MADISON, WISC. – Patients with ankylosing spondylitis had a small but significant reduction in risk for cardiovascular events if they were taking cyclooxygenase-2 (COX-2) inhibitors, according to a new systematic review and meta-analysis.
The reduced risk observed in this analysis (risk ratio, 0.48; 95% confidence interval, 0.33-0.70) contrasts with the increased risk for cardiovascular events seen with COX-2 inhibitor use in the general population, said Paras Karmacharya, MBBS, speaking in an interview at the annual meeting of the Spondyloarthritis Research and Treatment Network (SPARTAN). The overall effect was highly statistically significant (P = .0001), and the finding provides “reassuring” data for a population that’s known to have an elevated risk for cardiovascular events, he said.
“[W]e found in the subgroup analysis that COX-2 inhibitors were associated with a reduced risk of cardiovascular events as a whole,” an association also seen when looking just at ischemic stroke, Dr. Karmacharya said. “So that was sort of surprising; in the general population, there are some concerns about using COX-2 inhibitors.”
Looking at data for the nine studies that met criteria for inclusion in the meta-analysis, Dr. Karmacharya, a rheumatology fellow at the Mayo Clinic, Rochester, Minn., and his collaborators calculated risk ratios for a composite outcome of all cardiovascular events (CVE) for all individuals taking NSAIDs, compared with individuals with ankylosing spondylitis (AS) who were not taking NSAIDs. Here, they found a relative risk of 0.94 (95% CI, 0.50-1.75; P = .84).
Next, the investigators calculated a relative risk of 0.78 for the composite CVE outcome just for those taking nonselective NSAIDs (95% CI, 0.44-1.38; P = .40).
Along with NSAIDs, Dr. Karmacharya and his coauthors also looked at the relationship between tumor necrosis factor inhibitors (TNFIs) and cardiovascular events. They found a significantly increased risk for the composite endpoint among AS patients taking TNFIs (RR, 1.60; 95% CI, 1.05-2.41; P = .03), but the comparison was limited to only one study.
In their analysis, the investigators also broke out risk of acute coronary syndrome (ACS)/ischemic heart disease. “The only place where we found some increased risk was ACS and ischemic heart disease, and that was with nonselective NSAIDS,” Dr. Karmacharya said (RR, 1.21; 95% CI, 1.06-1.39; P = .005). No significant changes in relative risk for ACS and ischemic heart disease were seen for the total group of NSAID users, for the subgroups taking COX-2 inhibitors, or for those taking TNFIs.
Finally, the investigators found a relative risk of 0.58 for stroke among the full group of NSAID users and a relative risk of 0.59 for those taking COX-2 inhibitors, but no reduced risk for the subgroup taking nonselective NSAIDs (P = .02, .04, and .37, respectively).
“While NSAIDs are known to be associated with an increased risk of CVE in the general population, whether the anti-inflammatory effects of NSAIDs reduce or modify the CVE risk in AS is controversial,” Dr. Karmacharya and his collaborators wrote. In this context, the meta-analysis provides a useful perspective for rheumatologists who care for AS patients, Dr. Karmacharya said: “I think it’s important, because most of these patients are on NSAIDs long-term.”
However, all of the studies included in the meta-analysis were observational, with no randomized, controlled trials meeting inclusion criteria. Also, some analyses presented in the poster involved as few as two studies, so findings should be interpreted with caution, he added. “We don’t have a lot of studies included in the analysis. ... so we need more data for sure, but I think what data we have so far look reassuring.”
Dr. Karmacharya reported that he had no conflicts of interest, and reported no outside sources of funding.