Safety and effectiveness of tinzaparin sodium in the management of recurrent pregnancy loss.

PURPOSE: To assess the safety and efficacy of tinzaparin sodium for the management of recurrent pregnancy loss. METHODS: The study included 62 women with a history of recurrent pregnancy loss and at least one factor of thrombophilic disorder. Of these, 31 received 50 IU/kg of tinzaparin sodium daily (Group A), and 33 received 100 mg of aspirin daily (Group B). RESULTS: Group A subjects (receiving tinzaparin sodium) had six new abortions, whereas Group B subjects (receiving aspirin) had 11 (significant difference). Cases of intrauterine growth restriction (none in Group A and 2 in Group B), placental abruption (one in Group A and 4 in Group B), and preeclampsia (one in Group A and 3 in Group B) were comparable between the two groups. Finally coagulation disorders (none in Group A and 6 in Group B) were significantly fewer in Group A. CONCLUSION: A 50 IU/kg daily dose of tinzaparin sodium seems to be effective for the management of recurrent abortion and has high standards of safety.

Thrombogenicity of radiofrequency lesions: results with serial D-dimer determinations.

OBJECTIVES: By measuring plasma levels of D-dimer, a product of fibrin degradation, we sought to investigate whether the application of radiofrequency (RF) energy might activate endogenous thrombotic mechanisms. BACKGROUND: Quantitative determination of D-dimer, a bio-chemical marker of thrombus formation and reactive fibrinolysis, helps to diagnose activation of the coagulation system. It remains controversial whether endocardial lesions produced during RF catheter ablation of arrhythmogenic foci have a thrombogenic effect, and the issue of the need for antithrombotic therapy after RF ablation is still unresolved. METHODS: We made serial determinations of plasma D-dimer levels by enzyme immunoassay before insertion of catheters, after completion of electrophysiologic study (EPS) but before RF ablation, immediately after RF ablation and before discharge (at 48 h) from the hospital in 37 patients undergoing RF ablation (22 men, 15 women; mean [+/-SD] age 37 +/- 18 years, range 12 to 74; 16 +/- 16 lesions produced) of accessory (n = 17) or slow (n = 12) pathways, atrial (n = 4) or ventricular foci (n = 3) or the atrioventricular node (n = 1). D-dimer levels were also measured in 26 age-matched control subjects undergoing EPS only. RESULTS: In the RF ablation group, the mean D-dimer levels increased from a baseline value of 29 +/- 28 to 62 +/- 56 micrograms/liter after EPS (p < 0.0001). However, after RF ablation, D-dimer levels increased to much higher levels (188 +/- 138 micrograms/liter, p < 0.0001). There was no correlation of D-dimer levels with the number of RF lesions produced or the duration of the procedure. At 48 h after the procedure, D-dimer levels decreased (75 +/- 67 micrograms/liter) but still remained significantly elevated compared with baseline values (p = 0.0001). Three were no significant differences in baseline (25 +/- 21 micrograms/liter) and post-EPS (51 +/- 50 micrograms/liter) measurements between control subjects and patients. During RF ablation, intravenous heparin was given to nine patients who still demonstrated high plasma D-dimer levels after RF ablation. CONCLUSIONS: As reflected by elevated plasma D-dimer levels, RF ablation has a thrombogenic effect that persists through 48 h after the procedure. This effect needs to be taken into account when considering antithrombotic therapy in patients undergoing RF ablation.

Pretreatment with aspirin and ticlopidine confers lower thrombogenic potential of radiofrequency catheter ablation.

In the present study we pretreated 31 patients undergoing radiofrequency catheter ablation (RFA) with combined aspirin and ticlopidine for 3 days before the procedure, whereas 37 patients did not receive pretreatment. D-dimer levels reflecting the thrombogenic potential of RFA were significantly lower in the pretreated group at each stage before, during, and after the procedure, whereas there were no significant differences between the 2 groups in the number of RFA lesions or duration of the procedure.

ISO/IEC 17025 Sysmex R-500 hematology reticulocyte analyzer validation.

The Sysmex R-500 (R-500) Hematology Analyzer is a bench-top system appropriate for the analysis of limited batches of blood samples. The R-500 provides percentage proportional (RET%), absolute reticulocyte (RET#), and absolute red blood cell (RBC#) counts. The system was validated at the Doping Control Laboratory of Athens, according to the International Committee for Standardization in Hematology, International Standards Organization (ISO/IEC) 17025, and World Antidoping Agency (WADA) specifications. The instrument calibration was performed according to the manufacturer and validation parameters comprised linearity, precision, uncertainty (intermediate and long-term precision), comparability, effect of drift, carryover, stability, and accuracy. The linearity and the comparability studies for RET#, RET%, and RBC# were expressed in regression factors (R2) and coefficients of correlation [r(x, y)], respectively. For the precision studies, the coefficients of variation for RET#, RET%, and RBC# were 9.49%, 9.83%, and <1.5%, respectively. For the intermediate precision studies, the coefficients of variation for RET#, RET%, and RBC# were 3.1%, 3.6%, and 0.6%, respectively. Carryover was found to be negligible. Sample stability was demonstrated at both room temperature and at 4 degrees C over a 24-hour period. Comparability studies for the R-500 were performed using a Sysmex SE-9500. The total evaluation led to the conclusion that the R-500 is an accurate and precise analyzer and because of to its relatively limited size, it can be considered a portable instrument, capable to be used in sports competition and training sites, where doping control and health tests are conducted. The analytical methodology of RET% measurement by the R-500 has been incorporated into the Doping Control Laboratory of Athens' Scope of Accreditation according to the ISO/IEC 17025 and WADA specifications.

Evidence of low-grade intravascular coagulation in patients with transvenous pacemakers.

Serum fibrin and fibrinogen degradation products (FDP) were measured in 4 groups of patients. In Group A (30 patients) FDP levels were measured before and 48-60 hours after pacemaker and transvenous electrode placement. They remained negative (less than 10 micrograms/ml) in 14, rose to greater than 10 micrograms/ml less than 40 micrograms/ml in 12, and greater than 40 micrograms/ml in 4. In 12 Group B patients undergoing the same procedure, FDP levels remained negative in 8, and rose in 4 after 24 hours and after 7 days. In 12 Group C patients studied at initial electrode and battery implantation and 3-6 months later, there were the same results in short- and long-term FDP measurements (8 negative and 4 elevated). Finally, in 14 patients with negative FDP levels who underwent battery replacement only, 3.1 to 5.2 years after their initial operation (Group D), no increase of FDP titer was seen postoperatively. Our results suggest that elevated FDP levels suggest subclinical intravenous or intracardiac thrombosis in patients with transvenous pacemakers.

Acute aortic regurgitation caused by non-bacterial thrombotic endocarditis.

A case of non-bacterial thrombotic endocarditis, which caused acute aortic regurgitation in a middle-aged, otherwise healthy woman, is presented. The diagnosis was confirmed with echocardiography and documented by a histopathological study of the excised aortic valve after operation for valve replacement.