Hemorrhagic complications of anticoagulant treatment

Increased risk of high-grade hemorrhage in cancer patients treated with gemcitabine: a meta-analysis of 20 randomized controlled trials

Purpose

Gemcitabine, a third-generation anticancer agent, has been shown to be active in several solid tumors. High-grade hemorrhage (grade≥3) has been reported with this drug, although the overall risk remains unclear. We conducted a meta-analysis of randomized controlled trials evaluating the incidence and risk of high-grade hemorrhage associated with gemcitabine.

Methods

Pubmed was searched for articles published from January 1, 1990 to December 31, 2012. Eligible studies included prospective randomized controlled phase II and III trials evaluating gemcitabine-based vs non-gemcitabine-based therapy in patients with solid tumors. Data on high-grade hemorrhage were extracted. Overall incidence rates, relative risk (RR), and 95% confidence intervals (CI) were calculated employing fixed- or random-effects models depending on the heterogeneity of included trials.

Results

A total of 6433 patients from 20 trials were included. Among patients treated with gemcitabine-based chemotherapy, the overall incidence of high-grade hemorrhage was 1.7% (95%CI: 0.9–3.1%), and the RR of high-grade hemorrhage was 2.727 (95%CI: 1.581–4.702, p<0.001). Exploratory subgroup analysis revealed the highest RR of hemorrhage in non-small-cell lung cancer (NSCLC) patients (RR: 3.234; 95%CI, 1.678–6.233; p<0.001), phase II trials (RR 7.053, 95%CI: 1.591–31.27; p = 0.01), trials reported during 2006–2012 (RR: 3.750; 95%CI: 1.735–8.108, p<0.001) and gemcitabine used as single agent (RR 7.48; 95%CI: 0.78–71.92, p = 0.081).

Conclusion

Gemcitabine is associated with a significant increase risk of high-grade hemorrhage in patients with solid tumors when compared with non-gemcitabine-based therapy.

Plasminogen activators and ischemic stroke: conditions for acute delivery

Appropriate acute treatment with plasminogen activators (PAs) can significantly increase the probability of minimal or no disability in selected ischemic stroke patients. There is a great deal of evidence showing that intravenous recombinant tissue PAs (rt-PA) infusion accomplishes this goal, recanalization with other PAs has also been demonstrated in the development of this treatment. Recanalization of symptomatic, documented carotid or vertebrobasilar arterial territory occlusions have also been achieved by local intra-arterial PA delivery, although only a single prospective double-blinded randomized placebo-controlled study has been reported. The increase in intracerebral hemorrhage with these agents by either delivery approach underscores the need for careful patient selection, dose-appropriate safety and efficacy, proper clinical trial design, and an understanding of the evolution of cerebral tissue injury due to focal ischemia. Principles underlying the evolution of focal ischemia have been expanded by experience with acute PA intervention. Several questions remain open that concern the manner in which PAs can be applied acutely in ischemic stroke and how injury development can be limited.

Transitions of care in patients receiving oral anticoagulants: general principles, procedures, and impact of new oral anticoagulants

BACKGROUND

Most patients requiring anticoagulation therapy while hospitalized will continue this therapy as outpatients. This transition can be associated with gaps in care related to anticoagulation therapy that increase the risk of adverse events, rehospitalizations, and death. Warfarin, the most commonly used oral anticoagulant, presents distinct management challenges, including drug-food and drug-drug interactions, a narrow therapeutic window, and the requirements for periodic blood monitoring and dose adjustments, particularly during the hospital discharge process.

PURPOSE

This review explores clinical challenges and potential solutions surrounding anticoagulation therapy with warfarin during transitions of care, as well as discusses newer anticoagulants that are approved or are in late stages of development for the prevention of thromboembolic events.

CONCLUSIONS

Diligence, careful planning, and close communication between patients and healthcare providers during and after discharge are required to ensure that patients remain adequately and safely anticoagulated with warfarin in the outpatient setting. New oral anticoagulants may offer the possibility of safer and simpler care for patients requiring anticoagulation.

CLINICAL IMPLICATIONS

We summarize the latest guidelines and recommendations for safe hospital discharge and apply them to the specific case of discharging a warfarin-treated patient. In addition, we discuss the new oral anticoagulants and their potential to offer more efficacious and easier-to-manage anticoagulation.

Effect of Rosuvastatin on Warfarin Pharmacodynamics and Pharmacokinetics

The effect of rosuvastatin on warfarin pharmacodynamics and pharmacokinetics was assessed in 2 trials. In trial A (a randomized, double-blind, 2-period crossover study), 18 healthy volunteers were given rosuvastatin 40 mg or placebo on demand (o.d.) for 10 days with 1 dose of warfarin 25 mg on day 7. In trial B (an open-label, 2-period study), 7 patients receiving warfarin therapy with stable international normalized ratio values between 2 and 3 were coadministered rosuvastatin 10 mg o.d. for up to 14 days, which increased to rosuvastatin 80 mg if the international normalized ratio values were <3 at the end of this period. The results indicated that rosuvastatin can enhance the anticoagulant effect of warfarin. The mechanism of this drug-drug interaction is unknown. Rosuvastatin had no effect on the total plasma concentrations of the warfarin enantiomers, but the free plasma fractions of the enantiomers were not measured. Appropriate monitoring of the international normalized ratio is indicated when this drug combination is coadministered.

