The effect of COVID-19 vaccination on anticoagulation stability in adolescents and young adults using vitamin K antagonists

INTRODUCTION

The European Medicine Agency has authorized COVID-19 vaccination in adolescents and young adults (AYAs) from 12 years onwards. In elderly vitamin K antagonist (VKA) users, COVID-19 vaccination has been associated with an increased risk of supra- and subtherapeutic INRs. Whether this association is also observed in AYAs using VKA is unknown. Our aim was to describe the stability of anticoagulation after COVID-19 vaccination in AYA VKA users.

MATERIALS AND METHODS

A case-crossover study was performed in a cohort of AYAs (12-30 years) using VKAs. The most recent INR results before vaccination, the reference period, were compared with the most recent INR after the first and, if applicable, second vaccination. Several sensitivity analyses were performed in which we restricted our analysis to stable patients and patients without interacting events.

RESULTS

101 AYAs were included, with a median age [IQR] of 25 [7] years, of whom 51.5 % were male and 68.3 % used acenocoumarol. We observed a decrease of 20.8 % in INRs within range after the first vaccination, due to an increase of 16.8 % in supratherapeutic INRs. These results were verified in our sensitivity analyses. No differences were observed after the second vaccination compared to before and after the first vaccination. Complications after vaccination occurred less often than before vaccination (9.0 vs 3.0 bleedings) and were non-severe.

CONCLUSIONS

the stability of anticoagulation after COVID-19 vaccination was decreased in AYA VKA users. However, the decrease might not be clinically relevant as no increase of complications nor significant dose adjustments were observed.

Comparison of phenprocoumon with direct oral anticoagulants in catheter ablation of atrial fibrillation

Aims

In patients undergoing catheter ablation for atrial fibrillation (AF), direct oral anticoagulants (DOACs) are as effective and safe as the vitamin K antagonist (VKA) warfarin. Phenprocoumon has a different pharmacokinetic profile compared with warfarin and is the most used VKA in Germany. The aim of the study was to compare DOAC with phenprocoumon.

Methods and results

In this retrospective single-centre cohort study, 1735 patients who underwent 2219 consecutive catheter ablations for AF between January 2011 and May 2017 were included. All patients were in-hospital for at least 48 h after catheter ablation. The primary outcome was defined as peri-procedural thrombo-embolic events. The secondary outcome was any bleeding according to the International Society on Thrombosis and Haemostasis (ISTH). The mean age of the patients was 63.3 years. Phenprocoumon was prescribed in 929 (42%) of the cases, and in 697 (31%) dabigatran, 399 (18%) rivaroxaban, and 194 (9%) apixaban. During hospitalization, 37 (1.6%) thrombo-embolic events occurred, including 23 transient ischaemic attacks (TIAs). Compared with the use of phenoprocoumon, the use of DOAC was significantly associated with a lower thrombo-embolic risk [16 (1.2%) vs. 21 (2.2%), odds ratio (OR)], 0.5 [95% confidence interval (CI) 0.2-0.9], P = 0.04. No statistically significant association with bleeding risk was observed [phenprocomoun: 122 (13%); DOAC: 163 (12.6%); OR 0.9 (95% CI 0.7-1.2); P = 0.70]. Interruption of oral anticoagulation (OAC) was associated with an increased risk for thrombo-embolic complications [OR 2.2 (1.1-4.3); P = 0.031], and bleeding [OR 2.5 (95% CI 1.8-3.2), P = 0.001].

Conclusion

In patients undergoing catheter ablation for AF, the use of DOAC was associated with a reduced risk of thrombo-embolic events compared with phenprocoumon. Non-interrupted oral anticoagulation (OAC) therapy was associated with a reduced risk of peri-procedural thrombo-embolic and any bleeding complications.

GARFIELD-AF: risk profiles, treatment patterns and 2-year outcomes in patients with atrial fibrillation in Germany, Austria and Switzerland (DACH) compared to 32 countries in other regions worldwide

BACKGROUND

The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is a worldwide non-interventional study of stroke prevention in patients with non-valvular AF.

