OBJECTIVE - Osteoarthritis (OA) is a common cause of joint pain and disability, and effective treatments are lacking. Extracellular adenosine has anti-inflammatory effects and can prevent and treat OA in animal models. Ticagrelor and clopidogrel are both used in patients with coronary artery disease, but only ticagrelor increases extracellular adenosine. The aim of this study was to determine whether treatment with ticagrelor was associated with a lower risk of OA.

METHODS - We conducted a 1:2 propensity score matching analysis using the Optum Clinformatics™ Data Mart from 2011 to 2017. We included patients who received either ticagrelor or clopidogrel for at least 90 days and excluded those with a prior diagnosis of OA or inflammatory arthritis. OA was identified using International Classification of Diseases codes. The primary outcome was the time to diagnosis of OA after treatment with ticagrelor versus clopidogrel.

RESULTS - Our propensity score matched cohort consisted of 7,007 ticagrelor-treated patients and 14,014 clopidogrel-treated patients, with a median number of days on treatment of 287 and 284 respectively. For both groups, the mean age was 64 years, and 73% of the patients were male. Multivariate Cox-regression analysis estimated a hazard ratio of 0.71 (95% CI 0.64-0.79, p<0.001) for developing OA after treatment with ticagrelor compared to clopidogrel.

CONCLUSION - Treatment with ticagrelor was associated with a 29% lower risk of developing OA compared to clopidogrel over five years of follow-up. We hypothesize that the reduction in OA seen in patients who received ticagrelor may in part be due to increased extracellular adenosine.