Increased risk for stroke in patients with familial Mediterranean fever: results from a large population-based study

Objective: The association between chronic inflammatory conditions and cardiovascular disease is well established. Considering FMF, few studies exist investigating the risk of ischaemic heart disease, and none address the risk of stroke. We aimed to evaluate the incidence and risk for stroke in FMF patients compared with the general population. Methods : A retrospective cohort study using the electronic database of Clalit Health Services (CHS), the largest health organization in Israel. All FMF patients diagnosed between 2000 and 2016 were included and matched with control according to age, gender and place of residence. Follow-up continued until the first diagnosis of stroke or death. The incidence of stroke was compared between the groups using univariate and multivariate models adjusting for cardiovascular risk-factors. Results: A total of 9769 FMF patients and a similar number of controls were followed up for a median period of 12.5 years. The mean age at the beginning of the follow-up was 25.7 years. In total, 208 FMF patients were diagnosed with stroke compared with 148 controls, resulting in an incidence rate (per 10 000 persons-years) of 19.8 (95% CI 17.2, 22.7) and 13.9 (95% CI 11.8, 16.4), respectively, and a crude HR of 1.42 (95% CI 1.15-1.76; P < 0.001). In a multivariate analysis, FMF patients who developed amyloidosis with related or non-related renal failure demonstrated significant stroke risk (HR = 2.16; 95% CI 1.38, 3.38; P < 0.001), as well as for those who did not develop these complications (HR = 1.32; 95% CI 1.04, 1.67; P < 0.05). Conclusion: FMF patients are at increased risk for stroke regardless of known complications.