METHODS AND RESULTS

52,080 patients with newly diagnosed AF were prospectively enrolled from 2010 to 2016. 4121 (7.9%) of these patients were recruited in DACH [Germany (n = 3567), Austria (n = 465) and Switzerland (n = 89) combined], and 47,959 patients were from 32 countries in other regions worldwide (ORW). Hypertension was most prevalent in DACH and ORW (85.3% and 75.6%, respectively). Diabetes, hypercholesterolaemia, carotid occlusive disease and vascular disease were more prevalent in DACH patients vs ORW (27.6%, 49.4%, 5.8% and 29.0% vs 21.7%, 40.9%, 2.8% and 24.5%). The use of non-vitamin K antagonist oral anticoagulants (NOACs) increased more in DACH over time. Management of vitamin K antagonists was suboptimal in DACH and ORW (time in therapeutic range of INR ≥ 65% in 44.6% and 44.4% of patients or ≥ 70% in 36.9% and 36.0% of patients, respectively). Adjusted rates of cardiovascular mortality and MI/ACS were higher in DACH while non-haemorrhagic stroke/systemic embolism was lower after 2-year follow-up.

CONCLUSIONS

Similarities and dissimilarities in AF management and clinical outcomes are seen in DACH and ORW. The increased use of NOAC was associated with a mismatch of risk-adapted anticoagulation (over-and-undertreatment) in DACH. Suboptimal control of INR requires educational activities in both regional groups. Higher rates of cardiovascular death in DACH may reflect the higher risk profile of these patients and lower rates of non-haemorrhagic stroke could be associated with increased NOAC use.

Vitamin-K-antagonist phenprocoumon versus low-dose direct oral anticoagulants (DOACs) in patients with atrial fibrillation: a real-world analysis of German claims data

Background

For stroke prevention in patients with atrial fibrillation (AF), direct oral anticoagulants (DOACs) have been increasingly prescribed instead of vitamin-K-antagonists (VKA). For some patients a lower dosage of DOACs (ld-DOACs) is recommended. Ld-DOAC prescribing seems to be common, although previous studies did not show clear superiority of ld-DOACs over warfarin. In Germany, phenprocoumon is used almost exclusively as VKA. Randomized controlled trials comparing DOACs and phenprocoumon in the general population of patients with AF do not exist. Therefore, we aimed to compare ld-DOACs and phenprocoumon in a real-world setting in Germany.

Methods

In a retrospective observational cohort study, claims data from a group of small to medium-sized health insurance companies were analysed. Risks for the outcomes thromboembolism, death and major bleeding were estimated by Cox regression. Out of 93,685 patients with atrial fibrillation and a first prescription of an oral anticoagulant, 20,179 receiving VKA and 21,724 ld-DOACs (29.6% of all DOAC patients) were included. For the sensitivity analysis phenprocoumon was compared to the five ld-DOAC groups (ld-apixaban, ld-dabigatran, ld-edoxaban, ld-rivaroxaban, and the composite of all ld-DOACs) after propensity-score matching.

Results

Phenprocoumon was associated with statistically significant fewer thromboembolic events (HR = 1.29, 95% CI [1.13, 1.48], p < .001) and deaths (HR = 1.52, 95% CI [1.41, 1.63], p < .001) and a non-significant higher bleeding risk (HR = 0.89, 95% CI [0.79, 1.00], p = .051) than composite ld-DOAC. Regarding the subgroups, only patients with ld-apixaban had a statistically significant higher risk for thromboembolic events (HR = 1.42, 95% CI [1.21, 1.65], p < .001) and a lower bleeding risk (HR = 0.75, 95% CI [0.65, 0.86], p < .001). Ld-apixaban, ld-edoxaban, and ld-rivaroxaban were associated with a higher risk of death. The sensitivity analysis confirmed these associations.

Conclusion

Phenprocoumon seems to be superior to ld-DOACs for patients with AF. As a hypothesis phenprocoumon might turn out to be the wiser choice for high-risk patients with AF as compared to ld-DOACs, especially regarding thromboembolic events and death. Therefore, RCTs comparing ld-DOACs with phenprocoumon are needed.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12959-022-00389-9.

Vitamin K Antagonist (Phenprocoumon) and Subarachnoid Hemorrhage: A Single-Center, Matched-Pair Analysis

BACKGROUND

Demographic changes are leading to an aging society with a growing number of patients relying on anticoagulation, and vitamin K antagonists (VKA) are still widely used. As mortality and functional outcomes are worse in case of VKA-associated hemorrhagic stroke, phenprocoumon treatment seems to be a negative prognostic factor in case of subarachnoid hemorrhage (SAH). The purpose of this study was to analyze whether phenprocoumon treatment does worsen the outcome after non-traumatic SAH.

