The utilization of antithrombotic prophylaxis for atrial fibrillation in a geriatric rehabilitation hospital

The risk of hemorrhagic complications in hospital in-patients who fall while receiving antithrombotic therapy

BACKGROUND: The use of antithrombotic agents and falls are independently associated with an increased risk of hemorrhagic injury. However, few studies have delineated the risk of fall-related hemorrhagic complications in persons who are taking antithrombotic therapy. The objective of this study was to compare the rates of fall-related hemorrhagic injury in hospital in-patients who are taking and not taking antithrombotic therapy. METHODS: A 4-year retrospective chart review of consecutive patients who fell during admission to a 500-bed tertiary-care teaching hospital was conducted. Major hemorrhagic injuries including subdural hematomas and major bleeding/cuts, patients' use of antithrombotic medication (warfarin, aspirin, clopidogrel and heparin) and their anticoagulation status at the time of their fall were recorded. RESULTS: A total of 2635 falls in 1861 patients were reviewed. Approximately 10% of falls caused major hemorrhagic injury. One fall resulted in a subdural hematoma. Persons taking warfarin were less likely to suffer a fall-related major hemorrhagic injury compared with persons not taking antithrombotic therapy (warfarin, 6%; no therapy, 11%; p = 0.01). Logistic regression showed that fall-related major hemorrhagic injury was associated with female gender (odds ratio 1.6; 95% CI 1.3, 2.1), use of aspirin (odds ratio 1.4; 95% CI 1.1, 1.8) and use of clopidogrel (odds ratio 2.2; 95% CI 1.1, 4.8), but not with the use of warfarin or heparin, or the intensity of anticoagulation. CONCLUSIONS: In this study, compared with persons taking no antithrombotic therapy, those taking warfarin had lower rates of fall-related hemorrhagic injuries. The absolute rate of the development of fall-related intracranial hemorrhagic injury such as subdural hematomas was low, even in persons taking warfarin. These counter-intuitive results may be due to selection bias, and suggest that physicians are very conservative in selecting patients for warfarin therapy, choosing only those who are sufficiently healthy to be at much lower than average risk of suffering fall-related hemorrhagic injuries. This phenomenon may lead to physicians overestimating the potential for fall-related major hemorrhagic injury in persons taking antithrombotic therapy, with the possible denial of warfarin therapy to many of those who would benefit. This perception may contribute to the care gap between the number of patients who would theoretically derive overall benefit from warfarin therapy and those who are actually receiving it.

Transcatheter left atrial appendage occlusion with Amplatzer devices to obviate anticoagulation in patients with atrial fibrillation

It is assumed that over 90% of clinically apparent embolisms in atrial fibrillation originate from the left atrial appendage. Recently, a percutaneous method (PLAATO technique) to occlude the left atrial appendage to the end of preventing thromboembolic complications of atrial fibrillation has been introduced into clinical practice. This technique is quite intricate and requires general anesthesia. The Amplatzer atrial septal occluder lends itself for a more simple approach to this intervention. The first 16 patients treated at four centers are described. Their age varied from 58 to 83 years. All suffered from atrial fibrillation but eight of them were in sinus rhythm at the time of implantation. All but two procedures were done under local anesthesia of the groin only. There was one technical failure (device embolization) requiring surgery. All other patients left the hospital a day after the procedure without complications. There were no problems or embolic events during an overall follow-up of 5 patient-years and all left atrial appendages were completely occluded without evidence of thrombosis at the atrial side of the device at the latest follow-up echocardiography. With the Amplatzer technique, the left atrial appendage can be percutaneously occluded with a venous puncture under local anesthesia, without echocardiographic guidance, and at a reasonable risk. It remains to be evaluated in larger series or randomized trials how the simpler Amplatzer technique compares with the complex PLAATO technique, and whether left atrial appendage closure is competitive with oral anticoagulation with warfarin or the novel ximelagatran to prevent thromboembolism in atrial fibrillation.

Knowledge level and coping strategies according to coagulation levels in older persons with atrial fibrillation

The present study examined the knowledge level and the coping strategies of older persons with atrial fibrillation, who were on oral anticoagulant therapy. The relationship among knowledge level, problem and affective-oriented coping strategies, and the level of anticoagulant effectiveness were examined. We also compared differences between subjects who were within a therapeutic range for International Normalized Ratio levels with those who were not. The research design was descriptive and correlational. One hundred older persons completed the Jaloweic Coping Scale (a knowledge questionnaire) and socio-demographic, contextual and clinical characteristic questions. The findings suggested that the knowledge levels were low (53%), and problem-oriented coping strategies were most often used (32.62%) compared to affective-oriented coping strategies (18.96%). Other than praying and putting one's trust in God (P = 0.05), it appeared that no other significant coping strategies differentiated the subjects regarding their level of anticoagulant effectiveness. It is recommended that further examination of the reasons for older persons' low knowledge level, in regard to their oral anticoagulant therapy, occurs and that use of problem-oriented coping strategies, to improve self-care measures, be encouraged.

Percutaneous left atrial appendage transcatheter occlusion to prevent stroke in high-risk patients with atrial fibrillation: early clinical experience

BACKGROUND

Thromboembolism due to atrial fibrillation (AF) is a frequent cause of stroke. More than 90% of thrombi in AF form in the left atrial appendage (LAA). Obliteration of the appendage may prevent embolic complications.

