Protective effects of methotrexate against ischemic cardiovascular disorders in patients treated for rheumatoid arthritis or psoriasis: novel therapeutic insights coming from a meta-analysis of the literature data

OBJECTIVE The association between chronic use of methotrexate and decreased risk of ischemic cardiovascular events (CVE) among patients with psoriatic or rheumatoid arthritis (RA) was investigated using a systematic review and meta-analysis. METHODS The studies should have recruited adults receiving methotrexate, followed up for at least one year. Moreover, studies should have reported "hard" cardiovascular endpoints, by evaluating the cardiovascular outcomes of the habitual users of the drug or of new users compared with patients with the same disease who had never used methotrexate. The outcome of interest was the overall pooled odds ratio (OR) of major adverse cardiovascular events, i.e., a composite of new- onset angina, acute coronary syndrome, need for percutaneous or surgical coronary revascularization, stroke, and cardiovascular death. The study was performed according to the PRISMA statement. RESULTS Seven observational studies, mostly engaging patients with RA, were included in the meta-analysis. The pooled odds ratio (OR) was 0.73 (95% CI=0.70- 0.77 p<0.001). When stratified meta-analysis models were assessed, the pooled OR was 0.80 (95% CI=0.66-0.97; p=0.022) for studies adjusting for clinical severity of RA. Furthermore, the OR was even more significant after adjustment for concomitant use of other drugs specific for RA (OR=0.71, 95% CI=0.67-0.75, p<0.001). CONCLUSION Methotrexate at low doses, such those used for maintenance therapy of RA, predicted a decreased risk of CVE. Since methotrexate doesn't interfere with blood lipids, platelet aggregation or insulin resistance, the protective association may originate from mechanisms other than those exerted by antiplatelet drugs or statins.