Impact of Diabetes Mellitus on Outcomes of Percutaneous Coronary Intervention in Chronic Total Occlusions: A Systematic Review and Meta-Analysis

Background: Patients with diabetes mellitus (DM) have a high prevalence of coronary chronic total occlusions (CTOs). We conducted a systematic review and meta-analysis to characterize outcomes after CTO percutaneous coronary intervention (PCI) in patients without or with DM. Methods: PubMed, EMBASE, Cochrane, and Google Scholar were queried for studies comparing non-DM vs. DM patients undergoing attempted CTO PCI. The primary outcome was all-cause mortality at longest follow-up (at least 6 months). Secondary outcomes were major adverse cardiovascular events (MACE) which is a composite endpoint including myocardial infarction, cardiac or all-cause mortality and any revascularization in patients after CTO PCI, target vessel revascularization (TVR), myocardial infarction (MI), Japanese chronic total occlusion (J-CTO) score and prevalence of multivessel (MV) CTO disease. We used a random effects model to calculate odds ratios (ORs) and 95% confidence intervals (CIs). Results: Sixteen studies, including 2 randomized control trials and 14 observational studies, met inclusion criteria. At longest follow-up, all-cause mortality (OR 0.54 [95% CI 0.37–0.80], p < 0.0001) and MACE (OR 0.82 [95% CI 0.72–0.93], p < 0.00001) were significantly lower in non-DM CTO patients. MV CTO disease was less prevalent in patients without DM (OR 0.80 [95% CI 0.69–0.93], p = 0.004). However, there were no differences in MI, TVR and J-CTO score. Conclusions: Non-diabetics undergoing CTO PCI have lower all-cause mortality and MACE than diabetics. Future research may determine if DM control improves diabetics' CTO PCI outcomes.