Short-Term Versus Long-Term Adverse Cardiovascular Outcomes Post Percutaneous Coronary Intervention in Patients with Insulin-Treated Type 2 Diabetes Mellitus: A Simple Meta-Analysis

INTRODUCTION: Type 2 diabetes mellitus (T2DM) is a major health issue, especially in patients with coexisting coronary artery disease (CAD). Patients with insulin-treated T2DM (ITDM) have worse outcomes than those with non-insulin-treated T2DM. Very few studies have compared short-term to long-term adverse cardiovascular outcomes following percutaneous coronary intervention (PCI) in patients on insulin therapy. Therefore, in this meta-analysis, we systematically compared short-term to long-term adverse cardiovascular outcomes in a population of patients with ITDM following PCI. METHODS: We searched for English-language publications focusing on PCI in patients with ITDM using specific search terms/phrases. All the participants accepted for inclusion in this meta-analysis were treated with a drug-eluting stent. Post-intervention adverse cardiovascular outcomes observed during short-term and long-term follow-up periods were assessed and compared. Statistical analysis was carried out using the popular RevMan 5.3 software. Odd ratios (OR) with 95% confidence intervals (CI) were calculated. RESULTS: Six studies comprising 1568 participants with ITDM in total were included in this simple meta-analysis. Patient enrollment periods varied but enrollment occurred during the years 1993–2012. When a fixed-effects statistical model was used, post-PCI adverse cardiovascular outcomes—such as major adverse cardiac events (MACEs) (OR 3.33, 95% CI 2.64–4.21; P = 0.00001), all-cause mortality (OR 5.73, 95% CI 3.37–9.73; P = 0.00001), myocardial infarction (MI) (OR 1.47, 95% CI 1.05–2.07; P = 0.02), and repeated revascularization (OR 4.78, 95% CI 3.29–6.94; P = 0.00001)—were found to be significantly more likely during the long-term follow-up period. A similar result was observed with a random-effects statistical model. CONCLUSION: Adverse cardiovascular outcomes post PCI were significantly more likely during the long-term follow-up period than during the short-term follow-up period in these patients with T2DM on insulin therapy. This hypothesis requires confirmation via new comparative trials that consider short-term and long-term follow-up periods.