Online Clinical Case Study (March 2010)
The
content of the Office Cardiology Series is provided by:
Dr. LI Siu Lung, Steven FHKAM (Med), FRCP (Glasg), FRCP (Edin), FRCP (Lond),
Specialist in Cardiology.
Dr. WONG Shou Pang, Alexander FRCP, FHKAM (Med.), FHKCP, Specialist in Cardiology
臨床心臟科個案研究之內容誠蒙李少隆醫生及王壽鵬醫生提供。
A 75-year-old lady with chronic non-rheumatic atrial fibrillation was admitted because of a minor stroke. She had previously taken warfarin, but this was stopped a few months ago because of repeated gastrointestinal bleeding due to angiodysplasia of her colon.
Answers
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Is anticoagulation
therapy indicated in this lady? |
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| 2. |
What
would your options be, other than warfarin? |
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Atrial fibrillation is a common disorder and it occurs in up to 10% of people older than 80 years old. It increases the risk of stroke by more than 5 times. Studies have shown that anticoagulation therapy with warfarin can effectively lower the risk of stroke in this population. However, despite its efficacy, warfarin therapy is not always accepted by patients due to the need for frequent blood monitoring, the narrow therapeutic window, and interactions with herbal medicines. In addition, the bleeding risk associated with warfarin therapy may impose a clinical dilemma, as in the current example, where its use may be relatively contraindicated with an active or recurrent bleeding source that cannot be eradicated. Thromboembolism from the left atrial appendage is believed to be the main cause of stroke in these cases. Surgical closure of the left atrial appendage is a routine procedure in many centres for patients undergoing valve or arrhythmia surgery. However, without other co-existing indications for open heart surgery, an open surgery alone for left atrial appendage closure for stroke prevention appears to be too invasive and traumatic for most clinicians and patients to accept. In recent years, there has been development of percutaneuous devices for non-surgical closure, using a transcatheter technique. Various devices are available and they include the Watchman device and the Amplatzer Occluder device. Typically the procedure is done via femoral vein approach. The atrial septum will then be punctured and the device will be delivered to the left atrial appendage via a delivering cable (Figure). The PROTECT-AF trial is a randomized trial comparing the efficacy of the Watchman device with warfarin therapy. Non-inferiority in reducing stroke was demonstrated. Although transcatheter closure appears to be a useful alternative in patients not suitable for long-term anticoagulation therapy, some limitations still exist for these devices. A period of anticoagulation or antiplatetlet therapy is still needed after the procedure, and it may still pose a certain bleeding risk during this period. Substantial procedural risks, such as dislodgment and embolization of the device, perforation with pericardial effusion, and acute peri-operative stroke, have been observed. The risks and benefits of the procedure have to be carefully balanced. At this stage, device therapy for left atrial appendage closure should be limited to highly select patients with favourable cardiac anatomy. Current evidence does not recommend transcatheter closure as a substitution for warfarin therapy in routine situations.
Further reading |
A 35-year-old male complained of skin rash across his trunk for one month. The lesion was only mildly itchy, and he reported no systemic symptoms. He had applied proprietary topical antifungal treatment with no significant improvement. The rash had increased in size in recent days. He denied any preceding contact with allergens or any arthropod bites. He enjoyed good general health with no ongoing drug treatment. Examination showed a large red plaque on his trunk with peripheral erythema, and central hyperpigmentation was noted. There were no vesicles or scaling noted on the border of the lesion.
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| The
content of the Dermatology Series is provided by: Dr. TANG Yuk-ming, William, Dr. CHAN Loi-yuen, Dr. CHAN Hau-ngai, Kingsley & Dr. CHAN Yiu-hoi Specialists in Dermatology & Venereology 皮膚科病例研究之內容誠蒙鄧旭明醫生、陳來源醫生、陳厚毅醫生及陳耀海醫生提供。 |
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