Outcomes of percutaneous coronary intervention in patients with coronary chronic total occlusions with versus without type 2 diabetes mellitus: A systematic review and meta-analysis

BACKGROUND: Nowadays, due to advanced techniques and well-trained interventionists in catheter labs, new scientific research has shown percutaneous coronary intervention (PCI) to be a safe treatment procedure in patients with chronic total occlusion (CTO). However, no study has systematically compared PCI outcomes in CTO patients with versus without type 2 diabetes mellitus (T2DM). Therefore, through this meta-analysis we aimed to systematically solve this issue. METHODS: Between September 2016 and June 2017, the Cochrane Database of Randomized Trials, EMBASE, and MEDLINE databases were carefully searched for publications comparing PCI outcomes in CTO patients with versus without T2DM. Long-term (≥1 year) adverse clinical outcomes were considered the endpoints. Discontinuous data were analyzed by RevMan 5.3 whereby odds ratios (OR) and 95% confidence intervals (CIs) were the statistical parameters. RESULTS: This analysis consisted of 1 randomized trial and 6 observational studies with a total number of 4571 patients with CTO (1915 patients with T2DM and 2656 patients without T2DM). Patients’ enrollment was between the years 1998 and 2015. During this long-term follow-up (≥1 year), mortality was significantly higher in CTO patients with T2DM (OR: 1.56, 95% CI: 1.05–2.31; P = .03, I(2) = 0%). Major adverse cardiac events (MACEs) and repeated revascularization were also significantly higher in patients with T2DM (OR: 1.30, 95% CI: 1.06–1.58; P = .01, I(2) = 10%) and (OR: 1.30, 95% CI: 1.06–1.59; P = .01, I(2) = 36%) respectively. However, myocardial infarction was not significantly different (OR: 1.01, 95% CI: 0.61–1.67; P = .96, I(2) = 26%). CONCLUSION: During this longer follow-up period post-PCI, mortality, MACEs and repeated revascularization in CTO patients with T2DM were significantly higher compared with similar patients without T2DM. Nevertheless, whether this hypothesis is relevant or not should be confirmed in larger trials.