Increased incidence of giant cell arteritis and associated stroke during the COVID-19 pandemic in Spain: A nation-wide population study

INTRODUCTION: SARS-CoV-2 infection and COVID-19 vaccines might have increased the incidence of giant-cell arteritis (GCA) and the risk of associated stroke in Spain. METHODS: Retrospective nation-wide observational analysis of all adults hospitalized with GCA in Spain during 5 years (Jan-2016 and Dec-2021). The incidence and proportion of admissions with or because of GCA and GCA-associated stroke were compared between pre-pandemic (2016–2019) and pandemic (2020 and 2021) years. Sensitivity analyses were conducted for the different COVID-19 waves and vaccine timing schedules. RESULTS: A total of 17,268 hospital admissions in patients diagnosed with GCA were identified. During 2020 there were 79.3 and 8.1 per 100,000 admissions of GCA and GCA-associated stroke, respectively. During 2021 these figures were 80.8 and 7.7 per 100,00 admissions, respectively. As comparison, yearly admissions due to GCA and GCA-associated stroke were 72.4 and 5.7 per 100,00, respectively, during the pre-pandemic period (p < 0.05). Coincident with the third wave of COVID-19 (and first vaccine dosing), the rate of GCA-associated stroke admissions increased significantly (from 6.7 to 12%; p < 0.001). Likewise, there was an increase in GCA-associated stroke (6.6% vs 4.1%, p = 0.016) coincident with the third dose vaccination (booster) in patients older than 70 at the end of 2021. In multivariate analysis, only patients admitted during the third COVID-19 wave (and first vaccine dosing) (OR = 1.89, 95% CI 1.22–2.93), and during the third vaccination dosing in patients older than 70 (booster) (OR = 1.66, CI 1.11–2.49), presented a higher GCA-associated stroke risk than the same months of previous years after adjustment by age, sex, classical cardiovascular risk factors and COVID-19 diagnosis. CONCLUSIONS: The COVID-19 pandemic led to an increased incidence of GCA during 2020 and 2021. Moreover, the risk of associated stroke significantly risen accompanying times of COVID-19 vaccine dosing, hypothetically linked to an increased thrombotic risk of mRNA-SARS-CoV-2 vaccines. Hence, forthcoming vaccine policies and indications must weigh the risk of severe COVID-19 with the risk of flare or stroke in patients with GCA.