METHODS AND RESULTS

We evaluated the feasibility and safety of implanting a novel device for percutaneous left atrial appendage transcatheter occlusion (PLAATO). LAA occlusion using the PLAATO system was attempted in 15 patients with chronic AF at high risk for stroke, who are poor candidates for long-term warfarin therapy. The implant consists of a self-expanding nitinol cage covered with a polymeric membrane (ePTFE). The LAA was successfully occluded in 15/15 patients (100%). Angiography and transesophageal echocardiography (TEE) during the procedure showed that the device was well-seated in all patients and that there was no evidence of perforation, device embolization, or interference with surrounding structures. In 1 patient, the first procedure was complicated by a hemopericardium, which occurred during LAA access. A second attempt 30 days later was successful with no untoward sequela. No other complications occurred. At 1-month follow-up, chest fluoroscopy and TEE revealed continued stable implant position with smooth atrial-facing surface and no evidence of thrombus.

CONCLUSIONS

Thus, transcatheter closure of the LAA is feasible in humans. This novel implant technology may be appropriate for patients with AF who are not suitable candidates for anticoagulation therapy. Further trials are needed to show the long-term safety and its efficacy in reducing stroke.

Implementation of antithrombotic management in atrial fibrillation

The aim of the study was to assess the extent to which published recommendations on the antithrombotic management of atrial fibrillation had been adopted into clinical practice in a busy district general hospital, and the impact of clinical audit on subsequent management. In the initial audit, 185 consecutive patients with atrial fibrillation were studied using their case notes to identify any further clinical risk factors for stroke. A management algorithm stratified patients with atrial fibrillation into high, moderate, or low risk of stroke according to the individual stroke risk factors. For patients at high risk, the correct treatment is warfarin unless there are specific contraindications. For patients at moderate risk, the correct management is aspirin unless there are specific contraindications. Patients at low risk should receive no thromboprophylaxis. The clinical risks of stroke and thromboprophylaxis on discharge from hospital were recorded. An extensive education programme on stroke prevention in atrial fibrillation was undertaken. Six months later a further 185 consecutive patients with atrial fibrillation were audited. Overall, a large proportion (306/370; 83%) of patients were at high risk of stroke. In the initial audit, antithrombotic management was correct in 89 patients (48%). In the follow up audit, antithrombotic management was correct in 135 patients (73%) (p < 0. 00001). If this improvement in management were extrapolated to all hospital patients in the United Kingdom, approximately 1400 strokes/year could be avoided. Despite broad consensus in recent publications, antithrombotic management of atrial fibrillation remains imperfect, with many patients exposed to unnecessarily high risk of stroke.

Frequency of anticoagulation for atrial fibrillation and reasons for its non-use at a Veterans Affairs medical center

Randomized clinical trials have led to guidelines for anticoagulation in atrial fibrillation (AF). However, it is unclear how successfully these guidelines are being implemented in clinical practice and there is concern that anticoagulation is underused. Therefore, we examined the rate of anticoagulation in 998 patients with AF who attended a Veterans Affairs Medical Center over a 2-year period. Warfarin was prescribed for 504 patients (51%) and not prescribed for 494 patients (49%). Of these 494 patients, 446 had sufficient data for further assessment. Warfarin was judged not indicated in 200 because AF was transient or lone. Warfarin was indicated in 246 patients, 63% having > or =3 risk factors for thromboembolism. However, 184 of these patients also had at least 1 contraindication to anticoagulation. Thus, warfarin was prescribed to 67% of patients with AF in whom anticoagulation was indicated and to 89% of such patients in whom it was indicated and who had no contraindications. However, 25% of AF patients with strong indications for anticoagulation had concomitant contraindications, which precluded its use. We conclude that the use of warfarin for AF in this setting is higher than previously reported and approaching ideal levels. However, there remains a large, problematic subgroup of patients with AF in whom indications for and contra-indications to anticoagulation coexist.

Primary stroke prevention in nonvalvular atrial fibrillation: implementing the clinical trial findings

OBJECTIVE

To review the clinical trials evaluating warfarin for primary stroke prophylaxis in nonvalvular atrial fibrillation (NVAF), to discuss the relative benefits and risks of warfarin versus aspirin therapy, and to review the clinical practice guidelines and identify potential barriers to their implementation in clinical practice.

DATA SOURCES

A MEDLINE literature search was performed to identify clinical trials of antithrombotic therapy for NVAF, clinical practice guidelines, studies evaluating physician practices and attitudes, cost-effectiveness studies, and pertinent review articles. Key search terms included atrial fibrillation, stroke, antithrombotic, warfarin, aspirin, and cost-effectiveness.

DATA EXTRACTION

Prospective, randomized clinical trials were selected for analysis. Clinical practice guidelines from recognized panels of experts were reviewed. Comprehensive review articles were selected.

DATA SYNTHESIS

NVAF is a common arrhythmia that is associated with a substantial risk for stroke. Seven prospective, randomized, clinical trials have conclusively demonstrated the efficacy of warfarin for stroke prevention. The greatest benefits are achieved in older patients and those with comorbidities that increase their risk for stroke. The potential benefits of preventing a devastating stroke, however, must be weighed against the potential for bleeding complications. Warfarin has been shown to be cost-effective in high-risk patients, provided the rate of complications is minimized. Nonetheless, many physicians remain hesitant to implement warfarin therapy in older, high-risk patients. The clinical data on aspirin are less consistent than those observed with warfarin. Aspirin appears to be most effective in younger individuals or those considered to be at low risk for stroke.

CONCLUSIONS

In patients with NVAF, the personal, social, and economic consequences of stroke are often devastating. Clinical trials have provided definitive proof that the risks of stroke can be significantly reduced through the use of appropriate antithrombotic therapy. Despite this evidence and the recommendations of a number of clinical practice guidelines, variations in care exist that continue to place patients at risk. Additional outcomes research is needed to evaluate the impact of the clinical trial findings and practice guidelines on clinical practice and to develop methods for overcoming barriers to implementation.