Methods: The literature screening was performed at Pubmed, Ovid, and Sciencedirect databases without date limitation. Studies investigating the co-existing diseases were included. The results of trials were evaluated with random or fixed effect model according to the heterogeneity.

Results: A total of 5009 articles were attained after database searching. Thirty five articles were included to the metaanalysis including 131.158 patients who met inclusion criteria. The most possible preoperative risk factors for mediastinitis were atrial fibrillation, pulmonary disease, diabetes mellitus, renal disease, peripheral vascular disease and systemic hypertension (p<0.05). Pulmonary hypertension, malignancy, hepatic and neurological diseases, heart failure and dyslipidemia were not found to be risk factors (p>0.05). Heterogeneity was not observed for four (renal, hepatic, neurological and peripheral vascular diseases) of 12 factors (I2<25%).

Conclusion: The results of our meta-analysis showed that preoperative co-existing diseases such as pulmonary hypertension, malignancy, heart failure, hepatic and neurological diseases, and dyslipidemia may not be risk factors for the development of mediastinitis following cardiac surgery.