Risk of Coronary Artery Disease in Patients with Polymyalgia Rheumatica: A Systematic Review and Meta-analysis

Background/Purpose: Several chronic inflammatory disorders, such as rheumatoid arthritis and systemic lupus erythematosus, are associated with an increased risk of coronary artery disease (CAD) as a result of accelerated atherosclerosis.  However, the data on polymyalgia rheumatica (PMR), one of the most common chronic inflammatory disorders in older adults, remain unclear due to limited number of epidemiological studies.  To further investigate this possible association, this systematic review and meta-analysis of observational studies was conducted to compare the risk of CAD in patients with PMR versus participants without it.

Methods: Two investigators independently searched published studies indexed in MEDLINE, EMBASE and the Cochrane database from inception to March 2016 using the terms “polymyalgia rheumatica” combined with the terms for coronary artery disease.  A manual search of references of selected retrieved articles was also performed.  The inclusion criteria were: (1). observational studies published as original studies to evaluate the risk of CAD among patients with PMR; (2). published odds ratios (OR), relative risk (RR) or hazard ratio (HR) or standardized incidence ratio (SIR) with 95% confidence intervals (CI) in the studies.  Study eligibility was independently determined by the two investigators noted above. The quality of each study was assessed using Newcastle-Ottawa scale. RevMan 5.3 software was used for data analysis.  Point estimates and standard errors were extracted from individual studies and were combined by the generic inverse variance method of DerSimonian and Laird.  Given the high likelihood of between-study variance, random-effect model rather than fixed-effect model was used.  Statistical heterogeneity was assessed using the Cochran’s Q test and I². 

Results: Out of 176 potentially relevant articles, four studies (three retrospective cohort studies and one cross-sectional study) with 34,569 patients with PMR were identified and included in this meta-analysis.  The pooled risk ratio of CAD in patients with PMR was 1.72 (95% CI, 1.21 to 2.45). The statistical heterogeneity of this meta-analysis was high with an I² of 97%.

Conclusion: The risk of CAD among patients with PMR is 70% higher than in patients without PMR.  This finding has importance for the assessment and management of cardiovascular disease in these patients.