Predictors of nonoptimal coronary flow after primary percutaneous coronary intervention with stent implantation for acute myocardial infarction

Summary Background Predictors of suboptimal coronary flow in the infarct-related artery (IRA) after stent-based primary percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI) have not been fully investigated. Methods and results Using the AMI-Kyoto Multi-Center Risk Study database, we retrospectively compared clinical manifestations and in-hospital prognosis between AMI patients undergoing stent-based primary PCI with final Thrombolysis In Myocardial Infarction (TIMI) grade ≤2 in the IRA (nonoptimal group, n = 69) and those with final TIMI grade 3 (optimal group, n = 1200). The nonoptimal group had higher prevalence of Killip class ≥3 at admission, higher frequency of mechanical support devices during procedures, larger value of maximal creatine phosphokinase, and a significantly higher in-hospital mortality rate (27.5% for nonoptimal vs. 9.0% for optimal, P < 0.001), compared with the optimal group. On multivariate analysis, Killip class ≥3 at admission was the independent predictor of the final nonoptimal flow (odds ratio 2.33, 95% confidence intervals 1.27–4.26 P = 0.006), but TIMI 3 flow before primary PCI and elapsed time (symptom onset-to-admission time) < 24 h were not. Conclusions Killip class ≥3 at admission is an independent predictor of the final nonoptimal flow in AMI patients undergoing primary PCI with stent implantation.