Is progression of coronary artery calcification influenced by modality of renal replacement therapy? A systematic review

Background: Progression of coronary artery calcification is an important marker for cardiovascular morbidity in end-stage renal disease patients. Therefore, we reviewed the evidence on coronary artery calcification progression in different renal replacement therapies. Methods: MEDLINE (PubMed), Embase and TRIP databases were searched from 1999 - 2016. Additionally, bibliographies were searched by hand and citation tracking of key publications was performed. Prospective studies were included that examined coronary artery calcification with two or more multislice computed tomography scans >= 6 months apart in patients 18-75 years old receiving any renal replacement therapy, including kidney transplantation. Reporting of separate scores for different modalities was required. Two researchers extracted data independently with pilot-tested forms and assessed the risk of bias using a validated tool. Results: We identified 29 eligible studies that assessed coronary artery calcification progression in end-stage renal disease patients, of which 19 studies evaluated haemodialysis and 8 kidney transplantation. Evidence on progression in peritoneal dialysis (three studies) and nocturnal haemodialysis (one study) was limited. Meta-analysis was not possible due to diverse reporting methods of coronary artery calcification scores and definitions of progression. Median coronary artery calcification scores were considerably higher in haemodialysis cohorts at baseline, presumably due to a generally higher age and dialysis vintage. Median coronary artery calcification progressed universally. Visual inspection suggested the least progression in kidney transplant recipients. Conclusions: There is insufficient evidence to compare the influence of renal replacement therapies on coronary artery calcification progression. We advocate the adoption of a standardized reporting method of coronary artery calcification progression.