Thoralf Stange

Peri-interventional management of novel oral anticoagulants in daily care: results from the prospective Dresden NOAC registry

AIMS Patients receiving novel oral anticoagulants (NOACs) frequently undergo interventional procedures. Short half-lives and rapid onset of action allow for short periods of NOAC interruption without heparin bridging. However, outcome data for this approach are lacking. We evaluated the peri-interventional NOAC management in unselected patients from daily care. METHODS AND RESULTS Effectiveness and safety data were collected from an ongoing, prospective, non-interventional registry of >2100 NOAC patients. Outcome events were adjudicated using standard event definitions. Of 2179 registered patients, 595 (27.3%) underwent 863 procedures (15.6% minimal, 74.3% minor, and 10.1% major procedures). Until Day 30 ± 5 post-procedure, major cardiovascular events occurred in 1.0% of patients [95% confidence interval (95% CI) 0.5-2.0] and major bleeding complications in 1.2% (95% CI 0.6-2.1). Cardiovascular and major bleeding complications were highest after major procedures (4.6 and 8.0%, respectively). Heparin bridging did not reduce cardiovascular events, but led to significantly higher rates of major bleeding complications (2.7%; 95% CI 1.1-5.5) compared with no bridging (0.5%; 0.1-1.4; P = 0.010). Multivariate analysis demonstrated diabetes [odds ratio (OR) 13.2] and major procedures (OR 7.3) as independent risk factors for cardiovascular events. Major procedures (OR 16.8) were an independent risk factor for major bleeding complications. However, if major and non-major procedures were separately assessed, heparin bridging was not an independent risk factor for major bleeding. CONCLUSION Continuation or short-term interruption of NOAC is safe strategies for most invasive procedures. Patients at cardiovascular risk undergoing major procedures may benefit from heparin bridging, but bleeding risks need to be considered.

Safety of switching from vitamin K antagonists to dabigatran or rivaroxaban in daily care – results from the Dresden NOAC registry

AIM Vitamin-K antagonists (VKA) and non-vitamin-K dependent oral anticoagulants (NOAC) have been approved for anticoagulation in venous thromboembolism (VTE) and atrial fibrillation and patients previously treated with VKA are switched to NOAC therapy. Safety data for this switching are urgently needed. METHODS Using data from a large regional prospective registry of daily care NOAC patients, we evaluated the safety of switching anticoagulation from VKA to dabigatran or rivaroxaban. Switching procedures and cardiovascular and bleeding events occurring within 30 days after switching were centrally adjudicated. RESULTS Between 1 October 2011 and 18 June 2013, 2231 patients were enrolled. Of these, 716 patients were switched from VKA to NOAC. Only 410 of the 546 evaluable patients (75.1%) had a recorded INR measurement within the 10 days preceding or following the end of VKA treatment (mean INR 2.4). As of day 30, major bleeding complications were rare (0.3%; 95% CI 0.0, 1.0) with an overall bleeding rate of 12.2% (95% CI 9.8, 14.8). Major cardiovascular events occurred in 0.8% (95% CI 0.3, 1.8). There was no significant difference in outcome event rates between the subgroups of patients with or without INR testing. CONCLUSION In daily care, only 75% of VKA patients have an INR measurement documented before NOAC are started. On average, NOAC are started within 2 to 5 days after the last intake of VKA. However, at 30 days follow-up cardiovascular events or major bleedings were rare both in patients with and without INR testing. However, switching procedures need to be further evaluated in larger cohorts of patients.

Efficacy and safety of thromboprophylaxis with low-molecular-weight heparin or rivaroxaban in hip and knee replacement surgery

Prospective trials have shown that rivaroxaban thromboprophylaxis is superior over low-molecular-weight heparin (LMWH) in patients undergoing hip and knee replacement surgery. However, patients treated under trial conditions are different from unselected routine patients, which may affect efficacy and safety of thromboprophylaxis. The objective was to evaluate the efficacy and safety of rivaroxaban or LMWH thromboprophylaxis in unselected patients undergoing hip and knee replacement surgery in daily care. In a monocentric, retrospective cohort study in 5,061 consecutive patients undergoing hip and knee replacement surgery a comparison of LMWH (hospital standard in 2006-2007) and rivaroxaban (since 2009) was made with regard to rates of symptomatic VTE, bleeding and surgical complications and length of hospital stay. Rates of symptomatic VTE were 4.1 % (LMWH) and 2.1 % (rivaroxaban; p=0.005) with rates for distal DVT 2.5 vs. 1.1 % (p<0.001). Rates of major VTE were numerically higher with LMWH (1.7 vs. 1.1%, not statistically significant). Rates of major bleeding (overt bleeding leading to surgical revision or death, occurring in a critical site, or transfusion of at least two units of packed red blood cells) were statistically lower with rivaroxaban (2.9 vs. 7.0%; p<0.001). Rivaroxaban patients had fewer surgical complications (1.1 vs. 3.7%; p<0.001) and a shorter length of hospitalisation (8.3 days; 95% CI 8.1- 8.5 vs. 11.1 days; 10.7- 11.5; p< 0.001). We conclude that rivaroxaban thromboprophylaxis is more effective than LMWH in unselected patients undergoing hip and knee replacement surgery in daily care and that switching from LMWH to rivaroxaban could be beneficial. Prospective comparisons are warranted to confirm our findings.

