The risk of acute thromboembolic cardiovascular events in association with use of chondroitin sulphate: A comparative, propensity score-matched cohort study using Swiss healthcare claims data.

ObjectiveWe aimed to evaluate the risk of acute thromboembolic cardiovascular events in new chondroitin (sulphate) users compared to new users of intraarticular (IA) steroids in a propensity score (PS)-matched cohort study.MethodUsing Swiss healthcare claims data (2013-2022, study period), we identified new users of chondroitin and IA steroids aged 40-99 years. Primary outcome was an inpatient-diagnosed myocardial infarction, ischemic stroke, or transient ischemic attack. The secondary outcome additionally included all-cause mortality. After PS matching, we calculated incidence rates (IRs) and estimated hazard ratios (HRs) with 95% confidence intervals (CIs). In a sensitivity analysis, we restricted to patients with imaging of the hip/knee and a claim for NSAIDs within 365 days before cohort entry to increase likelihood of them having osteoarthritis (OA).ResultsAfter matching, we included 36,659 chondroitin users and 37,501 IA steroid users. Matched IRs for the primary outcome were 9.6 for chondroitin and 11.9/1000 py for IA steroids, yielding a matched (m)HR of 0.81 (95% CI 0.69-0.95). The sensitivity analysis yielded a mHR of 0.79 (95% CI 0.56-1.11). IRs for the secondary outcome were 18.9 and 29.2/1000 py for chondroitin and IA steroid users, resulting in a mHR of 0.67 (95% CI 0.60-0.75).ConclusionChondroitin use was associated with a slightly lower risk of cardiovascular events compared to IA steroid use. However, residual confounding by patient frailty may explain the finding to some degree, given the excess mortality in the comparison group. Further research is needed to corroborate or refute a potential cardioprotective effect of chondroitin.