Anticoagulants in older patients. A safety perspective

Hemorrhagic Coagulation Disorders and Ischemic Stroke: How to Reconcile Both?

Coagulation and fibrinolytic system disorders are conditions in which the blood's ability to clot is impaired, resulting in an increased risk of thrombosis or bleeding. Although these disorders are the expression of two opposing tendencies, they can often be associated with or be a consequence of each other, contributing to making the prognosis of acute cerebrovascular events more difficult. It is important to recognize those conditions that are characterized by dual alterations in the coagulation and fibrinolytic systems to reduce the prognostic impact of clinical conditions with difficult treatment and often unfortunate outcomes. Management of these individuals can be challenging, as clinicians must balance the need to prevent bleeding episodes with the potential risk of clot formation. Treatment decisions should be made on an individual basis, considering the specific bleeding disorder, its severity, and the patient's general medical condition. This review aims to deal with all those forms in which coagulation and fibrinolysis represent two sides of the same media in the correct management of patients with acute neurological syndrome. Precision medicine, personalized treatment, advanced anticoagulant strategies, and innovations in bleeding control represent future directions in the management of these complex pathologies in which stroke can be the evolution of two different acute events or be the first manifestation of an occult or unknown underlying pathology.

Effect of combination of prophylactic or therapeutic anticoagulation with aspirin on the outcomes of hospitalized COVID-19 patients: An observational retrospective study

Regimens for managing thromboembolic complications of COVID-19 are still not very well established. The present study compares the clinical characteristics and outcomes of patients hospitalized with COVID-19 receiving different anticoagulation regimens with and without aspirin. This is a retrospective observational study of 491 patients hospitalized for COVID-19 from August 2020 to April 2021. Data regarding clinical characteristics, laboratory findings, and outcomes of patients receiving different anticoagulation with and without aspirin regimens was collected, according to which 5 patient groups were defined: received no anticoagulation (NAA), prophylactic anticoagulation with (PA) or without aspirin (PAA) and therapeutic anticoagulation with (TA) or without aspirin (TAA). The average age was highest in the TAA group. Desaturation was highest in the TA and TAA groups. Diabetes, hypertension, dyslipidemia and coronary artery disease were the most prevalent in aspirin groups (PAA and TAA) as was heart failure in the TA and TAA groups and cancer in the TA and PAA groups. Elevated troponin was observed in the PAA and TAA groups. TA and TAA patients received oxygen therapy, needed ICU admission overall, and required invasive ventilation and vasopressors the most. Prophylactic anticoagulation groups (PA and PAA) had the highest patient survival rates. Patients with severe COVID-19 infections were more likely to receive higher, therapeutic, anticoagulation doses. Aspirin was given to patients with preexisting comorbidities, but it had no statistically significant impact on the outcomes of the different groups. Groups receiving prophylactic anticoagulation had the best survival outcomes.

Acquired Hemophilia A Masquerading as Bleeding on Anticoagulation: A Case Report Including Key Laboratory Considerations

We report a case of a patient with recurrent hematomas while on anticoagulation for a pulmonary embolism and a prolonged hospital stay due to a delayed diagnosis for acquired hemophilia A. Acquired hemophilia A is a rare autoimmune bleeding disorder with autoantibodies directed against coagulation factor VIII (FVIII), leading to an acquired FVIII deficiency. A prolonged isolated activated partial thromboplastin time (aPTT) in a bleeding patient warrants workup for acquired hemophilia A. This is specifically challenging in patients with thrombosis on anticoagulation and can lead to significant delays in diagnosis and associated morbidities. The case highlights the need for further awareness of this disease, potential laboratory pitfalls when conducting and interpreting coagulation assays, and the management considerations in a patient with a simultaneous thrombotic and hemorrhagic condition.

Coagulation Status and Surgical Approach as Predictors of Postoperative Anemia in Patients Undergoing Thoracic Surgery: A Retrospective Study

Objective: Postoperative anemia is a common complication after a major surgery. Our study aims to identify factors that are associated with higher risk of developing postoperative anemia after thoracic surgery.

Methods: We conducted a retrospective study of 465 patients who underwent pulmonary surgery in 2017 in Shanghai Pulmonary Hospital, China. Of them, 191 patients underwent standard open thoracotomy (OT), and 274 patients underwent video-assisted thoracic surgery (VATS). A total of 350 patients were diagnosed with postoperative anemia, and 115 patients did not have anemia. Multiple logistic regression was used to compute odds ratios for predicting preoperative anemia.

Results: Postoperative anemia was associated with significantly lower weight (p < 0.001) and height (p = 0.022) of the patients, as well as higher prothrombin time (PT), and international normalized ratio (INR) (p = 0.012). Open thoracotomy resulted in a 1.2-fold increase in the incidence of postoperative anemia compared to VATS (p = 0.002). Multiple logistic regression analysis identified INR [OR (95% CI) 24.46 (2.05–292.27; p = 0.012] and surgical approach [OR (95% CI) 0.48 (0.31–0.74); p < 0.001] as predictors of postoperative anemia and postoperative drop in hemoglobin (Hb).

Conclusion: Postoperative coagulation status and surgical approach are statistically significant predictors of postoperative anemia in patients undergoing thoracic surgery. International normalized ratio and surgical approach are specifically associated with Hb drop immediately after the surgery.

Spontaneous massive pectoral hematoma induced by vitamin K antagonist therapy: a case report

Vitamin K antagonists (VKA) based oral anticoagulation, is widely used for the prevention and treatment of thromboembolic disease. The major complication of this therapy is bleeding, and sometimes it can occur in unsuspected areas. Spontaneous pectoral hematoma is one of the rare complications due to over anticoagulation by VKA therapy, with only a few cases reported in the literature. Concomitant use of this therapy with commonly used antibiotic, especially in the elderly with multiple comorbidities, can increase the risk of bleeding. Herein, we report a case of a 72-year-old woman under VKA for the treatment of atrial fibrillation, who presented with a spontaneous massive pectoral hematoma, while using antibiotic to treat a respiratory tract infection, who was successfully managed.

