Impact of diabetes mellitus on myocardial perfusion after primary angioplasty in patients with acute myocardial infarction

OBJECTIVES: We investigated the impact of diabetes mellitus on myocardial perfusion after primary percutaneous coronary intervention (PCI) utilizing myocardial blush grade (MBG) and ST-segment elevation resolution (STR). BACKGROUND: Diabetes is an independent predictor of outcomes after primary PCI for acute myocardial infarction (AMI). Whether the poor prognosis is due to lower rates of myocardial reperfusion is unknown. METHODS: Reperfusion success in those with and without diabetes mellitus was determined by measuring MBG (n = 1,301) and STR analysis (n = 700) in two substudies of the Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications (CADILLAC) trial among patients undergoing primary PCI for AMI. RESULTS: There were no differences between those with or without diabetes with regard to postprocedural Thrombolysis In Myocardial Infarction (TIMI) flow grade 3 (>95%), distribution of infarct-related artery, and the frequency of stent deployment or abciximab administration. Patients with diabetes mellitus were more likely to have absent myocardial perfusion (MBG 0/1, 56.0% vs. 47.1%, p = 0.01) and absent STR (20.3% vs. 8.1%, p = 0.002). Diabetes mellitus (hazard ratio [HR] 1.63 [95% confidence interval (CI) 1.17 to 2.28], p = 0.004) was an independent predictor of absent myocardial perfusion (MBG 0/1) and absent STR (HR 2.94 [95% CI 1.64 to 5.37], p = 0.005) by multivariate modeling. CONCLUSIONS: Despite similar high rates of TIMI flow grade 3 after primary PCI in patients with and without diabetes, patients with diabetes are more likely to have abnormal myocardial perfusion as assessed by both incomplete STR and reduced MBG. Diminished microvascular perfusion in diabetics after primary PCI may contribute to adverse outcomes.