Parecoxib Sodium, an Injectable COX-2-Specific Inhibitor, Does Not Affect Unfractionated Heparin-Regulated Blood Coagulation Parameters

The objective of this study was to evaluate the potential for hemostatic interaction between a full analgesic dose of parecoxib sodium (parecoxib), a prodrug of the COX-2 specific inhibitor valdecoxib, and unfractionated heparin (UFH) in healthy male subjects. This open-label, single-center study comprised two treatment periods. In treatment period I, fasted, eligible subjects (n = 18) received a UFH bolus (4000 U) followed by a 36-hour UFH infusion (start dose 10-14 U/kg). Activated partial thromboplastin time (aPTT), prothrombin time (PT), and platelet counts were measured at regular intervals up to 24 hours after the end of the UFH infusion. After a 2-day washout, patients randomized to treatment period II received a full analgesic dosage of parecoxib 40 mg bid intravenously (IV) for 6 days (n = 18), with concomitant UFH (same regimen as treatment period I) on day 5 (n = 18). APTT, PT, and platelet counts were evaluated at regular intervals up to 24 hours after UFH infusion. Coadministration of parecoxib 40 mg bid IV with UFH (treatment period II) had no significant effect on aPTT, PT, or platelet counts, which were similar to those of participants receiving UFH alone (treatment period I) at all time points. These results show that a full analgesic dose of parecoxib, a COX-2-specific inhibitor available for parenteral administration, can be coadministered with UFH without affecting blood coagulation parameters. Therefore, parecoxib may be administered to patients who are receiving UFH for thromboprophylaxis.

Adverse drug events associated with vitamin K antagonists: factors of therapeutic imbalance

Background

Adverse drug events (ADE) occur frequently during treatment with vitamin K antagonists (AVK) and contribute to increase hemorrhagic risks.

Methods

A retrospective study was conducted over a period of 2 years. Patients treated with AVK and admitted to the emergency room of a tertiary care hospital in Beirut were included. The aim of the study was to identify ADE characterized by a high international normalized ratio (INR) and to determine the predictive factors responsible for these events. Statistical analysis was performed with the SPSS statistical package.

Results

We included 148 patients. Sixty-seven patients (47.3%) with an INR above the therapeutic range were identified as cases. The control group consisted of 81 patients (54.7%) with an INR within the therapeutic range. Hemorrhagic complications were observed in 53.7% of cases versus 6.2% of controls (P < 0.0001). No significant difference was noticed between cases and controls regarding the indication and the dose of AVK. Patients aged over 75 years were more likely to present an INR above the therapeutic range (58.2%, P = 0.049). Recent infection was present in 40.3% of cases versus 6.2% of controls (P < 0.0001) and hypoalbuminemia in 37.3% of cases versus 6.1% of controls (P < 0.0001). Treatment with antibiotics, amiodarone, and anti-inflammatory drugs were also factors of imbalance (P < 0.0001).

Conclusion

Many factors may be associated with ADE related to AVK. Monitoring of INR and its stabilization in the therapeutic range are important for preventing these events.

[Massive subretinal hemorrhage and anticoagulants. An unfortunate combination?]

Exudative age-related macular degeneration (ARMD) is one of the conditions which has been shown to be associated with a risk of massive subretinal hemorrhage. Patients with thick submacular hemorrhage complicating ARMD typically have a poor visual prognosis. Antiplatelet therapy with aspirin, clopidogrel or ticlopidine has significant benefits in the secondary prevention of fatal and non-fatal coronary and cerebrovascular events. Anticoagulation is frequently used in this elderly age group for a variety of other comorbidities including prosthetic heart valves, atrial fibrillation, ischemic heart disease, cerebrovascular disease and venous thromboembolism. However, it is a well established observation that the longer patients remain on anticoagulant therapy, the higher the cumulative risk of bleeding. Over the past years, there has been a rapidly growing body of literature concerning the risk of hemorrhagic ocular complications with ophthalmic surgery in patients receiving anticoagulant therapy. By contrast, there are still little data on the relationship between anticoagulation or antiplatelet therapy and spontaneous ocular hemorrhages and only few reports have focused on patients with ARMD. Just recently, several authors reported a strong association of anticoagulants and antiplatelet agents with the development of large subretinal hemorrhages in ARMD patients. Moreover, arterial hypertension is a high risk factor for large subretinal hemorrhages in ARMD patients receiving anticoagulants or antiplatelet agents. Physicians should be aware of an increased risk of extensive subretinal hemorrhage in ARMD patients when deciding on the initiation and duration of anticoagulant and antiplatelet therapy.

Warfarin-antibiotic interactions in older adults of an outpatient anticoagulation clinic

BACKGROUND

Several classes of drugs, such as antibiotics, may interact with warfarin to cause an increase in warfarins anticoagulant activity and the clinical relevance of warfarin-antibiotic interactions in older adults is not clear.

OBJECTIVE

The aim of this study was to determine the effect of oral antibiotics, such as amoxicillin, azithromycin, cephalexin, ciprofloxacin, levofloxacin, and moxifloxacin, on the international normalized ratio (INR) in patients ≥65 years on stable warfarin therapy. The secondary objective was to compare the effect of warfarin-antibiotic interactions on outcomes of overanticoagulation.

METHODS

Data for this retrospective cohort study were collected through a medical record review of patients in an outpatient anticoagulation clinic of a Veterans Affairs medical center. Patients aged ≥65 years on stable warfarin therapy and with at least 1 prescription of an oral antibiotic of interest during the period from January 1, 2003 to March 1, 2011 were included. A mixed-effects repeated-measures ANOVA model was used to determine the effect of antibiotics on the mean change in patients' INR. The Fisher exact test was used to determine the association between the antibiotics and secondary outcomes of overanticoagulation, using cephalexin as the control. Statistical significance was defined as a P value <0.05.