Updated Outpatient Cardiac Rehabilitation Delivery Formats Tailored to the Iranian Population

This article is a Letter to Editor and does not include an Abstract.

Warfarin-Induced Spontaneous Bilateral Breast and Extrathoracic Hematoma in an Elderly Woman

Warfarin- induced spontaneous breast hematoma is a very rare disease, with only a few cases having been reported in the literature so far. We describe an 80-year-old woman who had warfarin therapy due to deep vein thrombosis in a lower extremity. The patient was admitted with a history of swelling and red area on her bilateral breasts, chest wall, right arm, and right flank. She was treated conservatively with success. She was discharged after about 3 weeks without complications and was well at 6 months’ follow-up.

Risk factors for severe bleeding events during warfarin treatment: the influence of sex, age, comorbidity and co-medication

PURPOSE

To investigate risk factors for severe bleeding during warfarin treatment, including the influence of sex, age, comorbidity and co-medication on bleeding risk.

METHODS

Patients initiating warfarin treatment between 2007 and 2011 were identified in the nationwide Swedish Prescribed Drug Register, and diagnoses of severe bleeding were retrieved from the National Patient Register. Hazard ratios (HR) with 95% confidence intervals (CI) for severe bleeding were estimated using multiple Cox regression adjusting for indications and including covariates age, sex, comorbidities and co-medications. Interactions between sex and other covariates were investigated.

RESULTS

The study cohort included 232,624 patients ≥ 18 years (101,011 women and 131,613 men). The incidence rate of severe bleeding was 37 per 1000 person-years, lower among women than men with an adjusted HR (95% CI) of 0.84 (0.80-0.88). Incidence of bleeding increased with age, HR 2.88 (2.37-3.50) comparing age ≥ 80 to < 40 years, and comorbidities associated with the highest risk of severe bleeding were prior bleeding, HR 1.85 (1.74-1.97); renal failure, HR 1.82 (1.66-2.00); and alcohol dependency diagnosis, HR 1.79 (1.57-2.05). Other comorbidities significantly associated with bleeding events were hypertension, diabetes, peripheral vascular disease, congestive heart failure, liver failure, stroke/TIA, COPD and cancer.

CONCLUSION

Most of the well-established risk factors were found to be significantly associated with bleeding events in our study. We additionally found that women had a lower incidence of bleeding. Potential biases are selection effects, residual confounding and unmeasured frailty.

Evaluation of Anticoagulation Therapy in an Academic Nursing Home

Objective:

To evaluate the warfarin management patterns in an academic nursing home and evaluate what predetermined factors are associated with variability in the international normalized ratio (INR).

Setting:

A 566-bed academic nursing home.

Methods:

A retrospective chart review of all residents receiving warfarin therapy for >3 consecutive months in a calendar year was conducted. Data were collected regarding the number of times the INR fluctuated during the follow-up period and the degree of fluctuation between each blood sampling. An INR that changed by 0.5–0.99 between samplings was classified as a small fluctuation; a change >0.99 was defined as a large fluctuation. The sample was divided into 2 groups, easy management and difficult management, based on variability in the INR. The easy-management group consisted of residents who had small fluctuations in the INR and who had INRs outside of the therapeutic range ≤10% of the time. The difficult- management group had large fluctuations in the INR, with the ratio outside of the therapeutic range >10% of the time.

Results:

Thirty-seven patients were taking warfarin (mean ± SD age 71 ± 14 y; mean number of medical illnesses 7.6 ± 3). The mean length of time of warfarin therapy was 10.6 ± 3.2 months. The average dose and INR were 4.0 ± 1.9 mg and 2.0 ± 0.3, respectively. No statistically significant differences were found between age, dose, or INR. For patients who had INR values exceeding the therapeutic range, there was no significant difference between the management groups in length of treatment, age, number of medical illnesses, number of high-risk factors, dose, average monthly INR, number of medication adjustments per year, albumin and creatinine levels, total number of medications, or number of routine medications known to interact with warfarin. The difficult-management group received more medications known to interact with warfarin than the easy-management group. These medications may have caused the INR to increase above the normal range (p = 0.003), as well as producing a large (p = 0.001) or small fluctuation (p = 0.0007) in the INR. Of all the interacting medications, 55% were antibiotics and 28% were analgesics. No statistically significant differences in outcome were seen between groups.

Conclusions:

Results of this study indicate that large variations (>0.99) in the INR may be due to newly prescribed medications that enhance the anticoagulant effect of warfarin. These variations may be minimized by closely monitoring the INR when a drug known to interact with warfarin is prescribed.

An automated database case definition for serious bleeding related to oral anticoagulant use

PURPOSE

Bleeding complications are a serious adverse effect of medications that prevent abnormal blood clotting. To facilitate epidemiologic investigations of bleeding complications, we developed and validated an automated database case definition for bleeding-related hospitalizations.

METHODS

The case definition utilized information from an in-progress retrospective cohort study of warfarin-related bleeding in Tennessee Medicaid enrollees 30 years of age or older. It identified inpatient stays during the study period of January 1990 to December 2005 with diagnoses and/or procedures that indicated a current episode of bleeding. The definition was validated by medical record review for a sample of 236 hospitalizations.

