Fibrin monomer complex as a potential thrombosis marker related to venous thromboembolism risk in pregnant women.

BACKGROUND: Pregnancy is a risk factor for venous thromboembolism (VTE) due to increased coagulation factor activity and decreased protein S activity. However, thrombosis markers for predicting VTE in pregnancy remain controversial. This study aimed to investigate the relationship between VTE risk and thrombosis markers in pregnant women and to identify markers related to VTE risk. METHODS: Archived plasma samples from 107 pregnant women were used in this study, and the concentrations of D-dimer, fibrin monomer complex (FMC), plasmin-plasmin inhibitor complex, prothrombin time, activated partial thromboplastin time, and fibrinogen were measured. VTE risk was scored according to the Royal College of Obstetricians and Gynaecologists green-top guidelines and the patients were divided into low- or high-risk groups. RESULTS: The median (range) of risk score for deep vein thrombosis was 2 (0-8), and we defined the high-risk group included those with a score of ≧3. D-dimer and FMC concentrations were significantly higher in the high-risk group than in the low-risk group (D-dimer 4.5 vs 2.6 µg/mL, p = 0.008; FMC 14.6 vs 3.4 µg/mL, p < 0.001). Although D-dimer concentration significantly increased with gestational age (Spearman's correlation coefficient [rs] = 0.317, p < 0.001), FMC concentration did not (rs = -0.081, p = 0.409). The area under the receiver operating characteristic curve values of D-dimer, FMC, and both D-dimer and FMC for the high-risk group were 0.656, 0.713, and 0.738, respectively. CONCLUSIONS: FMC may be a thrombosis marker related to VTE risk in pregnancy and is potentially preferable over D-dimer concentrations.

Regression Analysis to Estimate the Factor VIII Activity of Patients with Hemophilia A Without Inhibitor who Received Emicizumab Therapy.

BACKGROUND: Emicizumab, a bispecific monoclonal antibody for hemophilia A (HA), has strong pharmacodynamic effects in several coagulation assays resulting in dosing difficulties with Factor VIII (FVIII) concentrates during bleeding emergencies. MATERIALS AND METHODS: Single and multiple regression models were studied to estimate FVIII activity using 27 archived plasma samples from three patients with HA without inhibitor under emicizumab treatment. Explanatory variables were FVIII chromogenic assay (CSA), Ad|min1|, Ad|min2|, the number of seconds of APTT, and the FVIII one-stage assay (OSA), which were measured without idiotype antibodies. The response variable was FVIII OSA measured with idiotype antibodies. RESULTS: In the simple linear model, the FVIII CSA regression coefficient was 1.04 and the intercept was -14.55 (r2 = 0.95; p < 0.001). In the multiple regression model, FVIII OSA and FVIII CSA were selected based on the Akaike Information Criterion, with regression coefficients of 1.74 and 1.15, respectively, and an intercept of -92.03 (r2 = 0.96, p < 0.001). CONCLUSIONS: The regression models can estimate the FVIII:C levels in patients with HA receiving emicizumab and would be useful in a bleeding emergency and/or surgery.

Sample Entropy in Electrocardiogram During Atrial Fibrillation.

BACKGROUND: Atrial fibrillation (AF) is an arrhythmia commonly encountered in clinical practice. There is a high risk of thromboembolism in patients with AF. Nonlinear analyses such as electroencephalogram (EEG), electrocardiogram (ECG), and respiratory movement have been used to quantify biological signals, and sample entropy (SampEn) has been employed as a statistical measure to evaluate complex systems. In this study, we examined the values of SampEn in ECG signals for patients with and without AF to measure the regularity and complexity. METHODS: ECG signals of lead II were recorded from 34 subjects without arrhythmia and 15 patients with chronic AF in a supine position. The ECG signals were converted into time-series data and SampEn was calculated. RESULTS: The SampEn values for the group without arrhythmia were 0.252 ± 0.114 [time lag (τ) = 1] and 0.533 ± 0.163 (τ = 5), and those for the chronic AF group were 0.392 ± 0.158 (τ = 1) and 0.759 ± 0.246 (τ = 5). The values of SampEn were significantly higher in the group with chronic AF than in the group without arrhythmia (P < 0.01 for τ = 1, P < 0.004 for τ = 5). The constructed three-dimensional vectors were plotted in time-delayed three-dimensional space. We used time lags of τ = 5 and τ = 1. The shape of the loops of the three-dimensional space was better for τ = 5. CONCLUSION: The values of SampEn from ECG for chronic AF patients were higher than for subjects without arrhythmia, suggesting greater complexity for the time-series from chronic AF patients. SampEn is considered a new index for evaluating complex systems in ECG.

