[Predictive value of four score systems on the bleeding risk in atrial fibrillation patients treated with dabigatran].

Objective: To compare the predictive value of HAS-BLED, HEMORR2HAGES, ATRIA and ORBIT scores on the bleeding risk in nonvalvular atrial fibrillation (NVAF) patients treated with dabigatran. Methods: Data of 942 NVAF patients participating a non-interventional prospective study of anticoagulant therapy with dabigatran, which was conducted in 12 centers from February 2015 to December 2017 in China, were analyzed. Complete HAS-BLED HEMORR2HAGES, ATRIA and ORBIT bleeding risk scores data and follow-up data were available in the enrolled patients. The endpoint of the study was bleeding events occurred during a 6 months follow-up. Cox proportional hazards models were constructed to analyze the associations between HAS-BLED, HEMORR2HAGES, ATRIA and ORBIT scores and risk of bleeding, and the area under the curve (AUC) of receiver operating characteristics curves (ROC) of each score was used to set the predictive value for bleeding risk. Results: Among the 942 patients, the mean age was (65.3±11.2) years old, 542 (57.5%) were males. A total of 93 (9.9%) bleeding events occurred during follow up, 89 (9.4%) events were minor bleeding, and 4 (0.4%) events were major bleeding. Patients with a high-risk HAS-BLED score had a 1.87-fold increased risk of bleeding compared with low-risk patients (HR = 2.87, 95% CI:1.26-6.51, P = 0.012). There was no statistically significant difference between low-medium-high-risk grading in other scoring systems and bleeding risk (all P>0.05). The AUC (95%CI) of HAS-BLED, HEMORR2HAGES, ATRIA and ORBIT bleeding risk scores were 0.558 (0.525-0.590), 0.520 (0.487-0.553), 0.513(0.480-0.545), 0.523(0.490-0.555), respectively. The AUC of all bleeding score systems were of ≤ 0.700. Conclusion: Among the NVAF patients taking dabigatran in China, the HAS-BLED bleeding risk score is superior to other 3 bleeding risk score on predicting the bleeding risk in these patients, but its predictive value is still relatively low.

Analysis on the local structures for 3d1 impurities (Ti3+ and V4+ ) in KTiPO4.

Making use of the perturbation formulae for 3d1 ions (Ti3+ and V4+ ) under orthorhombically compressed octahedra, the spin Hamiltonian parameters (g factors: gx , gy , gz and hyperfine structure constants: Ax , Ay , Az ) and local structures of the 3d1 impurity centres C1 , C2 , and C3 in KTiOPO4 crystals are theoretically analyzed in a consistent way. The remarkable local distortions (i.e., the relative axial compression ratios 11.2%, 7.0%, and 5.5% along Z axis and the relative planar bond length variation ratios 15.9%, 7.0%, and 6.0%) are obtained for the [Ti2O6 ]9- cluster on Ti2 site and [VO6 ]8- clusters on Ti1 and Ti2 sites, respectively, in view of the Jahn-Teller effect. The above local orthorhombic distortion parameters in the impurity centres are found to be more significant than the host Ti1 and Ti2 sites in pure KTiOPO4 . The sequences (C1  > C2  > C3 ) of the local orthorhombic distortion parameters ρ and τ are in accordance with those of the axial and perpendicular anisotropies Δg and δg of g factors, respectively.