RESULTS

A total of 205 patients had 364 prescriptions for warfarin and antibiotics concomitantly, and there was a significant interaction between antibiotic and time (F(15, 358) = 1.9; P = 0.0221). Antibiotics with a significant increase in INR were amoxicillin (P = 0.0019), azithromycin (P < 0.0001), ciprofloxacin (P = 0.002), levofloxacin (P < 0.0001) and moxifloxacin (P < 0.0001). There was a significant association between type of antibiotic and secondary outcomes of overanticoagulation.

CONCLUSIONS

In older patients on stable warfarin therapy, antibiotics may lead to an increase in INR. However, this may not result in clinically significant outcomes of bleeding or hospitalization, suggesting that antibiotics may be prescribed for older adults taking warfarin as long as their INR is being routinely monitored.

Percutaneous Closure of the Left Atrial Appendage

This article reviews the published evidence on stroke prevention with percutaneous closure of the left atrial appendage and provides comparative insight into the various left atrial appendage closure devices currently in development.

Quadruple Valve Replacement with Mechanical Valves: An 11-Year Follow-up Study

<p><b>Background:</b> We performed the first quadruple valve replacement with mechanical valves, combined with the correction of complex congenital heart disease on November 17, 1999. We report here the 11-year follow-up study.</p><p><b>Methods:</b> A 47-year-old man with subacute rheumatic endocarditis, a ventricular septal defect, and an obstruction of the right ventricular outflow tract required replacement of the aortic, mitral, tricuspid, and pulmonary valves; repair of the ventricular septal defect; and relief of the obstruction of the right ventricular outflow tract. The surgery was done on November 17, 1999, after careful systemic preparation of the patient. Warfarin therapy with a target international normalized ratio (INR) range of 1.5 to 2.0 was used. Follow-up included monitoring the INR, recording the incidences of thromboembolic and bleeding events, electrocardiography, radiography, and echocardiography evaluations.</p><p><b>Results:</b> The patient's INR was maintained between 1.5 and 2.0. All 4 mechanical prosthetic heart valves worked well. He is in generally good health without any thromboembolic or bleeding complications.</p><p><b>Conclusions:</b> Long-term management is challenging for patients who have experienced quadruple valve replacement with mechanical valves; however, promising results could mean that replacement of all 4 heart valves in 1 operation is feasible in patients with quadruple valve disease, and an INR of 1.5 to 2.0 could be appropriate for Chinese patients with undergoing valve replacement with mechanical valves.</p>

Pharmacokinetic and pharmacodynamic variability of fluindione in octogenarians

In the PREPA observational study, we investigated the factors influencing pharmacokinetic and pharmacodynamic variability in the responses to fluindione, an oral anticoagulant drug, in a general population of octogenarian inpatients.Measurements of fluindione concentrations and international normalized ratio (INR ) were obtained for 131 inpatients in whom fluindione treatment was initiated. Treatment was adjusted according to routine clinical practice. The data were analyzed using nonlinear mixed-effects modeling, and the parameters were estimated using MONOLI X 3.2. The pharmacokinetics (PK) of fluindione was monocompartmental, whereas the evolution of INR was modeled in accordance with a turnover model (inhibition of vitamin K recycling). Interindividual variability (II V) was very large. Clearance decreased with age and with prior administration of cordarone. Patients who had undergone surgery before the study had lower IC50 values, leading to an increased sensitivity to fluindione. Pharmacokinetic exposure is substantially increased in elderly patients, warranting a lower dose of fluindione.

Effect of pitavastatin vs. rosuvastatin on international normalized ratio in healthy volunteers on steady-state warfarin

OBJECTIVE

Statins have been shown to impact international normalized ratio (INR) when coadministered with warfarin. The aim of this study was to assess the effect of pitavastatin compared with rosuvastatin on steady-state pharmacodynamics (PD) of warfarin by measuring INR in healthy adult subjects.

METHODS

Subjects received oral doses of warfarin 5 mg once daily on days 1 through 3. The dose was titrated on days 4 through 9 to reach a steady-state INR of 1.5 to 2.2. Warfarin was continued on days 10 through 21 and pitavastatin 4 mg or rosuvastatin 40 mg was administered once daily on days 14 through 22. After a 14-day washout period, the process was repeated with the alternate statin. STUDY NUMBER: NK-104-4.03US.

RESULTS

For pitavastatin, mean INR changed from 1.73 ± 0.18 (n = 42) on day 14 before starting statin dosing, to 1.78 ± 0.29 (n = 42) on day 22 at treatment end; the difference in INR was not significant (p = 0.219). For rosuvastatin, mean INR increased significantly from 1.74 ± 0.20 (n = 43) at baseline to 1.90 ± 0.30 (n = 43) at treatment end (p < 0.001). Rosuvastatin caused a significantly greater increase in INR than pitavastatin (p < 0.001).

CONCLUSION

Steady-state INR during warfarin treatment did not change significantly when pitavastatin 4 mg was added to the regimen, while a significant increase was observed when rosuvastatin 40 mg was added. The effect of rosuvastatin on INR was significantly larger than the effect of pitavastatin. This study is limited because it was done in healthy volunteers. Further studies in patient populations are needed to better understand the clinical significance of the results.

Association of apolipoprotein E genotype with duration of time to achieve a stable warfarin dose in African-American patients

STUDY OBJECTIVE

To test the hypothesis that genotypes for proteins affecting vitamin K availability influence the duration of time required to achieve a stable warfarin dose in African-American patients.

DESIGN

Retrospective cohort study.

