Abstract Body (Do not enter title and authors here): Background: Adults with congenital heart disease (ACHD) are lifelong at high risk for premature cardiovascular events and life-threatening complications, suggestive of early or accelerated cardiovascular disease. Endothelial and microvascular dysfunction as well as arterial stiffness play a key role in the emergence and progression of cardiovascular complications. As vascular dysfunction may precede the occurrence of adverse events, early identification of endothelial damage markers in ACHD is crucial.
Aim: This is the first systematic review and meta-analysis of studies investigating the endothelial and microvascular function in ACHD patients versus healthy controls.
Methods: We systematically searched four major electronic databases (PubMed, CENTRAL, Scopus, Web of Science), ClinicalTrials.gov and grey literature. We included studies evaluating endothelial and microvascular function with any semi- or non-invasive method in adult patients with and without ACHD. Studies exploring arterial stiffness indices were also investigated.
Results: In total, 31 studies (1118 ACHD patients, 794 controls) were included in this systematic review. Branchial arterial endothelium-dependent (assessed via flow-mediated dilatation, FMD) and -independent vasodilation (assessed via nitroglycerine-mediated dilatation, NMD) were impaired in ACHD patients versus controls (mean difference [MD] -2.5, 95% confidence intervals [CI] -3.7; -1.3 and MD -3.9, 95%CI -6.8; -1.0, respectively). Microvascular dysfunction was also evident; significantly lower reactive hyperemia index and peripheral arterial tonometry (PAT) ratio were found in ACHD patients compared with controls (MD −0.26, 95%CI −0.48; −0.04 and MD −0.26, 95%CI −0.5; −0.4, respectively). Regarding arterial stiffness, pooled analysis revealed non-significant differences in pulse wave velocity between the study groups (standardized MD 0.2, 95%CI -0.2; 0.6). However, augmentation index was significantly higher in ACHD (standardized MD 1.6, 95%CI 0.8; 2.4).
Conclusions: ACHD patients have impaired endothelial and microvascular function and increased arterial stiffness, factors that may be responsible for the increased adverse cardiovascular events in this population.