Factors associated with the development of cardiac allograft vasculopathy--a systematic review of observational studies.

Cardiac allograft vasculopathy (CAV) is a significant factor impacting outcomes after heart transplant. We performed a systematic review of risk factors for the development of CAV. A search of electronic databases was performed. The eligibility criteria included cohort and case-control studies with more than 50 adult patients submitted to a heart transplant. The outcome should be CAV diagnosed by angiography and/or intravascular ultrasound (IVUS). Two reviewers performed study selection, data abstraction, and quality assessment. Of 2514 citations, 66 articles were included--46 had 200 participants or less; 61 were single-center; and 44 were retrospective cohorts. The most used definition of CAV using angiography was the detection of any degree of abnormality (21 studies of 58). In studies using IVUS, an intimal thickness ≥0.5 mm was the most used definition (five of eight studies). Quality assessment revealed an inadequate description of patient selection, attrition, and accounting of potential confounders. Donor age, recipient age, recipient gender, etiology of heart failure, ischemic time, human leukocyte antigen matching, cytomegalovirus, lipid profile, and rejection episodes were the most studied factors. Our review indicates that the current evidence is not consistent across different studies. The definite contribution of risk factors for the development of CAV is still to be determined.