METHODS

All patients treated for non-traumatic SAH between January 2007 and December 2016 in our institution were retrospectively analyzed. After exclusion of patients with anticoagulant or antiplatelet treatment other than phenprocoumon, we analyzed 1040 patients. Thirty-three patients (3%) of those were treated with continuous phenprocoumon. In total, 132 out of all 1007 patients without anticoagulant treatment of the remaining patients were matched as control group (ratio = 1:4).

RESULTS

Patients with phenprocoumon treatment were significantly older (66.5 years vs. 53.9 years; p < .0001), and admission status was significantly more often poor (66.7% vs. 41.8%, p = .007) compared to all patients without anticoagulant treatment. Further, bleeding pattern and rates of early hydrocephalus did not differ. Matched-pair analysis revealed a significant higher rate of angio-negative SAH in the study group (p = .001). Overall rates of hemorrhagic or thromboembolic complications did not differ (21.4% vs. 18.8%; NS) but were more often fatal, and 30-day mortality rate was significantly higher in the phenprocoumon group than in patients of the matched-pair control group (33% vs. 24%; p < .001). 30% of the phenprocoumon group and 37% of the matched-pair control group reached favorable outcome. However, poor outcome was strong associated with the reason for phenprocoumon treatment.

CONCLUSION

Patients with phenprocoumon treatment at the time of SAH are significantly older, admission status is worse, and 30-day mortality rates are significantly higher compared to patients without anticoagulant treatment. However, outcome at 6 months did not differ to the matched-pair control group but seems to be strongly associated with the underlying cardiovascular disease. Treatment of these patients is challenging and should be performed on an interdisciplinary base in each individual case. Careful decision-making regarding discontinuation and bridging of anticoagulation and close observation is mandatory.

[Comments on the German consensus statement on prehospital treatment of acute coronary syndrome in patients under long-term treatment with novel oral anticoagulants (NOAC)]

Despite an increasing number of patients suffering from an acute coronary syndrome under novel oral anticoagulant therapy, specific treatment recommendations for anticoagulation are still lacking. For this reason, the German Society of Cardiology and the German Association of Interdisciplinary Intensive Care and Emergency Medicine developed a consensus statement for the treatment of these patients with the aim to summarize the current evidence and to increase the safety of this special patient group.

[Prehospital management of acute coronary syndrome in patients on long-term direct oral anticoagulant treatment]

BACKGROUND

Despite an increasing incidence of patients suffering from acute coronary syndrome (ACS) under simultaneous treatment with direct oral anticoagulants (DOAC), neither sufficient scientific data nor uniform guidelines for the anticoagulation treatment of these patients are currently available.

OBJECTIVE

The aim of this study was to determine the current practice of preclinical treatment of ACS in patients under DOAC treatment.

MATERIAL AND METHODS

An internet and paper-based survey of emergency physicians, specialists of internal medicine, anesthesiologists, emergency and intensive care physicians was performed concerning the prehospital treatment of ACS in patients under long-term DOAC treatment.

RESULTS

Overall, 284 questionnaires were answered. Substantial differences in the current treatment of ACS under long-term DOAC therapy were identified. While 39% of the respondents stated that they administer a combination treatment of heparin and acetylsalicylic acid (ASA), 36% renounced the administration of heparin. If a dose reduction was performed, 71% answered that they reduce the heparin dosage. Also, in cases of ST-segment elevation myocardial infarction 48% of the physicians renounced the administration of heparin.

CONCLUSION

In Germany there is currently a heterogeneous practice of emergency treatment of ACS patients under DOAC therapy with respect to the administration of heparin and ASA. Therefore, guidelines of the specialist medical societies should address the prehospital emergency anticoagulation management of ACS in patients under therapy with DOAC, which correspond to the needs of patients and emergency physicians.

[Spontaneous intraocular hemorrhage under oral anticoagulation : Apixaban in comparison to phenprocoumon]

BACKGROUND

To determine and compare the frequency of intraocular hemorrhage in patients who underwent oral anticoagulation with apixaban or phenprocoumon.

METHODS

A retrospective analysis of patients under oral anticoagulant medication (apixaban or phenprocoumon) seen between January 2015 and June 2015 at the department of ophthalmology, University of Muenster Medical Center was performed. Vitreal or retinal hemorrhage in addition to clinical information including age, gender, best corrected visual acuity, concomitant diseases, concomitant medication and therapy were obtained. Bleeding frequency in both groups was compared using Fisher's exact test.