RESULTS

We reviewed 186 hospitalizations that had medical records with sufficient information for adjudication. Of these, 165 (89%, 95%CI: 83-92%) were clinically confirmed bleeding-related hospitalizations. An additional 19 hospitalizations (10%, 7-15%) were adjudicated as possibly bleeding-related. Of the 165 clinically confirmed bleeding-related hospitalizations, the automated database and clinical definitions had concordant anatomical sites (gastrointestinal, cerebral, genitourinary, other) for 163 (99%, 96-100%). For those hospitalizations with sufficient information to distinguish between upper/lower gastrointestinal bleeding, the concordance was 89% (76-96%) for upper gastrointestinal sites and 91% (77-97%) for lower gastrointestinal sites.

CONCLUSION

A case definition for bleeding-related hospitalizations suitable for automated databases had a positive predictive value of between 89% and 99% and could distinguish specific bleeding sites.

Warfarin use associates with increased risk for stroke in hemodialysis patients with atrial fibrillation

Use of warfarin, clopidogrel, or aspirin associates with mortality among patients with ESRD, but the risk-benefit ratio may depend on underlying comorbidities. Here, we investigated the association between these medications and new stroke, mortality, and hospitalization in a retrospective cohort analysis of 1671 incident hemodialysis patients with preexisting atrial fibrillation. We followed patient outcomes from the time of initiation of dialysis for an average of 1.6 yr. Compared with nonuse, warfarin use associated with a significantly increased risk for new stroke (hazard ratio 1.93; 95% confidence interval 1.29 to 2.90); clopidogrel or aspirin use did not associate with increased risk for new stroke. Analysis using international normalized ratio (INR) suggested a dose-response relationship between the degree of anticoagulation and new stroke in patients on warfarin (P = 0.02 for trend). Warfarin users who received no INR monitoring in the first 90 d of dialysis had the highest risk for stroke compared with nonusers (hazard ratio 2.79; 95% confidence interval 1.65 to 4.70). Warfarin use did not associate with statistically significant increases in all-cause mortality or hospitalization. In conclusion, warfarin use among patients with both ESRD and atrial fibrillation associates with an increased risk for stroke. The risk is greatest in warfarin users who do not receive in-facility INR monitoring.

Secondary stroke prevention strategies for the oldest patients: possibilities and challenges

Older adults are not only at higher risk of experiencing stroke, but also have multiple co-morbidities that make treatment for secondary stroke prevention challenging. Very few clinical trials specifically related to secondary stroke prevention treatment efficacy have focused on the oldest-old (>or=85 years) and, therefore, evidence-based recommendations for treatment specific to this population are not available. Some of the special considerations for stroke prevention treatments in older patients include careful titration of blood-pressure-lowering drugs to avoid hypotension, the risk of haemorrhagic stroke with HMG-CoA reductase inhibitors (statins) and weighing the risk of recurrent ischaemia versus bleeding in patients taking antiplatelet or anticoagulant therapy. The risk of peri-procedural complications appears to be high with both carotid angioplasty and stenting and carotid endarterectomy in older patients with carotid stenosis. Other common issues in older patients include adverse drug events, recognizing the risk of dementia, depression and osteoporosis and deciding when to discontinue secondary stroke prevention. In this review, we provide the practitioner with the evidence related to specific approaches to secondary stroke prevention in older patients, and identify the knowledge gaps that currently limit our ability to appropriately treat this vulnerable population.

Primary Prevention of Venous Thromboembolism in Long-Term Care: Identifying and Managing the Risk

Venous thromboembolism (VTE) is a significant, but underestimated, cause of morbidity and mortality in long-term care settings. VTE risk increases significantly with age and is further increased by comorbidities common to this group; however, advancing age and limited mobility alone are insufficient to warrant pharmacological prophylaxis. Recognizing those at increased VTE risk during an acute illness is crucial for appropriate and timely prophylaxis. Warfarin is used for the long-term secondary prevention of VTE, whereas unfractionated and low-molecular-weight heparins are used for primary prophylaxis. The elderly are at increased risk for bleeding complications, because of the high frequency of comorbidities and comedications. Attention to dosing is recommended for those with severely impaired renal function, low body weight, or perceived to be at high bleeding risk. This review addresses the role of risk assessment in the decision of when to provide prophylaxis to an individual in long-term care and highlights key management issues for those prescribed prophylaxis.

Bleeding complications during warfarin treatment in primary healthcare centres compared with anticoagulation clinics

OBJECTIVES

To examine determinants of bleeding complications during warfarin treatment in an unselected patient population and evaluate possible differences in safety between specialized anticoagulation clinics and primary healthcare centres.

DESIGN

Prospective cohort study. Data were collected with an admission form and medical records were scrutinized in order to pursue all adverse events. Differences between groups were estimated with a t-test and chi-squared test, and univariate and multivariate Cox regression analysis.

SETTING

All patients treated and monitored with oral anticoagulation in primary healthcare centres and specialized anticoagulation clinics in the Sundsvall and Skellefteå region (northern Sweden) during a five-year period.

SUBJECTS

A total of 2731 patients corresponding to 5044 treatment years.

MAIN OUTCOME MEASURES

Bleedings were classified as fatal or major. Major bleedings were defined as an event causing admission, prolonged in-hospital care or death.

RESULTS

In total 195 major bleedings occurred corresponding to 3.9% per treatment year, including 34 fatal events (0.67% per treatment year). Patients monitored at the two specialized anticoagulation clinics combined had a major bleeding frequency of 4.1% as compared with 3.9% at primary healthcare units. The frequency of fatal haemorrhage was 0.57% and 0.76%, respectively. The rate of major and fatal bleeding was age related with an increase of 4% and 5%, respectively, per year.

CONCLUSIONS

There was no difference in bleeding complications between patients monitored at primary healthcare centres and specialized anticoagulation clinics. Age was continuously and independently associated with bleeding risk. These study data indicate the need to exercise caution in treatment of the elderly.

