Association of Elevated Plasma Homocysteine Level with Restenosis and Clinical Outcomes After Percutaneous Coronary Interventions: a Systemic Review and Meta-analysis.

PURPOSE: We conducted this systemic review and meta-analysis to investigate the association between elevated plasma homocysteine (Hcy) levels and recurrent restenosis and clinical outcomes after percutaneous coronary intervention (PCI). METHODS: PubMed, EMBASE, and Web of Science were systematically searched prior to May 2018. Studies evaluating the association between plasma Hcy levels and the occurrence of restenosis, major adverse cardiac events (MACE), all-cause mortality, cardiac death, non-fatal myocardial infarction (MI), and target lesion revascularization were identified. RESULTS: A total of 19 articles with 4340 participants were identified. Higher Hcy levels were not associated with an increased risk of restenosis (relative risk (RR) = 1.10, 95% CI 0.90-1.33). Hcy levels in the restenosis group were not significantly higher than in the non-restenosis group (weighted mean difference = 0.70, 95% CI - 0.23-1.63). Subgroup analysis revealed that higher Hcy levels were not associated with restenosis after stenting but appeared to increase the risk of restenosis after angioplasty. Elevated Hcy levels increased the risk of all-cause mortality by an average of 3.19-fold (RR = 3.19, 95% CI 1.90-5.34, P = 0.000), the risk of MACE by 1.51-fold (RR = 1.51, 95% CI 1.23-1.85, P = 0.000), and the risk of cardiac death by 2.76-fold (RR = 2.76, 95% CI 1.44-5.32, P = 0.000) but appeared not to increase the risk of non-fatal MI (RR = 1.36, 95% CI 0.89-2.09). CONCLUSIONS: Our meta-analysis suggests that although there is no clear association between higher Hcy levels and restenosis following stent implantation, higher Hcy levels appeared to increase the risk of restenosis after coronary angioplasty and also increased the risk of all-cause mortality, MACE, and cardiac death after PCI. REGISTRATION DETAILS: The protocol of this meta-analysis was registered on PROSPERO (CRD42018096466). ( http://www.crd.york.ac.uk/PROSPERO/display_record.php?ID=CRD42018096466 ).