Prevalence of left internal mammary artery disease in patients undergoing coronary angiography for suspected coronary artery disease: A meta-analysis and meta-regression study

Left internal mammary artery (LIMA) to bypass left anterior descending artery has demonstrated to improve survival in multivessel coronary artery disease, but its routine angiography during index coronary angiography is seldom performed as LIMA is rarely diseased.

A systematic literature review and meta-analysis was conducted using PubMed and Cochrane databases selecting the studies reporting prevalence of LIMA disease among patients undergoing coronary angiography and considered for CABG. Meta-regression analysis was performed to evaluate the prevalence of LIMA disease and the relative predictive value of canonical risk factors. After scrimmage, 9 studies for a total of 1365 patients were included.

LIMA disease prevalence was 1.8 % (95 % CI; 1.2 %-2.8 %) in the entire cohort, whereas we reported a rate of subclavian artery disease of 7.6 % (95 % CI, 6–9.9 %). At univariate meta-regression analysis, only age (p = 0.031) and smoking habit (p = 0.035) were directly correlated with LIMA disease.

In conclusion, LIMA angiographic assessment might be considered in selected patients that could undergo CABG, during index coronary angiography. However, prospective studies are needed to better evaluate the safety of routine selective LIMA angiography prior to CABG and whether the practice is associated with improved clinical outcomes among those individuals.