A Modified Method for Examining the Walking Pattern and Pace of COPD Patients in a 6-min Walk Test Before and After the Inhalation of Procaterol.

Objective The 6-min walk test (6MWT) is a simple test that is used to examine the exercise tolerance and outcomes in patients with chronic obstructive pulmonary disease (COPD). Although the 6MWT is useful for assessing exercise tolerance, it is difficult to evaluate time-dependent parameters such as the walking pattern. A modified 6MWT has been devised to assess the walking pattern by calculating the number of steps per second (NSPS). This study was performed to investigate walking pattern of COPD patients in the modified 6MWT before and after a single inhalation of the short-acting ß2-agonist procaterol. Methods Nine male COPD patients participated in this study. The 6MWT was performed before and after the inhalation of procaterol hydrochloride. A digital video recording of the 6MWT was made. After the 6MWT, the number of steps walked by the subject in each 5-s period was counted manually with a hand counter while viewing the walking test on the video monitor. Results After the inhalation of procaterol, the 6-min walking distance increased significantly in comparison to baseline (p<0.01). The mean NSPS was also significantly increased after the inhalation of procaterol in comparison to baseline (p<0.01). The walking pattern was displayed on a graph of time versus NSPS, and the walking pace was shown by a graph of time versus cumulative steps. Conclusion The analysis of the COPD patients' walking test performance and their walking pattern and pace in the 6MWT may help to evaluate the effects of drug treatment.

Approximate Entropy of Respiratory Movements in Human Newborns during Different Sleep States.

Previous studies have reported that the respiratory cycle of healthy newborns is more irregular during active sleep. This study aimed to apply non-linear analysis to examine the irregularity of respiratory movement in newborns at different sleep states. The respiratory movement signals from an abdominal band during quiet and active sleep were analyzed using approximate entropy (ApEn). The breathing interval of active sleep was significantly shorter than that of quiet sleep [1.30 (0.17) s vs. 1.58 (0.11) s; (P < 0.03)]. The ApEn of respiratory movements during active sleep were significantly larger than that during quiet sleep [0.785 (0.135) s vs. 0.678 (0.083) s; (P < 0.05)]. We found that the ApEn of respiratory movement in healthy newborns could detect irregularities in respiration during sleep.

[Approximate entropy of electrocardiogram signals in atrial fibrillation].

Atrial fibrillation (Af) is a common arrhythmia and disorder of the rhythm of electrical activation of the cardiac atria. There is a high risk of thromboembolism in patients with Af. Therefore, it is an indication for anticoagulant therapy. The approximate entropy (ApEn) of electrocardiogram (ECG) signals was calculated in 29 subjects without arrhythmia and 12 patients with chronic Af. The mean ApEn in the group without arrhythmia was 0.347 +/- 0.119, and that of the chronic Af group was 0.556 +/- 0.169. ApEn was significantly higher in the chronic Af group than in the no arrhythmia group (p < 0.002). The average ApEn was significantly higher in the group not administered anti-arrhythmic drugs (0.687 +/- 0.033) than that in the group administered anti-arrhythmic drugs (0.516 +/- 0.209) (p < 0.05). We found that ApEn was effective in evaluating the nonlinear property and ApEn of ECG signals, enabling assessment of the randomness of chronic Af.