Short- and long-term cardiovascular outcomes in insulin-treated versus non-insulin-treated diabetes mellitus patients after percutaneous coronary intervention: A systematic review and meta-analysis.

Aims: This study aims to assess differences in severity of short-term (<1 year) and long-term (≥1 year) adverse CV outcomes after PCI in insulin-treated vs. non-insulin-treated diabetes mellitus (DM) patients.

Methods: A systematic search on Pubmed and Embase led to the incorporation of 29 studies that compared post-percutaneous coronary interventional outcomes in insulin-treated and non-insulin-treated diabetes mellitus. Diabetes mellitus (type 2) was defined as fasting blood glucose (FBG) level of >7.0 mmol/L or with an oral glucose tolerance test (OGTT) level of >11.1 mmol/L at least on two separate occasions. Adverse CV outcomes were assessed in insulin-treated and non-insulin-treated DM after the PCI procedure considered for the analyses were mortality, MACE, TLR, TVR, MI, stent thrombosis, target lesion failure (TLF), and need for-post PCI CABG. Data were pooled and analyzed using Review Manager 5.3, and risk ratios (RR) with respective 95% confidence intervals (CI) were calculated.The statistical analyses were carried out by Review Manager v.5.3, and the data were pooled using a random-effects model. Risk ratios (RRs) with 95% confidence intervals (CI) were reported along with forest plots. The chi-square test was performed to assess for differences between the subgroups. Heterogeneity across studies was evaluated using Higgins I statistics. Visual inspection of the funnel plot and Begg's regression test were used to assess publication bias.

Results: A total of 40,527 patients (11742 in the Insulin-treated diabetes mellitus group and 28785 in the non-insulin-treated DM group) who underwent PCI were included. The pooled analysis of short-term follow up outcomes preceding PCI demonstrated a significantly higher risk of mortality (RR = 1.75 [1.24,2.47]; p = 0.002), MI (RR = 1.81[1.14,2.87]; p = 0.01], stent thrombosis (RR = 1.63[1.13, 2.35]; p = 0.009) and target lesion revascularization (TLR) (RR = 1.29[1.02,1.63]; p = 0.03) in insulin-treated DM patients. Similarly, analysis of long-term follow-up studies depicted a significantly higher risk mortality (RR = 1.55 [1.22, 1.97]; p = 0.0003), MI (RR = 1.63 [1.35, 1.97]; p=<0.00001), MACE (R = 1.47 [1.31, 1.65]; p=<0.00001), stent thrombosis (RR = 1.54 [1.19,1.99]; p = 0.001), TLR (RR = 1.40 [1.18, 1.66]; p = 0.0001), target vessel revascularization (TVR) (RR = 1.35 [1.11, 1.64]; p = 0.003) in insulin-treated DM group after PCI versus non-insulin-treated DM patients.

Conclusion: Despite a tremendous technical success rate of multi-vessel stenting, people living with diabetes who were being treated with insulin had higher long-term, and short-term mortality rates, MI, TLR, TVR, and stroke compared to people living with diabetes who were being treated with means other than insulin and are more prone to detrimental cardiovascular outcomes.