Effects of colchicine on risk of cardiovascular events and mortality among patients with gout: a cohort study using electronic medical records linked with Medicare claims

Background Colchicine may have beneficial effects on cardiovascular (CV) disease, but there are sparse data on its CV effect among patients with gout. We examined the potential association between colchicine and CV risk and all-cause mortality in gout. Methods The analyses used data from an electronic medical record (EMR) database linked with Medicare claims (2006-2011). To be eligible for the study cohort, subjects must have had a diagnosis of gout in the EMR and Medicare claims. New users of colchicine were identified and followed up from the first colchicine dispensing date. Non-users had no evidence of colchicine prescriptions during the study period and were matched to users on the start of follow-up, age and gender. Both groups were followed for the primary outcome, a composite of myocardial infarction, stroke or transient ischaemic attack. We calculated HRs in Cox regression, adjusting for potential confounders. Results We matched 501 users with an equal number of non-users with a median follow-up of 16.5months. During follow-up, 28 primary CV events were observed among users and 82 among non-users. Incidence rates per 1000 person-years were 35.6 for users and 81.8 for non-users. After full adjustment, colchicine use was associated with a 49% lower risk (HR 0.51, 95% CI 0.30 to 0.88) in the primary CV outcome as well as a 73% reduction in all-cause mortality (HR 0.55, 95% CI 0.35 to 0.85, p=0.007). Conclusions Colchicine use was associated with a reduced risk of a CV event among patients with gout.