Risk of venous thromboembolism in Chinese pregnant women: Hong Kong venous thromboembolism study

BACKGROUND: Previous Caucasian studies have described venous thromboembolism in pregnancy; however, little is known about its incidence during pregnancy and early postpartum period in the Chinese population. We investigated the risk of venous thromboembolism in a “real-world” cohort of pregnant Chinese women with no prior history of venous thromboembolism. METHODS: In this observational study, 15,325 pregnancies were identified in 14,162 Chinese women at Queen Mary Hospital, Hong Kong between January 2004 and September 2016. Demographic data, obstetric information, and laboratory and imaging data were retrieved and reviewed. RESULTS: The mean age at pregnancy was 32.4±5.3 years, and the median age was 33 years (interquartile range, 29–36 yr). Pre-existing or newly diagnosed diabetes mellitus was present in 627 women (4.1%); 359 (0.7%) women had pre-existing or newly detected hypertension. There was a small number of women with pre-existing heart disease and/or rheumatic conditions. Most deliveries (86.0%) were normal vaginal; the remaining were Cesarean section 2,146 (14.0%). The incidence of venous thromboembolism was 0.4 per 1,000 pregnancies, of which 83.3% were deep vein thrombosis and 16.7% were pulmonary embolism. In contrast to previous studies, 66.7% of venous thrombosis occurred in the first trimester. CONCLUSION: Chinese women had a substantially lower risk of venous thromboembolism during pregnancy and the postpartum period compared to that of Caucasians. The occurrence of pregnancy-related venous thromboembolism was largely confined to the early pregnancy period, probably related to the adoption of thromboprophylaxis, a lower rate of Cesarean section, and early mobilization.

The evaluation of left ventricular strain using speckle tracking echocardiography in normal young adults：comparison of three-dimensional and two-dimensional approaches / 中华医学超声杂志（电子版）

Objective To investigate the value of three-dimensional speckle tracking imaging (3D-STI) in assessment of left ventricular (LV) strains. Methods Thirty healthy young adults examined by two-dimensional speckle tracking imaging (2D-STI) and 3D-STI. And the results of LV measurements were compared, which included mean peak systolic longitudinal strains, radial strains and circumferential strains. Also, the time consumption of these two methods was compared. Results The time needed for 3D-STI in acquisition and analysis of the images were (309.3±23.4)s, (305.5±11.2)s, while the time for 2D-STI were (490.6±14.4)s, (1261.4±39.9)s. The differences were signiifcant(t=-21.81, 69.94, both P<0.01). The global mean peak systolic radial strains was (48.59±7.68)%by 3D-STI and (33.25±7.27)%by 2D-STI. The difference was signiifcant(t=9.16, P<0.01). The global mean peak systolic longitudinal and circumferential strains were (-17.66±3.14)%, (-17.13±2.29)% by 3D-STI and (-21.35±2.46)%, (-21.97±3.84)% by 2D-STI. The differences were signiifcant(t=5.33, 5.99, both P < 0.01). The 3D-STI strains were different at different levels of LV. The longitudinal, circumferential and radial 3D-STI strains were largest at middle levels. However, 2D-STI strains didn′ t show such trend. Peak strains measured by 3D-STI and 2D-STI showed high inter-observer and intra-observer agreement in Bland-Altman chart. Conclusion 3D-STI is a novel, convenient and reproducible method to evaluate the strains of LV.

Assessment of carotid plaque rotation angle using ultrasonic imaging / 中国医学科学院学报

<p><b>OBJECTIVE</b>To demonstrate the abnormal intima rotation pattern of the carotid atherosclerosis plaque using velocity vector imaging, and to develop a new method for the clinical mechanical state assessment of the plaque intima.</p><p><b>METHODS</b>The rotation movement and rotation angle on the serial dynamic ultrasonic short-axis gray scale views of 48 isolated atherosclerosis plaques (i. e., upstream, midstream, and downstream) and nearby reference segments of carotid artery in 46 patients were derived and analyzed using a dedicated velocity vector imaging workstation. The incidence of intima rotation movement and the rotation angle at different sections of the plaque and nearby reference segments before and after the standard grip stress test during systole and diastole respectively were counted and measured.</p><p><b>RESULTS</b>Before and after the stress test, the intima rotation movement occurred at the majority of the short-axis sections of the plaque and the nearby reference segments during cardiac cycle. Before the stress test, the incidence of intima rotation movement at the upstream section of the plaque during systole was significantly higher than that of reference segment (P = 0.036) The reversal direction of the intima rotation at those sections and reference segment during systole and diastole was demonstrated. After the stress test, the incidence of intima rotation movement at the midstream section of the plaque during diastole was significantly lower than that of reference segment (P = 0.031). The incidence of the intima rotation movement changed at the sections of upstream, midstream, and downstream of the plaque before and after the stress test also were explored (i. e., increased in systole and decreased in diastole) except the reference segment intima.</p><p><b>CONCLUSIONS</b>The intima rotation movement occurs at the majority of the isolated plaque and nearby reference segment, and the incidences of the intima rotation movement at the plaque is different from that of the reference segment during systole and diastole respectively. The abnormal pattern of intima rotation movement may be used to indicate the unstable mechanical state of the isolated plaque intima.</p>