Management of venous thromboembolism in the elderly

In this review the authors discuss the use of oral and parenteral anticoagulants for the prevention and treatment of venous thromboembolism (VTE) in the elderly. The use of anticoagulant agents in VTE prophylaxis and treatment in the elderly is complicated by an increase with age in the presence of multiple risk factors and co-morbidities that may increase the risk of both VTE and bleeding. Age itself is identified as an independent risk factor for thromboembolism. VTE is underdiagnosed in the elderly population, and routine prophylaxis frequently falls short of the levels required according to level of risk. Although appropriate anticoagulation of at-risk patients offers a means of reducing the significant VTE burden in this population, concerns have been raised over the use of anticoagulants in a patient group in whom multiple risk factors are common. Bleeding in the elderly can be exacerbated by reduced renal clearance and hypersensitivity to oral anticoagulants that may lead to over-anticoagulation. Although bleeding due to anticoagulant therapy is a serious issue in the elderly, it is often overemphasized, given the therapeutic value otherwise observed in treating this patient group. Warfarin is still used in VTE prophylaxis after orthopaedic surgery and for long-term VTE treatment. Unfractionated and low-molecular-weight heparins (LMWHs) have been shown to be safe and effective in the prophylaxis of VTE, and are now being shown to be as effective as warfarin in the initial and long-term treatment of VTE. LMWHs confer the advantage over unfractionated heparin of subcutaneous once-daily administration with no requirement for laboratory monitoring of their anticoagulant effect, which allows for the convenience of outpatient therapy. New anticoagulants that may be of potential benefit in this patient population include fondaparinux sodium, but clinical experience of this drug in the elderly remains limited.

Oral anticoagulant treatment: risk factors involved in 500 intracranial hemorrhages

Intracranial bleeding is the most severe complication caused by anticoagulant or antiplatelet treatment. The increasing use of this therapy, especially in older people, makes the balance between clinical benefit and bleeding risk an important consideration. A retrospective study of all consecutive 500 intracranial hemorrhages in the West Valladolid area, approximately 220,000 people, during the period 1998 to 2004, was performed. In relation to mortality, predisposing conditions were included, such as age, antithrombotic treatment, arterial hypertension, cancer, blood diseases, vascular malformations, and traumatisms. The incidence of intracranial hemorrhage was 310 per 100,000 per year with a mortality of 30%. Higher mortality was found in antiplatelet-treated patients (44.9%) than in anticoagulated patients (31.1%). This may be related to a different mean age of 78 vs. 71 years. Arterial hypertension was the most frequent risk factor (45.1% in nontreated patients, 60% anticoagulated, and 75.5% antiplatelet). The relative risk of intracranial bleeding in anticoagulated patients was 11.2 (p < 0.001) with an incidence of 0.03% and a median of 14 months since treatment began. The median INR was 3.3. In 40% of the patients the previous five controls were in range. Strict consideration of indications criteria joined to a better control of risk factors may avoid intracranial bleeding episodes.

Safety and low molecular weight heparin in older people in a hospital with ambulatory care

To examine major bleeding and mortality rates of low molecular weight heparin (LMWH) and unfractionated heparin (UFH) for patients with pulmonary embolism (PE) and/or deep vein thrombosis (DVT), a retrospective review of the medical records for 286 patients who presented at a local hospital with PE and/or DVT during the period November 2002-August 2003 was performed.

DATA COLLECTED

presence of co-morbidities, concurrent medications, presence, site and severity of bleeding, outcome. Of all the patients, 50.7% received LMWH plus warfarin, 21.0% received UFH plus LMWH plus warfarin, 14.0% received UFH and warfarin, and 9.8% received LMWH only. There were nine minor bleeds and six major bleeds, which resulted in four deaths. Being a hospitalized patient and being age > or =70 years were associated with a major bleed (p<0.05). For hospital inpatients age > or =70 years on UFH and LMWH the number of major bleeds/1000 patient days was 18.9 and 9.2, respectively. The major bleeding rate is comparable if not better than that reported in the literature in our hospital setting where nearly half of the anticoagulation services were provided as ambulatory care. The increased rate of bleeding in the elderly we found is consistent with the findings of previous studies.

Anticoagulant Treatment of Deep Vein Thrombosis and Pulmonary Embolism

Venous thrombosis is a common disease. As the mean age of the population increases, so does the incidence of venous thromboembolism. Anticoagulant therapy is equally effective in young and older patients, and can reduce substantially the associated morbidity and mortality. When considering long-term oral anticoagulant therapy in older patients, however, careful ongoing evaluation is imperative to ensure that the risk of bleeding does not outweigh the antithrombotic benefits.

Is INR between 2.0 and 3.0 the optimal level for Chinese patients on warfarin therapy for moderate-intensity anticoagulation?

AIM

To examine the optimal range of International Normalized Ratio (INR) for Chinese patients receiving warfarin for moderate-intensity anticoagulation.

METHODS

This was a retrospective cohort study conducted at the ambulatory setting of a 1400-bed public teaching hospital in Hong Kong. The INR measurements and occurrence of serious or life-threatening haemorrhagic and thromboembolic events among patients newly started on warfarin from 1 January 1999 to 30 June 2001 for indications with target INR 2-3 were analysed. The INR-specific incidence of bleeding and thromboembolism were calculated.

RESULTS

A total of 491 patients were included, contributing to 453 patient-years of observation period. Forty-seven of the 491 patients experienced 25 haemorrhagic events (5.5 per 100 patient-years) and 27 thromboembolic events (6.0 per 100 patient-years). The percentage of patient-time spent within therapeutic INR range (2-3), INR <2 and INR >3 were 50, 44 and 6%, respectively. The incidence of either haemorrhagic or thromboembolic events was lowest (< or =4 events per 100 patient-years) at INR values between 1.8 and 2.4.

