Peripheral Arterial Disease in Patients with Giant Cell Arteritis: A Systematic Review and Meta-analysis

Background/Purpose: Several chronic inflammatory disorders, such as rheumatoid arthritis and systemic lupus erythematosus, have been shown to increase cardiovascular disease risk secondary to accelerated atherosclerosis.  Similarly, there are data to suggest that patients with giant cell arteritis (GCA), another common chronic inflammatory condition, have an increased risk of coronary artery disease.  However, the data on peripheral arterial disease (PAD) remain unclear due to conflicting epidemiological studies.  Thus, to further investigate this association, we conducted a systematic review and meta-analysis of observational studies that compared the risk of PAD in patients with GCA versus participants without it.

Methods: Two investigators (P.U. and P.C.) independently searched published studies indexed in MEDLINE, EMBASE and the Cochrane database from inception to March 2014 using the terms “giant cell arteritis” and “temporal arteritis” combined with the terms “peripheral artery disease”, “peripheral vascular disease” and “arterial occlusive disease”  A manual search of references of retrieved articles was also performed.  The inclusion criteria were as follows: (1) observational studies published as original studies to evaluate the association between GCA and clinically relevant PAD and (2) odds ratios (OR’s), relative risk (RR’s) or hazard ratio (HR’s) or standardized incidence ratio (SIR’s) with 95% confidence intervals (CI’s) were provided.  Study eligibility was independently determined by the two investigators noted above.  The quality of each study was, again, independently assessed by the two investigators using Newcastle-Ottawa scale.

RevMan 5.2 software was used for the 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, we used a random-effect model rather than a fixed-effect model.  Statistical heterogeneity was assessed using the Cochran’s Q test. 

Results: Out of 460 potentially relevant articles, four studies (three retrospective cohort studies and one case-control study) were identified and included in our data analysis.  The pooled risk ratio of PAD in patients with GCA was 1.77 (95% CI, 1.01 to 3.12). The statistical heterogeneity of this meta-analysis was high with an I² of 89%.

Conclusion: Our study demonstrated a statistically significant increased PAD risk among patients with GCA.