In 21 patients with ischaemic strokes we have monitored plasma viscosity, total plasma concentration, numeric average molecular weight (Mn), and weight average molecular weight (Mw) of Dextran 40 (dextran) and hydroxyethylstarch 200/0.5 (HES) during 10 days of treatment (days 1-4, 2 X 500 ml; days 5-10, 1 X 500 ml). Plasma concentrations of dextran increased during the first 4 days (8.3 mg X ml-1 on the first day to 18.0 mg X ml-1 on the fifth day), reached an apparent steady state of 17.2 mg X ml-1 during the next 6 days, and declined subsequently with a half-time (t1/2) of 4.03 days. After ten days treatment Mn and Mw were shifted towards higher values. Plasma viscosity increased from 1.26 mPas to 1.69 mPas on Day 10 (p less than 0.01) and was linearly correlated with the total plasma concentration of dextran (p less than 0.001; r = 0.88). Total plasma concentrations of HES averaged 11.7 mg X ml-1 on Day 1 and 12.4 mg X ml-1 on Day 5. The molecular weight distribution did not change during the infusions but decreased in comparison with the administered solution. Plasma viscosity fell from 1.40 mPas to 1.30 mPas at Day 10 (p less than 0.05) and was not related to the concentration of HES. The haemodiluting effect, as indicated by a decrease of the haematocrit, was 22% and 16.8% for dextran and HES respectively. These data suggest several advantages of HES compared with dextran in haemodilution therapy of ischaemic stroke.
Background
Heyde syndrome (HS) is known as the association of severe aortic stenosis (AS) and recurrent gastrointestinal bleeding (GIB) from angiodysplasia. Data on the prevalence of HS and results after TAVI remain scarce.
Methods
2548 consecutive patients who underwent TAVI for the treatment of AS from 2008 to 2017 were evaluated for a history of GIB and the presence of HS. The diagnosis of HS was defined as a clinical triad of severe AS, a history of recurrent GIB, and an endoscopic diagnosis of angiodysplasia. These patients (Heyde) were followed to investigate clinical outcomes, bleeding complications and the recurrence of GIB and were compared to patients with GIB unrelated to HS (Non-Heyde).
Results
A history of GIB prior to TAVI was detected in 190 patients (7.5%). Among them, 47 patients were diagnosed with HS (1.8%). Heyde patients required blood transfusions more frequently compared to Non-Heyde patients during index hospitalization (50.0% vs. 31.9%, p = 0.03). Recurrent GIB was detected in 39.8% of Heyde compared to 21.2% of Non-Heyde patients one year after TAVI (p = 0.03). In patients diagnosed with HS and recurrent GIB after TAVI, the rate of residual ≥ mild paravalvular leakage (PVL) was higher compared to those without recurrent bleeding (73.3% vs. 38.1%, p = 0.05).
Conclusion
A relevant number of patients undergoing TAVI were diagnosed with HS. Recurrent GIB was detected in a significant number of Heyde patients during follow-up. A possible association with residual PVL requires further investigation to improve treatment options and outcomes in patients with HS.
Graphic abstract
Viscoelastic parameters were evaluated in 169 consecutive male patients with clinical signs of coronary heart disease. The patients were classified according to the extent of coronary artery stenosis. Levels of blood viscosity, erythrocyte aggregation, and plasma viscosity were elevated in patients with extensive coronary vessel disease. However, the differences between the several groups were not statistically significant. The increase of hemorheologic parameters was mainly due to high hematocrit, fibrinogen, and cholesterol concentrations. There was a significant correlation between plasma fibrinogen values and plasma viscosity levels. Blood viscosity and erythrocyte aggregation can be described by multiple linear regression as a function of the sum of log hematocrit, fibrinogen, cholesterol, and alpha 2-macroglobulin.
A gas liquid chromatographic assay was developed to measure in plasma and urine concentrations of the new antiarrhythmic drug lorcainide, its dealkylated metabolite and an added internal standard of similar structure. The limit of sensitivity was 10ng/ml plasma. In 5 healthy volunteers and in 6 patients with ventricular premature beats (VPB) the pharmacokinetics were determined after a single intravenous dose of 100mg. In 4 of the patients with VPB, the disposition was also evaluated under steady-state conditions following oral administration of 100mg twice daily. In 4 of the healthy volunteers, the bioavailability of a single 100mg(n = 2) and 150mg (n = 2) oral dose was determined. In an additional crossover experiment, bioavailability of a single oral dose of 100 and 200mg was also measured in 2 patients with VPB. Less than 2% of the intravenous dose could be recovered as unchanged lorcainide in the urine, indicating extensive metabolism. The drug was bound to plasma proteins to the extent of 85.0 +/- 5.0% (mean +/- SD) in healthy subjects and 83.3 +/- 2.9% in patients with VPB. Since the plasma levels declined biexponentially after an intravenous dose, data were analysed according to a 2-compartment open model. The elimination half-life (t1/2beta) of 5.1 +/- 0.6h (healthy subjects) was somewhat longer (p = 0.02) in patients with VPB (7.6 +/- 2.2h), but total plasma or blood clearance were very similar; the latter approaching a normal liver blood flow of 1.5L/min. The apparent distribution volumes Vdbeta (8.6 +/- 2.4L/kg vs 10.7 +/- 4.2L/kg) and Vdss (6.4 +/- 2.4L/kg vs 8.8 +/- 3.4L/kg) showed no statistically significant difference between the healthy subjects and patients. After oral doses, high and saturable first--pass hepatic metabolism seems to exist. The crossover experiments in 4 subjects indicated bioavailability of about 1 to 4.5% after a single 100mg dose, between 7 and 20% after a 150mg dose, and between 35 and 65% after a 200mg dose. In contrast, 3 of 4 patients with VPB on oral maintenance therapy exhibited bioavailability of 100%. This indicates that lorcainide belongs to the group of drugs exhibiting non-linear elimination kinetics.
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