CONCLUSIONS

An INR of 1.8-2.4 appeared to be associated with the lowest incidence rate of major bleeding or thromboembolic events in a cohort of Hong Kong Chinese patients receiving warfarin therapy for moderate-intensity anticoagulation.

Evaluation à l’occasion de leur hospitalisation de la qualité de l’anticoagulation orale chez des patients traités par antivitamines K

BACKGROUND

Excessive or insufficient anticoagulation therapy and its associated risks are of major concern in patients receiving oral anticoagulants. Such complications can be avoided by more rigorous management.

OBJECTIVE

The aim of our study was to evaluate those patients receiving oral anticoagulant therapy on the day of hospitalisation among all patients admitted to the Amiens University Hospital during 14 days.

METHODS

We evaluated the quality of management of the treatment in these patients, taking into account the international normalised ratio (INR), as well as important parameters such as the summary of the product characteristics (SPCs), drug interactions, and the level of knowledge of anticoagulant treatment by the patients themselves (questionnaire).

RESULTS

Of the 2498 adult patients hospitalised, 86 patients (30 female and 56 male aged between 26 and 95 years [mean 70 years]) treated with oral anticoagulants were evaluated. At admission, seven cases of haemorrhage and two of thrombosis were registered. One drug-related death occurred and one patient had sequelae. In 17.5% of the cases, the prescription was not fully in agreement with the SPCs. This percentage increased to 67% for patients with adverse effects. In 41% of the patients, the INR was outside the therapeutic zone. The dosage regimen was too complex in 11% of cases. Six drug combinations were labelled as not recommended in the SPCs: four with aspirin <3 g/day and two with nonsteroidal anti-inflammatory drugs. The analysis of questionnaires showed that patients had insufficient knowledge of their treatment: only 16 of 66 knew the risks resulting from overdose or an insufficient dose of the anticoagulant drug, 25 of 66 knew that anticoagulation induced by the treatment can be influenced by food, 10 of 66 knew the therapeutic range of the INR appropriate for them, and 8 of 66 knew that intramuscular injections were prohibited.

CONCLUSIONS

These data confirm that anticoagulant treatment needs to be more strictly controlled in order to avoid adverse effects. Risks are probably underestimated by physicians. Information given to patients seems insufficient or unsuitable (too complex).

Challenges in the prevention of venous thromboembolism in the elderly

Aging itself is a risk factor for venous thromboembolism, and the prevalence in the elderly of additional risk factors (e.g. cancer, orthopedic surgery, immobility) increase its intrinsic risk. Many in the medical community are reluctant to prescribe anticoagulation (for primary and secondary prevention of venous thromboembolism) to their geriatric patients for the fear that bleeding complications may outweigh the benefits. A thorough analysis of the data support the concept that the under-use of heparin in primary prevention in the elderly is more related to medical beliefs than to facts. The risk of bleeding due to oral anticoagulants (secondary prevention) is greatly reduced by keeping the International Normalized Ratio (INR) values within therapeutic ranges and carefully avoiding conditions/drugs that may interfere with such treatment. The oral direct thrombin inhibitor ximelagatran has been studied for primary (hip and knee replacement surgery) and for secondary prophylaxis of venous thromboembolism, and for acute venous thromboembolism treatment. The selective factor Xa inhibitor fondaparinux has been approved for primary prophylaxis of venous thromboembolism in hip and knee replacement surgery and in hip fracture surgery. Studies on the latter drugs, where most of the patients were > 65 years of age, further show that the fear of bleeding complications due to anticoagulation in the elderly is largely unjustified.

Impact d’un programme d’éducation thérapeutique sur les attitudes de prévention vis-à-vis du risque iatrogène : étude pilote contrôlée visant les patients sous anticoagulants oraux pour maladie thromboembolique veineuse

OBJECTIVE

Adverse events related to oral anticoagulants represent a major public health problem. Including patient education as part of the prevention strategy could contribute to improved effectiveness and safer use of drugs. The present study aimed at evaluating the outcomes of a patient education program inspired by recommendations from French Health Authorities (AFSSAPS) and based on an "individual guidance" approach.

METHOD

The study was conducted in two groups of hospitalized patients treated with oral anticoagulants for thromboembolic disease. Each patient in the first (intervention) group attended an individual teaching session conducted at discharge by a trained pharmacist. Patients in the second (control) group were given usual care. These two groups were compared at inclusion (before intervention) and three months later. The outcomes considered were the acquisition of: 1) knowledge, 2) risk anticipation and compliance behaviours characterized by the stability of INR and the incidence of hemorrhagic episodes during the period of observation.

RESULTS

Fifty-nine patients (average age 65 years) were included (29 in the intervention group and 30 in the control group). Three months after the intervention, the intervention group exhibited 1) better knowledge (higher rate of restitution of treatment-related information--name of the drug, administration plan, targeted range for INR (...), interpretation of INR results (p<0.05), management of a specific scenario where INR declines concomitant to elevation of anticoagulant dose (p<0.05)); 2) higher rates of relevant behaviours (p<0.05)--in the event of a missed dose, anticipating an event with a high risk of bleeding, dealing with signs of overdose--and higher compliance profile (ns) (stability of INR, and number of hemorragic episodes). A multivariate model integrating the potential explanatory variables for frequency of hemorrhagic episodes at 3 months (demographic data, history of thrombotic disease, INR stability, reference group (intervention/control)), showed that the only variable significantly associated with frequency of bleeding events was the reference group of the patient (p=0.05; odds-ratio=4.5, interval of confidence: [1-21]).

CONCLUSION

Multivariate analysis demonstrated that the probability of developing a hemorrhagic event when taking an oral anticoagulant is on average 4-fold greater in patients given usual care than in patients given individual guidance a pharmacist. A larger randomized trial is currently under way in the Rhône-Alpes region, France, to validate these exploratory results.