RESULTS

A total of 172 patients were included with a mean age = 74.0 ± 10.6 years, 57.0% (n = 98) male and 43.0% (n = 74) female. In the phenprocoumon group 147 patients (3.4%, n = 5) developed a retinal or vitreal hemorrhage. In the apxiban group 25 patients (36%, n = 9) developed a retinal or vitreal hemorrhage. There was a significant correlation between the group and bleeding risk (p < 0.001).

CONCLUSION

There was a significant correlation between medication (apixaban vs. phenprocoumon) and bleeding risk in this study population. Further studies with more patients especially in patients with a high risk of hemorhage, age-related macular degeneration (AMD) and proliferative diabetic retinopathy are needed.

[Management of anticoagulants in ophthalmic surgery-a survey among ophthalmic surgeons in Germany]

INTRODUCTION

As our population ages and comorbidities rise, ophthalmic surgeons are increasingly faced with patients on anticoagulant therapy or with clotting disorders. The ophthalmic surgeon has to weigh the perioperative risk of haemorrhage when anticoagulation continues against the risk of thromboembolism caused by discontinuation or changing the patient's medication (bridging, switching, cessation). There are currently no guidelines or recommendations.

METHODS

A survey was sent to the DOG (German Ophthalmologic Society) divisions and associated surgical organizations to determine the status quo. A questionnaire was sent out and filled out by the different groups of specialists.

RESULTS

All four divisions of the DOG and four associated organizations returned completed questionnaires. Surgical interventions were listed that are carried out during anticoagulant therapy without exceptions, as well as interventions that were classified to require medical adjustment. Although the assessments varied, general consensus was achieved regarding interventions not requiring adjustments due to anticoagulants (i. e., intravitreal injection, cataract surgery, laser and corneal operations, simple muscle surgery), and those interventions requiring adjustments in medications (glaucoma operations, complex retina surgery, eye socket surgery, complex surgery of the lid).

CONCLUSION

Main result of this survey was the specification of serious bleeding complications which are permanent vision loss and re-operation. They could serve as endpoint parameters for essential future investigations. Nevertheless, this survey makes clear that the decision about an adjustment of anticoagulant medication in ophthalmic surgery is currently made individually and not based on established standards.

Comparative effectiveness of rivaroxaban versus a vitamin K antagonist in patients with renal impairment treated for non-valvular atrial fibrillation in Germany - A retrospective cohort study

Background

The risk of thromboembolic events is increased in patients with non-valvular atrial fibrillation (NVAF) and renal impairment. The risk of bleeding events is increased if these patients are treated with anticoagulants and further increased in those with active cancer.

Methods

RELOAD, a retrospective database study, assessed the outcomes of patients with NVAF prescribed rivaroxaban versus phenprocoumon. Here, we present a subgroup analysis evaluating effectiveness and safety of rivaroxaban versus phenprocoumon in patients with NVAF and renal impairment. Analyses were additionally stratified by patients with and without evidence of cancer at baseline.

Results

When using the ‘one tablet per day’ definition of estimating drug exposure time, the incidence of the primary endpoint of ischaemic stroke was significantly lower in patients (without evidence of cancer at baseline) receiving rivaroxaban 15 mg or 20 mg once daily versus those receiving phenprocoumon (2.40 vs 3.51 events per 100 patient-years, respectively; hazard ratio [HR] = 0.72, 95% confidence interval [CI] 0.55–0.94, p = 0.015); with the incidence of the primary safety outcome of intracranial haemorrhage being numerically lower (0.57 vs 0.89 events per 100 patient-years, respectively; HR = 0.66, 95% CI 0.38–1.14, p = 0.14). Similar results were observed when using the ‘empirical defined daily dose’ definition to estimate drug exposure time and when including patients with evidence of cancer.

Conclusion

The prescription of rivaroxaban in patients with NVAF and renal impairment was associated with a lower incidence of ischaemic stroke and intracranial haemorrhage versus phenprocoumon in patients without evidence of cancer.