SETTING

Pharmacist-managed antithrombosis clinic.

PATIENTS

Ninety-two African-American adults whose warfarin therapy was initiated between September 2, 1999, and July 8, 2009.

MEASUREMENTS AND MAIN RESULTS

During a routine anticoagulation clinic visit, a sample was collected from each patient for genetic analysis. genotyping was performed for the following variants: apolipoprotein E ε2, ε3, and ε4; NAD(P)H:quinone oxidoreductase (NQO1)*2; cytochrome P450 (CYP) 4F2 V433M; CYP2C9*2, *3, *5, *8, and *11; and vitamin K epoxide reductase complex 1 (VKORC1) -1639G>A. Patients' medical records were then reviewed, and data were collected retrospectively for each anticoagulation clinic visit during the first 6 months of warfarin therapy or until dose stabilization. The median time required to reach a stable warfarin dose, defined as the dose that produced therapeutic anticoagulation for three consecutive clinic visits, was 83 days. Compared with the 46 patients who achieved a stable warfarin dose within 83 days, the 46 patients who required longer durations for dose stabilization had a higher frequency of the apolipoprotein E ε3/ε3 genotype (37% vs 59%, p=0.037). Sixty-one percent of patients with the ε3/ε3 genotype versus 40% of those with an ε2 or ε4 allele had a delay in achieving a stable dose (p=0.037). Neither the CYP4F2 nor NQO1 genotype was associated with warfarin dose stabilization.

CONCLUSION

Our data support the hypothesis that the apolipoprotein E genotype is associated with duration of time to reach a stable warfarin dose in African-American patients. Further insight into the genetic effects on warfarin dose stabilization could reveal novel methods to improve anticoagulation control during the warfarin initiation period.

Risk factors of vitamin K antagonist overcoagulation

OBJECTIVES

The aims of this prospective study were to identify, in vitamin K antagonist (VKA)-treated patients, factors associated with INR values: (i) greater than 6.0. and (ii) ranging from 4.0 to 6.0 complicated with bleeding. We also assessed VKA-related morbidity in these patients.

METHODS

During a 6-month period, 3090 consecutive patients were referred to our Department of Internal Medicine, including 412 VKA-treated patients. At admission, the medical records of VKA-treated patients were reviewed for type, duration and indication of VKA therapy, previous medical history of VKA-related hemorrhage, comorbidities and concomitant medications.

RESULTS

Forty of the 412 VKA-treated patients (9.7%) exhibited oral anticoagulant related overcoagulation. VKA overcoagulation was associated with high morbidity, leading to major bleeding in 27.5% of cases; moreover, 12.5% of these patients died, death being mainly due to major bleeding. Under multivariate analysis, significant factors for VKA-related overcoagulation were as follows: previous medical history of VKA therapy-related hemorrhage (P=0.00001) and INR levels over therapeutic range (P=0.0006), chronic liver disease (P=0.03), therapy with amiodarone (P=0.009); in contrast, statin therapy was found to be a protective factor of VKA overcoagulation (P=0.008).

CONCLUSIONS

The knowledge of predictive factors of VKA-related overcoagulation seems of utmost importance to improve patients' management. Our study underlines the fact that the potential of drug interaction should be taken into account when choosing amiodarone for patients receiving VKAs. Interestingly, long-term (>6 month) statin therapy may be a protective factor of VKA overcoagulation. Our findings, therefore, suggest that there may be no need to switch long-term users of VKA and statin to a safer alternative therapy.

Risks related with withholding and resuming anticoagulation in patients with non-variceal upper gastrointestinal bleeding while on warfarin therapy

BACKGROUND

The use of warfarin is growing for the prevention or treatment of cardiovascular or cerebrovascular diseases. The risk of haemorrhagic side effects is increased in patients taking warfarin.

AIMS

To evaluate risks related with withholding and resuming anticoagulation in patients with upper gastrointestinal bleeding (UGIB) while on warfarin therapy and the role of the second-look endoscopic examination (SEE).

METHODS

Records of 58 patients with native valvular heart diseases who presented with non-variceal UGIB during chronic anticoagulation with warfarin were retrospectively reviewed. Age- and gender-matched patients with non-variceal UGIB during aspirin therapy because of ischaemic heart disease were recruited as the control group.

RESULTS

Development of both recurrent bleeding and thromboembolic events were more frequent in warfarin group than in control group (7.0% vs. 0% with p = 0.03 and 16.7% vs. 2.4% with p < 0.01, respectively). One of four cases of recurrent bleeding in warfarin group was found by SEE performed in an asymptomatic patient. There were six thromboembolic events which occurred on the 21st, 27th, 28th, 31st, 58th and 75th day from the presentation out of 36 patients who ceased anticoagulation. In contrast, only one from 41 in whom aspirin was discontinued experienced myocardial infarction. There was no difference in the failure of endoscopic haemostasis necessitating angiographic embolisation or surgery, hospital stay, the need of transfusion and overall mortality.

CONCLUSIONS

Anticoagulation is recommended to be resumed before the 20th day from the cessation to prevent thromboembolic events. A routine SEE before resuming anticoagulation might be helpful to detect asymptomatic recurrent bleeding.

Warfarin management after discharge from hospital: a qualitative analysis

WHAT IS KNOWN AND OBJECTIVE

Warfarin is recognized as a high-risk medication for adverse events, and the risks are particularly heightened in the period immediately following a patient's discharge from hospital. This qualitative study aimed to explore the experiences of Australian patients and healthcare professionals of warfarin management in the post-discharge period and identify the benefits and deficiencies of existing systems, to inform the development of a model for a new collaborative post-discharge warfarin management service.