Cardiovascular drug therapy in the elderly: theoretical and practical considerations

The elderly population is expanding rapidly throughout the world. Hypertension, heart disease and other cardiovascular disorders are prevalent conditions among this age group. Consequently, clinicians will spend a large proportion of their practices managing older adults with cardiovascular disorders. A large proportion of this time will be devoted to using pharmacotherapeutic strategies for the long-term management of chronic conditions. The physiological changes that accompany aging affect cardiovascular function, and the pharmacokinetics and pharmacodynamics of many cardiovascular medications are altered by these physiological changes. The interactions of these changes can have a profound effect on the agents used to treat cardiovascular disorders and may alter their therapeutic outcomes. Several classes of medications are used to treat chronic cardiovascular disorders in older adults. These include the ACE inhibitors and angiotensin II receptor antagonists, calcium channel antagonists, beta-adrenoceptor antagonists (beta-blockers), oral antiarrhythmic agents and warfarin. Drugs such as beta-blockers may aggravate decreased cardiac output and increase peripheral resistance, but are valuable adjuncts in many patients with congestive heart failure. Agents that reduce angiotensin II activity may have several benefits for treating heart failure and hypertension. Successful treatment of cardiovascular disorders in older adults requires the choice of the most appropriate agent, taking into consideration the complex interactions of pharmacokinetics, pharmacodynamics and disease effects.

Low rate of bleeding and thrombotic complications of oral anticoagulant therapy independent of age in the real-practice of an anticoagulation clinic

Over past years, there has been a world-wide increase in oral anticoagulant treatment (OAT). This study was aimed at evaluating the efficacy and safety of OAT managing in a real-practice situation. Nine hundred and three consecutive unselected patients referred for the control of OAT to the Anticoagulation Clinic of the University of Florence were studied. The total follow-up period was 1679 patient-years. The rate of total, major and fatal bleeding events was 5.0, 1.1 and 0.06 per 100 patient-years, respectively. In patients with a target International Normalized Ratio (INR) > or = 3, a significantly higher rate of bleeding (P = 0.02) with respect to patients with a target INR < 3 was observed. The rate of all thrombotic events was 3.8 per 100 patient-years. The rate of major and fatal thrombotic events were 2.4 and 0.4 per 100 patient-years, respectively. At INR >/= 4.5 the rate of bleeding was significantly higher (P = 0.005) than at lower INR. At INR < 2 the rate of all thrombotic events was significantly higher (P = 0.00001) with respect to more elevated intensities of anticoagulation. A low incidence of complications may be obtained even in elderly outpatients on OAT followed at an anticoagulation clinic.

[Determination of regimen fluindione needed for anticoagulation in the elderly]

INTRODUCTION

There is no validated method to predict the daily maintenance dosage of oral anticoagulation treatment by fluindione in the elderly patients. The aim of our prospective study was to look for a relation between INR at day 2 after a fixed dosage of fluindione and the daily maintenance dosage of fluindione necessary to obtain an INR value between 2 and 3.

PATIENTS AND METHODS

Ten milligrams of fluindione were administered on first and second day of treatment. INR was determined the third day.

RESULTS

From this value, we were able to determine the daily dosage of fluindione (+/- 5mg) that maintained a steady state INR value between 2 and 3.

CONCLUSION

In these very elderly patients, there was a relation between INR at the third day after a fixed dosage of fluindione and the daily maintenance dosage of fluindione necessary to obtain an INR value between 2 and 3.

What happens after a lung scan? Management and outcome of patients in a regional hospital

Pulmonary embolism (PE) remains a common preventable cause of death in hospitalized patients. The purpose of this study is to examine the in-hospital management, complications of treatment and clinical outcomes of inpatients undergoing lung scintigraphy for the diagnosis of PE in a regional hospital. Two hundred consecutive inpatients with suspected PE were enrolled. The results of lung scans, stratified according to the probability of pulmonary embolism, were correlated with anticoagulation status, discharge diagnosis, haemorrhagic complications and clinical outcome at 6 months. The use of complementary imaging investigations was also determined. Other imaging was performed infrequently (Doppler ultrasound in 18% of patients, CT pulmonary angiography (CT-PA) in 0.5% and conventional pulmonary angiography in 4% of patients). Long-term anticoagulation was initiated in 66 patients (33%), including 10 with intermediate probability lung scans (IPLS) who had no further investigations. Major haemorrhage occurred in 14% of all long-term anticoagulated patients followed up. The recognized recurrence rate was very low (3%) and there was no documented mortality from PE. Most patients with suspected PE are treated on the basis of the lung scan result without further tests. However, other imaging (especially CT-PA and conventional pulmonary angiography) should be performed prior to anticoagulation in patients with IPLS in whom the diagnosis is in doubt. Standard anticoagulation for 6 months appears to be effective for PE, and the recurrence rate is low. However, it has a significant risk of major haemorrhagic complications.

Use of cardiovascular medications in the elderly

Cardiovascular disease is the leading cause of death in patients aged 65 and above. Although elderly persons represent only 12.4% of the US population, they account for about a third of drug expenditures. However the appropriate use of cardiovascular medications in these patients has been shown to reduce the rate of cardiovascular morbidity and mortality. The normal aging and the disease process in the elderly result in significant changes at the structural and molecular level in the elderly. The changes that take place in the autonomic nervous system, the kidneys, and the liver in the elderly modify the metabolism and clinical effects of most medications. Elderly patients are also susceptible to side effects and adverse drug reactions. Physicians should have a clear understanding of the normal aging processes, the abnormal changes due to disease process and the changes in the pharmacology of drugs in the elderly to deliver proper care to the elderly patient.

