Cyclo-oxygenase-2 (COX-2) selective inhibitors have been associated with an increased risk of thrombotic cardiovascular events in placebo-controlled trials, but no clinical trial has been reported with the primary aim of assessing relative cardiovascular risk of these drugs compared with traditional non-steroidal anti-inflammatory drugs (NSAIDs). The MEDAL programme was designed to provide a precise estimate of thrombotic cardiovascular events with the COX-2 selective inhibitor etoricoxib versus the traditional NSAID diclofenac.
Researchers designed a prespecified pooled analysis of data from three trials in which patients with osteoarthritis or rheumatoid arthritis were randomly assigned to etoricoxib (60 mg or 90 mg daily) or diclofenac (150 mg daily). The primary hypothesis stated that etoricoxib is not inferior to diclofenac, defined as an upper boundary of less than 1.30 for the 95% CI of the hazard ratio for thrombotic cardiovascular events in the per-protocol analysis. Intention-to-treat analyses were also done to assess consistency of results. These trials are registered at http://www.clinicaltrials.gov with the numbers NCT00092703, NCT00092742, and NCT00250445. Researchers enrolled 34 701 patients (24 913 with osteoarthritis and 9 787 with rheumatoid arthritis). Average treatment duration was 18 months (SD 11.8). 320 patients in the etoricoxib group and 323 in the diclofenac group had thrombotic cardiovascular events, yielding event rates of 1.24 and 1.30 per 100 patient-years and a hazard ratio of 0.95 (95% CI 0.81-1.11) for etoricoxib compared with diclofenac. Rates of upper gastrointestinal clinical events (perforation, bleeding, obstruction, ulcer) were lower with etoricoxib than with diclofenac (0.67 vs 0.97 per 100 patient-years; hazard ratio 0.69 [0.57-0.83]), but the rates of complicated upper gastrointestinal events were similar for etoricoxib (0.30) and diclofenac (0.32). Researchers concluded that rates of thrombotic cardiovascular events in patients with arthritis on etoricoxib are similar to those in patients on diclofenac with long-term use of these drugs.(Source: PMID: 17113426 [PubMed – in process]: Lancet. 2006 Nov 18;368(9549):1771-81.)