METHODS

Healthcare professionals, professional organization representatives and patients recently discharged from hospital taking warfarin (consumers) were recruited via purposive, criterion-based sampling within two Australian states. Semi-structured telephone interviews were conducted between August and October 2008 using standard discussion guides. Data were manually analyzed to identify emergent themes using a phenomenological approach.

RESULTS

Forty-seven participants were involved in the telephone interviews. Three major themes emerged: (i) appropriate warfarin education is integral to effective warfarin management, (ii) problems occur in communication along the continuum of care and (iii) home-delivered services are valuable to both patients and healthcare professionals.

DISCUSSION

Although high-quality warfarin education and effective communication at the hospital-community interface were identified as important in post-discharge warfarin management, deficiencies were perceived within current systems. The role of home-delivered services in ensuring timely follow-up and promoting continuity of care was recognized. Previous studies exploring anticoagulation management in other settings have identified similar themes. Post-discharge management should therefore focus on providing patients with a solid foundation to minimize future problems.

WHAT IS NEW AND CONCLUSION

Addressing the three identified facets of care within a new, collaborative post-discharge warfarin management service may address the perceived deficiencies in existing systems. Improvements may result in the short- and longer-term health outcomes of patients discharged from hospital taking warfarin, including a reduction in their risk of adverse events.

Evaluation and management of chronic pulmonary thromboembolic disease

Pulmonary embolism (PE) is common and the majority of patients survive the acute event. Survivors are at increased risk for adverse outcomes, including persistent thrombi, recurrent embolism, chronic thromboembolic pulmonary hypertension (CTEPH), and death. Anticoagulation protects against recurrence, which has a high mortality rate. The recommended duration of anticoagulation for patients with reversible PE risk factors is 3 months. For patients with idiopathic PE or persistent risk factors, extended duration of anticoagulation is preferred, balanced with an individual patient's risk of hemorrhage, which in itself is a major cause of morbidity and mortality. Among patients with malignancy who develop venous thromboembolism (VTE), low-molecular-weight heparin is preferred over oral vitamin K antagonists in the first 6 months. Thereafter, anticoagulation should be continued indefinitely with either low-molecular-weight heparin or oral vitamin K antagonists. Inferior vena cava filters are not routinely recommended and should only be used in patients who have a contraindication to anticoagulation. Patients who have had VTE and with persistent or recurrent dyspnea should be evaluated for recurrence of VTE or development of CTEPH. Patients with recurrent VTE should be anticoagulated indefinitely. Routine screening for CTEPH in asymptomatic patients is not recommended. Echocardiography often provides the first indication of the presence of pulmonary hypertension. Once presence of CTEPH is established by right-sided heart catheterization and perfusion imaging (ie, ventilation/perfusion scintigraphy, computed tomography angiography, or pulmonary angiography), patients should be referred early to a center with expertise, as it is potentially surgically curable by pulmonary endarterectomy. Those who are deemed inoperable after being evaluated may gain symptomatic benefit from drugs approved for idiopathic pulmonary arterial hypertension. Lung transplantation may also be an option for patients who are not candidates for pulmonary endarterectomy.

Contrast-enhanced CMR in patients after percutaneous closure of the left atrial appendage: a pilot study

BACKGROUND

To evaluate the feasibility and value of first-pass contrast-enhanced dynamic and post-contrast 3D CMR in patients after transcatheter occlusion of left atrial appendage (LAA) to identify incorrect placement and persistent leaks.

METHODS

7 patients with different occluder systems (n = 4 PLAATO; n = 2 Watchman; n = 1 ACP) underwent 2 contrast-enhanced (Gd-DOTA) CMR sequences (2D TrueFISP first-pass perfusion and 3D-TurboFLASH) to assess localization, artifact size and potential leaks of the devices. Perfusion CMR was analyzed visually and semi-quantitatively to identify potential leaks.

RESULTS

All occluders were positioned within the LAA. The ACP occluder presented the most extensive artifact size. Visual assessment revealed a residual perfusion of the LAA apex in 4 cases using first-pass perfusion and 3D-TurboFLASH indicating a suboptimal LAA occlusion.By assessing signal-to-time-curves the cases with a visually detected leak showed a 9-fold higher signal-peak in the LAA apex (567 ± 120% increase from baseline signal) than those without a leak (61 ± 22%; p < 0.03). In contrast, the signal increase in LAA proximal to the occluder showed no difference (leak 481 ± 201% vs. no leak 478 ± 125%; p = 0.48).

CONCLUSION

This CMR pilot study provides valuable non-invasive information in patients after transcatheter occlusion of the LAA to identify correct placement and potential leaks. We recommend incorporating CMR in future clinical studies to evaluate new device types.

The practical management of intracerebral hemorrhage associated with oral anticoagulant therapy

Oral anticoagulant-associated intracerebral hemorrhage is increasing in incidence and is the most feared complication of therapy with vitamin K1 antagonists. Anticoagulant-associated intracerebral hemorrhage has a high risk of ongoing bleeding, death, or disability. The most important aspect of clinical management of anticoagulant-associated intracerebral hemorrhage is represented by urgent reversal of coagulopathy, decreasing as quickly as possible the international normalized ratio to values ≤1·4, preferably ≤1·2, together with life support and surgical therapy, when indicated. Protocols for anticoagulant-associated intracerebral hemorrhage emphasize the immediate discontinuation of anticoagulant medication and the immediate intravenous administration of vitamin K1 (mean dose: 10-20 mg), and the use of prothrombin complex concentrates (variable doses calculated estimate circulating functional prothrombin complex) or fresh-frozen plasma (15-30 ml/kg) or recombinant activated factor VII (15-120 μg/kg). Because of cost and availability, there is limited randomized evidence comparing different reversal strategies that support a specific treatment regimen. In this paper, we emphasize the growing importance of anticoagulant-associated intracerebral hemorrhage and describe options for acute coagulopathy reversal in this setting. Additionally, emphasis is placed on understanding current consensus-based guidelines for coagulopathy reversal and the challenges of determining best evidence for these treatments. On the basis of the available knowledge, inappropriate adherence to current consensus-based guidelines for coagulopathy reversal may expose the physician to medico-legal implications.