Shorter hospital stays in epistaxis patients with atrial fibrillation when taking rivaroxaban or apixaban versus phenprocoumon

Patients taking oral anticoagulants (OACs) currently represent one-third of all patients treated for epistaxis and an upward trend is expected. New direct oral anticoagulants (DOACs) have been on the market for approximately 10 years. DOACs are favoured over Vitamin K-Antagonists (VKAs) in the current guidelines. There are barely studies that investigate the impact of DOACs on patients with epistaxis. A retrospective study was performed analysing all patients who had stationary treatment for epistaxis from 01.01.2011 to 01.01.2018 in a tertiary care centre. In a total of 466 patients, 46.1% were on OACs. The main indication was atrial fibrillation (AF, 67.4%).The number of DOACs taken surpassed that of the VKAs during the past 2 years. The length of hospital stay was significantly longer in the phenprocoumon group (3 ± 0.2 days) in comparison to both the rivaroxaban (2.3 ± 0.1) and the apixaban (2.2 ± 0.1) groups (p = 0.005). Posterior epistaxis occurred more frequently in the phenprocoumon group (10.8%) than in the rivaroxaban (0%) and apixaban (0%) groups (p = 0.03). A correlation between CHA₂DS₂-VASc score (risk score for apoplexy in patients with AF, p = 0.01), HAS-BLED score (score for assessment of major bleeding in patients taking anticoagulants with AF, p = 0.006), and length of hospital stay (p = 0.002) with recurrence of epistaxis was found. Shorter hospital stays and exclusively anterior bleeding was noted in AF patients taking rivaroxaban and apixaban, whereas AF patients taking phenprocoumon stayed in hospital longer and had more posterior bleeding.

Characteristics, treatment and outcome of bleeding after tooth extraction in patients on DOAC and phenprocoumon compared to non-anticoagulated patients-a retrospective study of emergency department consultations

OBJECTIVES

Bleeding after tooth extraction range from minor bleeding to life-threating haemorrhagic shock and are among the leading complications in patients under oral anticoagulation with direct oral anticoagulants (DOACs) or phenprocoumon. Little is known about how anticoagulation in patients under DOAC or phenprocoumon alters the characteristics, treatment or outcome of bleeding events, in comparison to non-anticoagulated patients.

METHODS

Patients admitted to a tertiary ED in Bern, Switzerland, from June 1st 2012 to 31st May 2016 with bleeding related to tooth extraction under DOAC, phenprocoumon or without anticoagulation, were compared.

RESULTS

Out of 161,458 emergency consultations, 64 patients with bleeding from tooth extraction were included in our study. In anticoagulation groups, we found significantly more delayed bleeding events than in patients without anticoagulation (9 (81.3%) DOAC, 19 (86.4%) phenprocoumon, 8 (30.8%) no anticoagulation, p < 0.001). Anticoagulated patients had to stay longer in the ED than non-anticoagulated patients, with no significant difference between DOAC or phenprocoumon (hours: 4.8 (3.2-7.6 IQR) DOAC, 3.0 (2.0-5.5 IQR) phenprocoumon, p = 0.133; 2.7 (1.6-4.6) no anticoagulation; p = 0.039). More patients with anticoagulation therapy needed surgery than patients without anticoagulant therapy (11 (68.8%) DOAC, 12 (54.6%) VKA, p = 0.506; 7(26.9%) no anticoagulation; p = 0.020).

CONCLUSIONS

Delayed bleeding occur more often in anticoagulated patients with both DOAC and phenprocoumon compared to patients without anticoagulation. Bleeding events in anticoagulated patients with DOAC and phenprocoumon equally need longer ED treatment and more frequent surgical intervention.

CLINICAL RELEVANCE

Caution with delayed bleeding in anticoagulated patients with DOACs and phenprocoumon is necessary and treatment of bleeding is resource-demanding.

[Anticoagulation in patients with chronic kidney disease : Recommendations from the working group "Heart-Kidney" of the German Cardiac Society and the German Society of Nephrology]

Indications for anticoagulation are thromboembolic events, prosthetic heart valves, and atrial fibrillation with a corresponding risk score. Clinical trials have excluded patients with advanced chronic kidney disease and these data cannot be always generalized to patients with chronic kidney disease. Non-vitamin K antagonist oral anticoagulants (NOACs) are mostly not recommended or are contraindicated in advanced stages of chronic kidney disease. Observational studies have shown that dialysis patients with atrial fibrillation do not profit from coumarin anticoagulants; prospective studies are lacking.