Trends in Incidence Rates during 1999-2008 and Prevalence in 2008 of Childhood Type 1 Diabetes Mellitus in GERMANY – Model-Based National Estimates

Aims To estimate the national incidence rate and trend of type 1 diabetes (T1DM) in Germany from 1999 to 2008 and the national prevalence in 2008 in the age group 0–14 years. Methods Data were taken from a nationwide registry for incident cases of T1DM in the ages 0–4 years and 3 regional registries (North-Rhine-Westphalia, Baden-Wuerttemberg and Saxony) for incident cases of T1DM in the ages 0–14 years covering 41% of the child population in Germany. The degree of ascertainment was ≥ 97% in all registries. Incident and prevalent cases were grouped by region, sex, age (0–4, 5–9, 10–14 years), and, for incident data, additionally by two 5-year periods (1999–2003, 2004–2008). Poisson regression models were fitted to the data to derive national estimates of incidence rate trends and prevalence in the age groups 5–9, 10–14 and 0–14 years. We used direct age-standardization. Results The estimated national incidence rate in 0-14-year-olds increased significantly by 18.1% (95%CI: 11.6–25.0%, p<0.001) from 1999–2003 to 2004–2008, independent of sex, corresponding to an average annual increase of 3.4% (95%-CI: 2.2–4.6%). The overall incidence rate was estimated at 22.9 per 100,000 person-years and we identified a within-country west-east-gradient previously unknown. The national prevalence in the ages 0–14 years on 31/12/2008 was estimated to be 148.1 per 100,000 persons. Conclusions The national incidence rate of childhood T1DM in Germany is higher than in many other countries around the world. Importantly, the estimated trend of the incidence rate confirms the international data of a global increase of T1DM incidences.

Coagulation activation after discontinuation of VTE treatment with different oral anticoagulants and impact on 12-month clinical outcomes

Increasing D-dimer (DD) levels after discontinuation of vitamin K antagonist (VKA) therapy indicate an increased risk of recurrence of venous thromboembolism (VTE). However, after discontinuation of direct-acting non-VKA oral anticoagulants (DOACs or NOACs) the extent of coagulation activation and its clinical impact is unknown. Blood samples were collected from consenting patients with proximal VTE at the end of anticoagulation treatment with apixaban (n=37), dabigatran (n=17), rivaroxaban (n=9) or VKA (n=184) and 4weeks later. DD, prothrombin fragments F1+2 (F1+2) and thrombin-antithrombin complexes (TAT) were measured. All patients underwent follow-up at 12months to establish recurrent VTE or death from any cause. Irrespective of the treatment, DD and F1+2 but not TAT demonstrated a similar increase between baseline and week 4. At 12months, 18 patients (7.3%) had recurrent VTE and two (0.8%) had died. For all patients and subgroups of VKA and DOAC, positive likelihood ratios were numerically higher for baseline values but only TAT values at 4weeks were found to be related to a small increase of outcome event likelihood (2.6; 95%CI 1.23-5.50), which was driven by VKA patients (3.1; 95%CI 1.32-7.30) and not by DOAC patients (2.27; 95%CI 0.52-9.95). For all parameters, negative likelihood ratios were not predictive. In logistic regression analysis, only ΔTAT (optimal cut-off >178% from baseline demonstrated a significant risk increase for VTE/death (odds ratio 3.76; 95% confidence interval 1.46-9.68; p=0.006). In conclusion, the concept of testing coagulation activation parameters may also be transferred to VTE patients at the end of DOAC therapy. For patients with an increase of TAT levels within 4weeks after treatment discontinuation (>178% from baseline) is associated with an increased risk for VTE recurrence or death at 12months.