Management of massive and submassive pulmonary embolism, iliofemoral deep vein thrombosis, and chronic thromboembolic pulmonary hypertension: a scientific statement from the American Heart Association

Venous thromboembolism (VTE) is responsible for the hospitalization of >250 000 Americans annually and represents a significant risk for morbidity and mortality. Despite the publication of evidence-based clinical practice guidelines to aid in the management of VTE in its acute and chronic forms, the clinician is frequently confronted with manifestations of VTE for which data are sparse and optimal management is unclear. In particular, the optimal use of advanced therapies for acute VTE, including thrombolysis and catheter-based therapies, remains uncertain. This report addresses the management of massive and submassive pulmonary embolism (PE), iliofemoral deep vein thrombosis (IFDVT),and chronic thromboembolic pulmonary hypertension (CTEPH). The goal is to provide practical advice to enable the busy clinician to optimize the management of patients with these severe manifestations of VTE. Although this document makes recommendations for management, optimal medical decisions must incorporate other factors, including patient wishes, quality of life, and life expectancy based on age and comorbidities. The appropriateness of these recommendations for a specific patient may vary depending on these factors and will be best judged by the bedside clinician.

Spontaneous intracerebral haemorrhage: a clinical review

This article provides a clinical overview of spontaneous intracerebral haemorrhage, focusing on clinical aspects of the aetiology, diagnosis and management (both in the emergency department and in a critical care environment) of this important and devastating condition.

Clinical Outcomes of a Collaborative, Home-Based Postdischarge Warfarin Management Service

Background:

Warfarin remains a high-risk drug for adverse events, especially following discharge from the hospital. New approaches are needed to minimize the potential for adverse outcomes during this period.

Objective:

To evaluate the clinical outcomes of a collaborative, home-based postdischarge warfarin management service adapted from the Australian Home Medicines Review (HMR) program.

Methods:

In a prospective, nonrandomized controlled cohort study, patients discharged from the hospital and newly initiated on or continuing warfarin therapy received either usual care (UC) or a postdischarge service (PDS) of 2 or 3 home visits by a trained, HMR-accredited pharmacist in their first 8 to 10 days postdischarge. The PDS involved point-of-care international normalized ratio (INR) monitoring, warfarin education, and an HMR, in collaboration with the patient's general practitioner and community pharmacist. The primary outcome measure was the combined incidence of major and minor hemorrhagic events in the 90 days postdischarge. Secondary outcome measures included the incidences of thrombotic events, combined hemorrhagic and thombotic events, unplanned and warfarin-related hospital readmissions, death, INR control, and persistence with therapy al 8 and 90 days postdischarge.

Results:

The PDS (n = 129) was associated with statistically significantly decreased rates of combined major and minor hemorrhagic events to day 90 (5.3% vs 14.7%; p = 0.03) and day 8 (0.9% vs 7.2%; p = 0.01) compared with UC (n = 139). The rate of combined hemorrhagic and thrombotic events to day 90 also decreased (6.4% vs 19.0%; p = 0.008) and persistence with warfarin therapy improved (95.4% vs 83.6%; p = 0.004). No significant differences in readmission and death rates or INR control were demonstrated.

Conclusions:

This study demonstrated the ability of appropriately trained accredited pharmacists working within the Australian HMR framework to reduce adverse events and improve persistence In patients taking warfarin following hospital discharge. Widespread implementation of such a service has the potential to enhance medication safety along the continuum of care. KEY WORDS: adverse drug events, community pharmacy services, international normalized ratio, patient discharge, warfarin.

Epidemiology of the association between anticoagulants and intraocular hemorrhage in patients with neovascular age-related macular degeneration

PURPOSE

To determine the cumulative incidence and annual incidence of intraocular hemorrhage (subretinal hemorrhage or vitreous hemorrhage) in patients with neovascular age-related macular degeneration (AMD) and association with daily antiplatelet or anticoagulant (AP/AC) medication usage (aspirin, clopidogrel, and warfarin), age, gender, hypertension, diabetes mellitus, or bilateral neovascular AMD.

METHODS

Retrospective cross-sectional study in a tertiary university setting. Data on 195 eyes of 195 patients without previous intraocular hemorrhage examined over 73 months were reviewed.

RESULTS

Ninety-six of 195 patients (49.2%) were taking daily AP/ACs. Of patients taking daily AP/AC agents, 63.5% had hemorrhage compared with 29.2% of patients not taking (odds ratio = 4.21; 95% confidence interval = 1.42-8.46; P < 0.001). The overall annual incidence of intraocular hemorrhage was 0.14% per year. Among patients taking daily AP/AC, the cumulative incidence (61 of 96, 63.5%) and annual incidence (0.10%) of concurrent intraocular hemorrhage were significantly greater compared with patients not taking them (29 of 99, 29.2% and 0.04%, respectively; P < 0.0001). Fourteen of 18 patients (77%) taking more than 1 daily AP/AC had occurrence of intraocular hemorrhage. Antiplatelet or anticoagulant usage was an independent risk factor for the development of intraocular hemorrhage. The use of any agent resulted in a significantly increased risk of developing intraocular hemorrhage. Additionally, presence of bilateral neovascular AMD was a significant association in those taking daily AP/ACs, whereas age was a significant association in those not taking daily AP/AC agents.

