Impact of Duration of Diabetes Mellitus on Long-Term Outcome in Type 2 Diabetic Patients with Primary Percutaneous Coronary Intervention after the First Myocardial Infarction

<b><i>Background:</i></b> Diabetes mellitus (DM) increases the risk of mortality in patients with acute myocardial infarction (AMI). The impact of the diabetes duration on the long-term outcome of those with percutaneous coronary intervention (PCI) after the first AMI is unclear. In this study, we evaluated the predictive value of diabetes duration in the occurrence of major adverse cardiovascular and cerebrovascular events (MACCEs). <b><i>Methods:</i></b> A total of 394 type 2 DM patients with PCI after the first AMI were enrolled and were divided into two groups by the diabetes duration: a short-DM group with diabetes duration of &lt;5 years and a long-DM group with a duration of ≥5 years. The clinical endpoint was MACCEs. <b><i>Results:</i></b> Multivariate Cox regression analysis found that the diabetes duration was independently associated with increased occurrence of MACCEs (HR: 1.512, 95% CI: 1.033, 2.215, <i>p</i> = 0.034), along with hypertension, Killip class III or IV, creatinine, multivessel disease, and continuous hypoglycemic therapy. After adjusting for the confounding variables, a nested Cox model showed that diabetes duration was still an independent risk factor of MACCEs (HR: 1.963, 95% CI: 1.376, 2.801, <i>p</i> &lt; 0.001). The Kaplan-Meier survival curve illustrated a significantly high risk of MACCEs (HR: 2.045, <i>p</i> &lt; 0.0001) in long-duration DM patients. After propensity score matching, a longer diabetes duration was associated with an increased risk of MACCE occurrence. <b><i>Conclusion:</i></b> Long-duration diabetes was independently associated with poor clinical outcomes after PCI in patients with their first myocardial infarction. Despite the diabetes duration, continuous hypoglycemic therapy significantly improved long-term clinical outcomes.