CRA Forum: Dr. Simon Carette’s review

This is the second paper published in the last two years suggesting that aspirin (or anticoagulant therapy) should be used in patients with giant cell arteritis in order to reduce the risk of ischemic events, including visual loss and cerebrovascular accidents (CVA) (1-2). In both studies, patients who were already receiving low-dose aspirin therapy (in most cases because of ischemic heart disease or cerebrovascular risk factors) at the time of diagnosis of GCA had a lower incidence of ischemic events secondary to GCA than patients not on aspirin (OR 0.18, P < 0.15 in the current study and OR 0.22, P=0.02 in Nesher’s study).

Unfortunately, the majority of visual events and strokes secondary to GCA tend to occur at the time of diagnosis of the disease, before the initiation of steroid therapy. This was the case in the current study as 48 (94%) of the 51 ischemic events observed in the 143 patients (45 vision loss and 6 ischemic hemispheric strokes) occurred before treatment with steroids was initiated. Of the 3 events occurring after the diagnosis was made, one involved a patient who was receiving aspirin and two involved patients who were not. In Nesher’s study, the rate of ischemic complications after initiation of steroid therapy was much higher than that reported in any other series. Thus fourteen of 166 patients developed cranial ischemic events during follow-up (vision loss in 8 patients and CVA in 6 patients). In 5 patients, these complications developed within 2 weeks of the initiation of steroids while in the other 9 patients, they occurred during tapering or discontinuation of steroids. However, of the 14 patients, only 2 were on aspirin as opposed to 12 who were not (OR 0.18, P=0.03).

Based on the current evidence, it is now clear that patients who happen to be on aspirin prior to receiving corticosteroids for the treatment of GCA have a lower risk of developing cranial ischemic complications, including visual loss and stroke. What is also reaffirmed by this study is that corticosteroids are extremely effective in reducing the risk of cranial ischemic complications as the latter were observed in only 3/143 (2%) patients after the initiation of therapy as compared to 51/143 (36%) before steroids were prescribed. The question most relevant to clinicians is whether aspirin should be combined to corticosteroids at the time of diagnosis in order to further reduce the risk of ischemic complications. Unfortunately, this question was not answered by the current study and it is unlikely that it will ever be adequately answered as the rate of events is so low that it will be impossible to undertake a randomized placebo controlled trial to properly address it. Also it would be unethical to withdraw aspirin from patients with ischemic heart disease or cerebrovascular risk factors for the sole purpose of conducting such a trial. In his editorial accompanying Nesher’s paper in 2004, Hellmann had taken the position that low-dose aspirin should now be part of the standard of care in patients with GCA (3). Although the results of the present paper do not provide strong support for this recommendation, I, for one, will continue using low-dose aspirin in all my patients with GCA at least during the first month of treatment with corticosteroids and for much longer (eg. the entire duration of treatment with steroids) in patients who have no absolute contraindication to taking aspirin.

Lee MS, Smith SD, Gabor A, Hoffman GS. Antiplatelet and anticoagulant therapy in patients with giant cell arthritis. Arthritis Rheum 2006;54:3306-9
Nesher G, Berkun Y, Mates M, maras M, Rubinow A, Sonneblick M. Low-dose aspirin and prevention of cranial ischemic complications in giant cell arteritis. Arthritis Rheum 2004;50:1332-7
Hellmann DB. Low-dose aspirin in the treatment of giant cell arteritis. Arthritis Rheum 2004;50:1026-7

Review by Dr. SIMON CARETTE, English and French versions
CRA Forum : Review by Dr. SIMON CARETTE, English and French versions