Management of haemorrhagic complications associated with oral anticoagulant treatment

The frequency of anticoagulant-related bleeding has been reported to range 1-7% per year, depending on the indication for anticoagulant therapy and the classification of bleeding. Although most bleeding is not life threatening, it does cause short-term morbidity and inconvenience to patients, as well as possibly diminishing their quality of life to some degree. Assessing the risk of anticoagulant-related bleeding is integral to optimising the management of anticoagulant therapy. Furthermore, early recognition and treatment of anticoagulant-related bleeding can reduce the associated morbidity. This article reviews the definitions of major and minor bleeding, the assessment of risk and preventive strategies and the management of anticoagulant-related bleeding.

Hemorrhagic complications of oral anticoagulant therapy

Hemorrhage is the major complication of anticoagulant therapy. The criteria for classifying the severity of bleeding has varied between studies, which has resulted in variability in the rate of bleeding reported in the literature. The major determinants of oral anticoagulant-related bleeding are the intensity of the anticoagulant effect, baseline patient characteristics, and the length of therapy. Older patients have characteristics that may place them at higher risk for anticoagulant-related bleeding, but they also have characteristics that make them more likely to benefit. The risk for anticoagulant-related bleeding cannot be considered in isolation and the potential benefits need to be weighed carefully in each individual patient, irregardless of age.

Evaluation of warfarin initiation regimens in elderly inpatients

STUDY OBJECTIVE

To compare initial warfarin doses of 5 mg or below and doses above 5 mg in hospitalized elderly.

DESIGN

Retrospective review of charts identified from computerized pharmacy records.

SETTING

County teaching hospital.

PATIENTS

Inpatients aged 65 years or older receiving at least three warfarin doses.

INTERVENTION

We measured the time to first international normalized ratio (INR) of 2.0 or greater, bleeding complications, number of warfarin doses held, and vitamin K use.

MEASUREMENTS AND MAIN RESULTS

The average initial low dose (33 patients) was 4.8 +/- 0.8 mg and the average initial high dose (40 patients) was 9.0 +/-1.2 mg. The mean time to first INR of 2.0 or greater was similar, 3.4 and 3.0 days, respectively (p=0.38). The low-dose group had fewer bleeds (7 vs 13, p=0.28) and doses held (11 vs 18 patients, p=0.27, 30 vs 50 doses). Four patients in each group received vitamin K (p=0.8). Forty-four percent of patients with an INR of 4 or above and 48% of patients who had a dose held were on a long-term drug or had a new drug added that could cause a major drug interaction with warfarin.

CONCLUSION

In this pilot study, hospitalized elderly who received a low versus high initial dose of warfarin achieved therapeutic INRs in a similar time and had lower but not significantly different safety outcomes.

Warfarin use among ambulatory patients with nonvalvular atrial fibrillation: the anticoagulation and risk factors in atrial fibrillation (ATRIA) study

BACKGROUND

Warfarin dramatically reduces the risk for ischemic stroke in nonvalvular atrial fibrillation, but its use among ambulatory patients with atrial fibrillation has not been widely studied.

OBJECTIVE

To assess the rates and predictors of warfarin use in ambulatory patients with nonvalvular atrial fibrillation.

DESIGN

Cross-sectional study.

SETTING

Large health maintenance organization.

PATIENTS

13428 patients with a confirmed ambulatory diagnosis of nonvalvular atrial fibrillation and known warfarin status between 1 July 1996 and 31 December 1997.

MEASUREMENTS

Data from automated pharmacy, laboratory, and clinical-administrative databases were used to determine the prevalence and determinants of warfarin use in the 3 months before or after the identified diagnosis of atrial fibrillation.

RESULTS

Of 11082 patients with nonvalvular atrial fibrillation and no known contraindications, 55% received warfarin. Warfarin use was substantially lower in patients who were younger than 55 years of age (44.3%) and those who were 85 years of age or older (35.4%). Only 59.3% of patients with one or more risk factors for stroke and no contraindications were receiving warfarin. Among a subset of "ideal" candidates to receive warfarin (persons 65 to 74 years of age who had no contraindications and had previous stroke, hypertension, or both), 62.1% had evidence of warfarin use. Among our entire cohort, the strongest predictors of receiving warfarin were previous stroke (adjusted odds ratio, 2.55 [95% CI, 2.23 to 2.92]), heart failure (odds ratio, 1.63 [CI, 1.51 to 1.77]), previous intracranial hemorrhage (odds ratio, 0.33 [CI, 0.21 to 0.52]), age 85 years or older (odds ratio, 0.35 [CI, 0.31 to 0.40]), and previous gastrointestinal hemorrhage (odds ratio, 0.47 [CI, 0.40 to 0.57]).

CONCLUSIONS

In a large, contemporary cohort of ambulatory patients with atrial fibrillation who received care within a health maintenance organization, warfarin use was considerably higher than in other reported studies. Although the reasons why physicians did not prescribe warfarin could not be elucidated, many apparently eligible patients with atrial fibrillation and at least one additional risk factor for stroke, especially hypertension, did not receive anticoagulation. Interventions are needed to increase the use of warfarin for stroke prevention among appropriate candidates.

Epidemiology of adverse drug reactions in the elderly by drug class

As the growth of the elderly population continues, the burden on the health care system and society will also increase. Since chronic diseases such as hypertension, coronary artery disease, arthritis, stroke, cancer and diabetes mellitus are more prevalent with age, the number of people with multiple chronic diseases will also increase. These patients are likely to be treated for some or all of their conditions with drug therapies. When used appropriately, drugs may be the single most important intervention in the care of an older patient, but when used inappropriately they no longer provide therapeutic benefit, and they may even endanger the health of an older patient by causing an adverse drug reaction (ADR). Factors believed to be responsible for increased adverse reactions in elderly patients are polypharmacy (including prescription and over-the-counter medications), increased drug-drug interaction, pharmacokinetic changes, pharmacodynamic changes, the pathology of aging and compliance. The exact role that age plays in ADRs is not clear. This is in part because few older patients are included in the large randomised trials, and so much of the information used to ascertain the age-associated risks of drugs comes from observational studies. Although the interactions of aging, concurrent comorbidities and polypharmacy are known, older patients do appear to be at increased risk. Improvements in the management of drug therapies of older patients can lead to improvements in their overall health, functioning and safety, as well as providing potential benefits to society by ameliorating some of the burden of their health care.

