Incidence of VTE, Stroke in GCA and Non-GCA Comparators

Patients with giant cell arteritis (GCA) are not at increased risk for developing venous thromboembolism (VTE), stroke, or transient ischemic attack (TIA) compared with those without GCA, data published in PLoS ONE indicate.¹

Despite the typical arterial inflammation associated with headache, scalp tenderness, and vision loss in GCA, stroke is uncommon in this population.^2-4 Previous studies that found an increased risk of stroke in this population were limited by use of retrospective administrative data with no objective confirmation of diagnosis.^5-7

In the present study led by Alberto Lo Gullo, MD, of the University of Messina in Messina, Italy, researchers retrospectively evaluated the risk of TIA and VTE in 244 patients with GCA and 240 matched healthy controls for whom complete medical records were available. 

Mean age at diagnosis was 76.2 years. At baseline, patients with GCA were more likely to be taking aspirin (22.4% GCA vs 14.5% non-GCA; P = .028), while controls were more likely to be taking a lipid-lowering medication (16.5% non-GCA vs 9.6% GCA; P = .027) and to have diabetes (16.7% non-GCA vs 6.6% GCA; P = .001). No significant difference in anticoagulant use at time of GCA diagnosis or index date was noted.

Over the course of follow-up, 16 incident VTE events (6 deep vein thrombosis [DVT] alone, 4 pulmonary embolism [PE] alone, 6 DVT and PE) occurred in the GCA cohort compared with 10 events in the control group. At 10 years post-GCA diagnosis, the cumulative incidence of VTE was similar between both groups (cumulative incidence [CI] ± standard error [SE]; 6.3 ± 1.6 vs 3.7 ± 1.3, respectively; P = .22), with the overall rate of VTE events 6.6 per 1000 person-years in the GCA cohort vs 3.9 per 1000 person-years in the control group (rate ratio [RR]; 95% confidence interval [CI], 1.64 [0.77- 3.74]).

Thirty cerebrovascular events (21 stroke alone, 4 amaurosis fugax alone, 3 TIA and stroke, 1 amaurosis fugax and TIA, 1 amaurosis fugax, 0 TIA and stroke) occurred in the GCA group compared with 27 events (1 TIA alone, 23 stroke alone, 0 amaurosis fugax, 3 TIA and stroke) in the control group, with no difference in vascular territory observed. 

At 10-year follow-up, the cumulative incidence of cerebrovascular events was similar between both groups, though the GCA group had a higher incidence of amaurosis fugax compared with controls. The overall rate of cerebrovascular events was 13.0 per 1000 person-years in the GCA group vs 11.0 per 1000 person-years in the control group (RR; 95% CI, 1.18 [0.70-1.99]).

Notably, the researchers found no baseline GCA characteristics, laboratory measures, comorbidities, or medications to be associated with an increased risk of VTE or cerebrovascular events during follow-up.

“In this population-based cohort, patients with GCA were at an increased risk for amaurosis fugax; however, the risk of VTE, stroke, and TIA was similar to non-GCA subjects,” the authors concluded. “Further population-based studies with control subject comparison are needed to confirm these findings.”

Limitations and Disclosures  

• Low overall frequency of VTE and cerebrovascular event rate may not have allowed identification of small magnitudes of increased risk
• Comparator group may have inherently had increased risk of developing cerebrovascular events (due to increased risk factors) 

The study was funded by the Rochester Epidemiology Project, which is supported by the US National Institute on Aging of the National Institutes of Health (NIH). The study authors reported no relevant disclosures. 

References

1. Lo Gullo A, Koster MJ, Crowson CS, et al. Venous thromboembolism and cerebrovascular events in patients with giant cell arteritis: a population- based retrospective cohort study. PLoS ONE. 2016;11(2):e0149579.
2. Gonzalez-Gay MA, Vazquez-Rodriguez TR, Gomez-AceboI, et al. Strokes at time of disease diagnosis in a series of 287 patients with biopsy-proven giant cell arteritis. Medicine (Baltimore). 2009;88(4):227-235.
3. Samson M, Jacquin A, Audia S, et al. Stroke associated with giant cell arteritis: a population-based study. J Neurol Neurosurg Psychiatr. 2015;86(2):216-221.
4. Wiszniewska M, Devuyst G, Bogousslavsky J. Giant cell arteritis as a cause of first-ever stroke.Cerebrovasc Dis. 2007;24(2-3):226-230.
5. Ray JG, Mamdani MM, Geerts WH. Giant cell arteritis and cardiovascular disease in older adults. Heart. 2005;91(3):324-328.
6. Tomasson G, Peloquin C, Mohammad A, et al. Risk for cardiovascular disease early and late after a diagnosis of giant-cell arteritis: a cohort study. Ann Intern Med. 2014;160(2):73-80.
7. Amiri N, De Vera M, Choi HK, Sayre EC, Avina-Zubieta JA. Increased risk of cardiovascular disease in giant cell arteritis: a general population-based study. Rheumatology (Oxford). 2016;55(1):33-40.

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