Apixaban, rivaroxaban, and dabigatran use in patients undergoing catheter ablation for atrial fibrillation using the second-generation cryoballoon

BACKGROUND

Data are limited on the safety of periprocedural anticoagulation with novel oral anticoagulants (NOACs) in patients undergoing pulmonary vein isolation (PVI) using the second-generation cryoballoon (CB) for the treatment of atrial fibrillation.

HYPOTHESIS

We hypothesized that the incidence of acute periprocedural complications in patients undergoing PVI do not differ between patients treated with VKA compared to NOACs.

METHODS

In 200 consecutive patients (mean age, 64.3 _ 10.6 years; female, n = 83) with symptomatic atrial fibrillation, PVI using the second-generation 28-mm CB was performed. In patients treated with NOACs, the medication was stopped the day of the procedure and continued the evening after the procedure with a reduced dosage. Patients treated with phenprocoumon were continued on uninterrupted phenprocoumon with a target INR of 2 to 3. If INR was <2, bridging with low-molecular-weight heparin was performed.

RESULTS

Forty-seven of 200 patients (23.5%) were treated with a vitamin K antagonist (VKA) and 55 (27.5%) were treated with apixaban, 67 (33.5%) with rivaroxaban, and 31 (15.5%) with dabigatran. Seven (3.5%) major complications occurred in the overall population. Major bleeding complications did not differ significantly between the 2 groups (P = 0.23). One patient taking VKA had a pericardial tamponade at the end of the procedure; 2 patients treated with apixaban developed a groin hematoma requiring surgical intervention. Transient ischemic attack occurred in 1 patient of the apixaban and rivaroxaban group.

CONCLUSIONS

Apixaban, rivaroxaban, and dabigatran, compared with uninterrupted VKA, did not show a higher risk for major bleeding or ischemic complications in patients undergoing PVI using the second-generation CB.

Comparative risk of major bleeding with new oral anticoagulants (NOACs) and phenprocoumon in patients with atrial fibrillation: a post-marketing surveillance study

BACKGROUND

Non-vitamin K antagonist oral anticoagulants (NOACs) are at least as effective and safe as vitamin K antagonists (VKAs) for stroke prevention in atrial fibrillation (AF). All pivotal trials have compared NOACs to warfarin. However, other VKAs are commonly used, for instance phenprocoumon.

PATIENTS AND METHODS

A retrospective cohort study using a German claims database assessed the comparative risks of bleeding leading to hospitalization during therapy with NOACs and phenprocoumon in AF patients. Endpoints consisted of major bleeding, gastrointestinal bleeding, and any bleeding. Data were collected from January 1, 2013 to March 31, 2015. Patients newly initiated on dabigatran, apixaban, rivaroxaban, or phenprocoumon were included. Hazard Ratios for bleeding events were derived from Cox proportional hazard models, adjusting for differences in baseline characteristics. Propensity score matching was performed as a sensitivity analysis.

RESULTS

A total of 35,013 patients were identified, including 3138 on dabigatran, 3633 on apixaban, 12,063 on rivaroxaban, and 16,179 on phenprocoumon. Patients prescribed apixaban or phenprocoumon were older compared to those on dabigatran or rivaroxaban and had a higher CHA₂DS₂-VASc score. After adjusting for baseline confounders, apixaban was associated with lower risks of major bleeding (HR 0.68, 95% CI 0.51-0.90, p = 0.008), gastrointestinal bleeding (HR 0.53, 95% CI 0.39-0.72, p < 0.001), and any bleeding (HR 0.80, 95% CI 0.70-0.92, p = 0.002) compared to phenprocoumon. There were no significant differences in bleeding risk between dabigatran and phenprocoumon. Rivaroxaban was associated with more gastrointestinal bleeding (HR 1.39, 95% CI 1.21-1.60, p < 0.001) and any bleeding (HR 1.19, 95% CI 1.10-1.28, p < 0.001). Sensitivity analysis using propensity score matching confirmed these observations.

CONCLUSIONS

Apixaban therapy is associated with a significantly reduced risk of bleeding compared to phenprocoumon. Bleeding risk with dabigatran was similar to that of phenprocoumon but bleeding risk with rivaroxaban was higher.