CONCLUSION

All three daily AP/AC types were significantly associated with an increased risk of the development intraocular hemorrhage in patients with neovascular AMD, whereas gender, hypertension, and diabetes were not. Age was not significantly associated with hemorrhage in patients taking daily AP/AC agents, whereas the presence of bilateral neovascular AMD was significantly associated with hemorrhage. These findings indicate that the AP/AC use may predispose patients with neovascular AMD to intraocular hemorrhage more so than age and duration of disease alone. While the risk that discontinuing these medicines would pose to the patients' health may be too great to justify, ensuring that an appropriate medication dosage is maintained should be a priority within this patient population.

A role for pharmacists in community-based post-discharge warfarin management: protocol for the 'the role of community pharmacy in post hospital management of patients initiated on warfarin' study

BACKGROUND

Shorter periods of hospitalisation and increasing warfarin use have placed stress on community-based healthcare services to care for patients taking warfarin after hospital discharge, a high-risk period for these patients. A previous randomised controlled trial demonstrated that a post-discharge service of 4 home visits and point-of-care (POC) International Normalised Ratio (INR) testing by a trained pharmacist improved patients' outcomes. The current study aims to modify this previously trialled service model to implement and then evaluate a sustainable program to enable the smooth transition of patients taking warfarin from the hospital to community setting.

METHODS/DESIGN

The service will be trialled in 8 sites across 3 Australian states using a prospective, controlled cohort study design. Patients discharged from hospital taking warfarin will receive 2 or 3 home visits by a trained 'home medicines review (HMR)-accredited' pharmacist in their 8 to 10 days after hospital discharge. Visits will involve a HMR, comprehensive warfarin education, and POC INR monitoring in collaboration with patients' general practitioners (GPs) and community pharmacists. Patient outcomes will be compared to those in a control, or 'usual care', group. The primary outcome measure will be the proportion of patients experiencing a major bleeding event in the 90 days after discharge. Secondary outcome measures will include combined major bleeding and thromboembolic events, death, cessation of warfarin therapy, INR control at 8 days post-discharge and unplanned hospital readmissions from any cause. Stakeholder satisfaction will be assessed using structured postal questionnaire mailed to patients, GPs, community pharmacists and accredited pharmacists at the completion of their study involvement.

DISCUSSION

This study design incorporates several aspects of prior interventions that have been demonstrated to improve warfarin management, including POC INR testing, warfarin education and home visits by trained pharmacists. It faces several potential challenges, including the tight timeframe for patient follow-up in the post-discharge period. Its strengths lie in a strong multidisciplinary team and the utilisation of existing healthcare frameworks. It is hoped that this study will provide the evidence to support the national roll-out of the program as a new Australian professional community pharmacy service.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry Number 12608000334303.

Emerging clinical applications in cardiovascular pharmacogenomics

Over one-fourth of the 36 million annual outpatient prescriptions filled in the United States are known to have human genomic biomarker information available that predicts drug safety and efficacy, or both. However, to date, we have not systematically implemented strategies to effectively use this data in clinical practice to improve patient outcomes. Part of the difficulty has stemmed from the only modest predictive capacity of previously identified gene variants, lack of replication of data in multiple studies, and the hesitancy of the clinical community to translate data gleaned from basic and translational research to routine clinical practice. Now, additional key variants that strongly impact drug absorption, metabolism, and excretion are rapidly surfacing through the use of genome-wide association technology. Most importantly, these variants are being validated in independent cohorts of thousands of cases and controls. In the near future, the dramatic reduction in the cost of DNA sequencing will lead to further insight into the common and rare genetic variants that strongly predict our individual response to commonly used medications. The clinical community will need to be prepared to utilize this vital data in aiding their selection of the right drug for the right patient if we expect to significantly reduce the ever increasing burden of societies' most common diseases. Herein, we detail the most clinically compelling and robust examples of pharmacogenomics emerging in the field of cardiovascular disease and hopefully foretell how cardiovascular disease might be treated in the era of genomic medicine.

Determination of plasma warfarin concentrations in Korean patients and its potential for clinical application

BACKGROUND

Warfarin is a widely used oral anticoagulant with broad within- and between-individual dose requirements. Warfarin concentrations can be monitored by assessing its pharmacologic effects on International Normalized Ratio (INR). However, this approach has not been applied in the routine clinical management of patients receiving warfarin therapy. We performed a plasma warfarin assay using high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) to determine if such an assay can be utilized in routine clinical practice.

METHODS

We included a total of 105 patients with atrial fibrillation, and who were receiving warfarin for more than 1 yr. The plasma concentrations of total warfarin and 7-hydroxywarfarin were determined by HPLC-MS/MS (Waters, UK). We assessed the association between warfarin dose, concentration, and INR as well as the effects of these factors on warfarin concentrations.

RESULTS

The mean maintenance dose of warfarin in 105 patients was 4.1 +/-1.3 mg/day (range, 1.7-8.0 mg/day) and their mean plasma warfarin concentration was 1.3+/-0.5 mg/L. We defined a concentration range of 0.6-2.6 mg/L (corresponding to the 2.5th to 97.5th percentile range of the Plasma warfarin levels in the 74 patients showing INR within target range) as the therapeutic range for warfarin. The correlation of warfarin dose with warfarin concentration (r(2)=0.259, P<0.001) was higher than that with INR (r(2)=0.029, P=0.072).