Ultrasound surveillance for asymptomatic deep venous thrombosis after total joint replacement

Prospective data on 202 consecutive patients who had a total of 123 total hip and ninety-four total knee arthroplasties were collected from two university medical centers. The findings of routine surveillance for deep venous thrombosis performed with ascending contrast venography were compared with those of surveillance with duplex ultrasonography complemented with color-flow Doppler imaging. All of the studies were performed between the third and seventh postoperative days. Of the 202 patients (342 extremities) who were examined, fifty-five (27 per cent) were found to have deep venous thrombosis; fifty-two (95 per cent) of the thrombi were in the calf and three (5 per cent) were in the proximal veins. All of the thrombi were clinically asymptomatic and all were nonocclusive, allowing passage of contrast medium around an intraluminal filling defect. Duplex ultrasonography with color-flow Doppler imaging correctly identified two of the three proximal thrombi and five of the fifty-two thrombi in the calf (sensitivity, 10 per cent). The sensitivity for the detection of thrombi in the calf was zero of sixteen at one of the institutions involved in the study and 14 per cent (five of thirty-six) at the other. There were two false-positive findings on ultrasonographic examination; one involved a proximal thrombus and one, a distal thrombus. We believe that the interinstitutional variability and insensitivity of duplex ultrasonography with color-flow Doppler imaging for the detection of asymptomatic deep venous thrombi in the calf after total joint replacement make it unreliable as a routine surveillance tool after total hip or knee arthroplasty.

The risks of minor head injury in the warfarinised patient

The risk factors affecting intracranial haemorrhage in warfarinised patients are described and an attempt made to calculate the risk of haemorrhage in warfarinised patients with minor head injuries. Using the data from studies of patients with spontaneous haemorrhage while taking warfarin, guidelines for treatment and given and the likely outcome predicted.

CT of hemorrhagic complications of anticoagulant therapy

Anticoagulant therapy is commonly used in patients at risk for, or known to have, thromboembolic disease. Although complications of therapy are uncommon in most patients, in others it may result in complications with substantial morbidity and occasionally may be life threatening. This essay reviews the role of anticoagulant therapy and defines the potential complications that may occur in the chest, abdomen, musculoskeletal system, and CNS. Specific pitfalls in diagnosis as well as complications of the bleeding process are discussed and illustrated. The role of CT scanning in the diagnosis and triage of these patients is clearly defined through select cases and clinical dilemmas.

Bleeding complications of oral anticoagulant treatment: an inception-cohort, prospective collaborative study (ISCOAT). Italian Study on Complications of Oral Anticoagulant Therapy

BACKGROUND

Bleeding is the most serious complication of the use of oral anticoagulation in the prevention and treatment of thromoboembolic complications. We studied the frequency of bleeding complications in outpatients treated routinely in anticoagulation clinics.

METHODS

In a prospective cohort from thirty-four Italian anticoagulation clinics, 2745 consecutive patients were studied from the start of their oral anticoagulation (warfarin in 64%, acenocourmarol in the rest). The target anticoagulation-intensity was low (international normalised ratio [INR] < or = 2.8) in 71% of the patients and high (> 2.8) in the remainder. We recorded demographic details and the main indication for treatment and, every 3-4 months, INR and outcome events. Such events included all complications (bleeding, thrombosis, other), although only bleeding events are reported here, and deaths. We divided bleeding into major and minor categories.

FINDINGS

43% of the patients were women. Nearly three-fifths of the patients were aged 60-79; 8% were over 80. The main indication for treatment was venous thrombolism (33%), followed by non-ischaemic heart disease (17%). Mean follow-up was 267 days. Over 2011 patient-years of follow-up, 153 bleeding complications occurred (7.6 per 100 patient-years). 5 were fatal (all cerebral haemorrhages, 0.25 per 100 patient-years), 23 were major (1.1), and 125 were minor (6.2). The rate of events was similar between sexes, coumarin type, size of enrolling centre, and target INR. The rate was higher in older patients: 10.5 per 100 patient-years in those aged 70 or over, 6.0 in those aged under 70 (relative risk 1.75, 95% Cl 1.29-2.39, p < 0.001). The rate was also higher when the indication was peripheral and/or cerebrovascular disease than venous thromboembolism plus other indications (12.5 vs 6.0 per 100 patient-years) (1.80, 1.2-2.7, p < 0.01), and during the first 90 days of treatment compared with later (11.0 vs 6.3, 1.75, 1.27-2.44, p < 0.001). A fifth of the bleeding events occurred at low anticoagulation intensity (INR < 2, rate 7.7 per 100 patient-years of follow-up). The rates were 4.8, 9.5, 40.5, and 200 at INRs 2.0-2.9, 3-4.4, 4.5-6.9, and over 7, respectively (relative risks for INR > 4.5, 7.91, 5.44-11.5, p < 0.0001).

INTERPRETATION

We saw fewer bleeding events than those recorded in other observational and experimental studies. Oral anticoagulation has become safer in recent years, especially if monitored in anticoagulation clinics. Caution is required in elderly patients and anticoagulation intensity should be closely monitored to reduce periods of overdosing.

Outpatient anticoagulation issues for the primary care physician

Increasingly, primary care providers are caring for patients who require anticoagulation. In this article the indications for, complications of, and methods of dosing and monitoring warfarin in the outpatient setting are reviewed. Heparin use among ambulatory patients also is discussed.