase and total antioxidant status in young subjects with recent myocardial infarction.

In a group of young subjects with acute myocardial infarction (AMI) (68 men and 7 women; mean age 39.6+/-5.7 years) we examined the plasma concentration of elastase, the thiobarbituric acid-reactive substances (TBARS) and the total antioxidant status (TAS) at the initial stage of AMI. In this group we found an increase of elastase (p<0.001) and TBARS (p<0.001) and a decrease of TAS (p<0.001). A statistical correlation was observed in the whole group of AMI patients between plasma elastase and TAS (p<0.01) and this correlation was more statistically significant in patients with more risk factors and not in those with more involved vessels.

Vascular atherosclerotic disease: evaluation of the whole-blood f ilterability and red cell membrane microrheological pattern after intravenous administration of a single dose of pentoxifylline

A study was carried out in 10 patients with vascular atherosclerotic disease to investigate the effects of a single dose of 300 mg pentoxifylline, given by intravenous infusion over 30 minutes, on various macrorheological and microrheological parameters. Measurements were made at baseline, at the end of the intravenous infusion and again 30 minutes later, of whole-blood filterability, erythrocyte membrane fluidity (using pyrene as probe) and transverse fluidity gradient (using fluorescent fatty acids as probes). The results showed that there was a significant variation in whole-blood filterability and the red cell membrane fluidity gradient after pentoxifylline. No difference, however, was noted for the membrane fluidity. These data suggest, therefore, that pentoxifylline plays a role in affecting the red cell membrane microrheological pattern.

Hemorheologic profile of hyperlipidemic patients treated with gemfibrozil

Abstract We measured the plasma lipid levels and the macrorheologic (whole-blood, plasma, and serum viscosity levels; fibrinogen; hematocrit; mean erythrocyte aggregation; and whole-blood filterability) and microrheologic (erythrocyte membrane fluidity and red cell membrane protein lateral mobility) determinants in a group of 19 hyperlipidemic patients (Fredricksons classification phenotype IIa, 12 patients; phenotype IV, 4; phenotype IIb, 3) at baseline and after 45 and 90 days of treatment with gemfibrozil (900 mg orally once a day). At baseline we noted statistically significant increases in plasma viscosity level, fibrinogen, and mean erythrocyte aggregation, as well as a statistically significant decrease in whole-blood filterability, erythrocyte membrane fluidity, and red cell membrane protein lateral mobility in hyperlipidemic patients compared with healthy subjects. The gemfibrozil treatment provided a statistically significant decrease of the plasma lipid levels, but had little effect on the hemorheologic profile.