CONCLUSIONS

There was a significant correlation between warfarin dose and plasma warfarin concentrations in Korean patients with atrial fibrillation. Hence, plasma warfarin monitoring can help determine dose adjustments and improve our understanding of individual patient response to warfarin treatment.

Regional anesthesia in the patient receiving antithrombotic or thrombolytic therapy: American Society of Regional Anesthesia and Pain Medicine Evidence-Based Guidelines (Third Edition)

The actual incidence of neurologic dysfunction resulting from hemorrhagic complications associated with neuraxial blockade is unknown. Although the incidence cited in the literature is estimated to be less than 1 in 150,000 epidural and less than 1 in 220,000 spinal anesthetics, recent epidemiologic surveys suggest that the frequency is increasing and may be as high as 1 in 3000 in some patient populations.Overall, the risk of clinically significant bleeding increase with age,associated abnormalities of the spinal cord or vertebral column, the presence of an underlying coagulopathy, difficulty during needle placement,and an indwelling neuraxial catheter during sustained anticoagulation( particularly with standard heparin or low-molecular weight heparin). The need for prompt diagnosis and intervention to optimize neurologic outcome is also consistently reported. In response to these patient safety issues, the American Society of Regional Anesthesia and Pain Medicine (ASRA) convened its Third Consensus Conference on Regional Anesthesia and Anticoagulation. Practice guidelines or recommendations summarize evidence-based reviews. However, the rarity of spinal hematoma defies a prospective randomized study, and there is no current laboratory model. As a result,the ASRA consensus statements represent the collective experience of recognized experts in the field of neuraxial anesthesia and anticoagulation. These are based on case reports, clinical series, pharmacology,hematology, and risk factors for surgical bleeding. An understanding of the complexity of this issue is essential to patient management.

COU254, a specific 3-carboxamide-coumarin inhibitor of coagulation factor XII, does not protect mice from acute ischemic stroke

Background

Anticoagulation is an important means to prevent from acute ischemic stroke but is associated with a significant risk of severe hemorrhages. Previous studies have shown that blood coagulation factor XII (FXII)-deficient mice are protected from pathological thrombus formation during cerebral ischemia without bearing an increased bleeding tendency. Hence, pharmacological blockade of FXII might be a promising and safe approach to prevent acute ischemic stroke and possibly other thromboembolic disorders but pharmacological inhibitors selective over FXII are still lacking. In the present study we investigated the efficacy of COU254, a novel nonpeptidic 3-carboxamide-coumarin that selectively blocks FXII activity, on stroke development and post stroke functional outcome in mice.

Methods

C57Bl/6 mice were treated with COU254 (40 mg/kg i.p.) or vehicle and subjected to 60 min transient middle cerebral artery occlusion (tMCAO) using the intraluminal filament method. After 24 h infarct volumes were determined from 2,3,5-Triphenyltetrazoliumchloride(TTC)-stained brain sections and functional scores were assessed. Hematoxylin and eosin (H&E) staining was used to estimate the extent of neuronal cell damage. Thrombus formation within the infarcted brain areas was analyzed by immunoblot.

Results

Infarct volumes and functional outcomes on day 1 after tMCAO did not significantly differ between COU254 pre-treated mice or untreated controls (p > 0.05). Histology revealed extensive ischemic neuronal damage regularly including the cortex and the basal ganglia in both groups. COU254 treatment did not prevent intracerebral fibrin(ogen) formation.

Conclusions

COU254 at the given concentration of 40 mg/kg failed to demonstrate efficacy in acute ischemic stroke in this preliminary study. Further preclinical evaluation of 3-carboxamide-coumarins is needed before the antithrombotic potential of this novel class of FXII inhibitors can be finally judged.

Subretinal hemorrhages associated with age-related macular degeneration in patients receiving anticoagulation or antiplatelet therapy

PURPOSE

To evaluate the incidence of and risk factors for subretinal hemorrhages in age-related macular degeneration (AMD) patients on anticoagulation or antiplatelet therapy.

DESIGN

Retrospective, observational case series.

METHODS

We retrospectively reviewed the medical and photographic records of 71 consecutive patients who sought treatment at our institution with acute subretinal hemorrhages complicating age-related macular degeneration. The size of the subretinal hemorrhage was measured in standardized Macular Photocoagulation Study disc areas. Data on the use of medications and medical indications for anticoagulation and antiplatelet therapy were obtained.

RESULTS

Overall, patients receiving antithrombotic therapy had a significantly larger subretinal hemorrhage size (mean, 9.71 disc areas) than patients not receiving anticoagulant or antiplatelet therapy (mean, 2.99 disc areas). Subgroup analysis revealed that both antiplatelet (P < .0001) and anticoagulant therapy (P = .003) were associated with a significantly larger bleeding size. Moreover, subgroup analysis among patients with arterial hypertension revealed that individuals receiving antithrombotic therapy had a statistically significantly larger hemorrhage size than hypertensive patients who did not receive anticoagulants or antiplatelet agents (P < .0001).

CONCLUSIONS

Our results indicate that anticoagulants and antiplatelet agents are strongly associated with the development of large subretinal hemorrhages in AMD patients. Moreover, arterial hypertension is a strong risk factor for large subretinal hemorrhages in AMD patients receiving anticoagulants or antiplatelet agents. Physicians should be aware of an increased risk of extensive subretinal hemorrhage in AMD patients when deciding on the initiation and duration of anticoagulant and antiplatelet therapy.