Genetic variations of phenprocoumon metabolism in patients with ventricular assist devices

OBJECTIVES

Anticoagulation in patients with ventricular assist device (VAD) support is crucial and to date, no alternative to vitamin K antagonists (VKAs) can be safely used. Genetic variances of cytochrome p450 2C9 (CYP2C9) and vitamin K epoxide reductase (VKORC) have been recently connected with variation of VKA maintenance as well as loading doses. In this retrospective study, we assessed the incidence of genetic variations and the influence of different genotypes of CYP2C9 and VKORC1 in VAD patients.

METHODS

A total of 161 patients received a VAD implant in our institution between January 2006 and July 2014. Of these, 63 consented to genetic analysis and completed an interview with standardized questions on phenprocoumon (PC) dosage, international normalized ratio and anticoagulation-related complications. Determination of VKORC (-1639 G > A; -1173 C > T) and of CYP2C9 (*2, 430 C > T; *3, 1075 A > C) polymorphisms was performed by polymerase chain reaction and restriction analysis.

RESULTS

The most common VKORC-1639 allele combination was wild-type GG (41%) followed by GA (32%) and AA (27%). Patients with VKORC1 polymorphisms AA and GA needed less PC in the maintenance phase of anticoagulation (P < 0.001) compared with wild-type GG patients. In contrast, CYP2C9 polymorphisms showed no effect on PC doses. Similar findings were observed in the initiation phase of PC therapy. High complications rates under PC therapy were observed particularly at the beginning.

CONCLUSIONS

VKORC polymorphism affects PC dosage in the initiation as well as the maintenance phase. High rates of bleeding complications and thromboembolic events were found at the beginning of PC therapy in VAD patients. Therefore, a genotype-guided dosage algorithm might be useful in VAD patients.

Postoperative bleeding risk for cutaneous surgery in the head and neck region with continued phenprocoumon therapy

In a total of 171 surgical procedures for lesions in the head and neck region in patients in whom phenprocoumon therapy was not stopped, 16 (9%) postoperative bleeding events were observed over a follow-up period of two weeks. Local measures were sufficient in all cases except one severe case where blood transfusion was needed and anticoagulant treatment was stopped for 7 days. The bleeding risk was significantly higher for the surgical procedures of the nose than those in other areas (21% versus 6%, P = 0.014), but was not influenced by the international normalized ratio (INR) of blood coagulation, size, site and type of the lesion, surgical procedure, and sex and age of the patients. The bleeding rate in patients not on any anticoagulation therapy was significantly lower (6/211 = 3%). Across both groups, just over 80% of the bleeding episodes were within the first two days (55% on the same day and 32% on the next day) of the surgery. No bleeding was recorded after 5 days. Our data suggest that cutaneous surgery in the head and neck region can be safely performed with continued phenprocoumon therapy in most cases in an INR range of 1.3-3.4, but rarely severe bleeding does occur and can be managed with a close-contact follow-up and with 24-h on call services during the first two days postoperatively.

Risk factors and management of anticoagulant-induced intramural hematoma of the gastrointestinal tract

INTRODUCTION

Intramural intestinal hematoma is considered a rare complication of overanticoagulation in elderly patients. Nevertheless, this clinical entity is increasingly being reported in the literature, and its incidence is predicted to increase further as a result of the wide use of long-term anticoagulation in an aging population. However, data regarding the risk factors and optimal management of this unusual complication in patients on phenprocoumon/warfarin are scarce.

PATIENTS AND METHODS

We retrospectively analyzed the medical reports of patients with intramural gastrointestinal hematoma on anticoagulant therapy who were treated in our unit between January 2008 and July 2011.

RESULTS

Four consecutive patients were identified during the study period. The mean age of the patients was 80 years. All patients were on uninterrupted anticoagulation with phenprocoumon due to chronic atrial fibrillation. Hematoma was localized in the duodenum in one patient, in the jejunum in two patients, and in the rectum in one patient. Hematoma occurred spontaneously in three patients and following a trauma in one patient. Excessive anticoagulation with an INR of >6 was associated with the development of this complication in all spontaneous cases. A combination of computed tomography and sonography established the diagnosis in all four. Conservative therapy proved successful in two patients, and surgery was necessary in two cases.

CONCLUSION

Intramural hematoma of the gastrointestinal tract should be suspected in any patient with abdominal pain or intestinal obstruction under anticoagulant therapy. Emergency physicians and surgeons should be aware of this rare complication, as most such cases will resolve spontaneously under conservative measures without the need for surgery.