Clinical Predictors And Prognosis Of Refractory Thrombus In STEMI Patients

BackgroundAcute ST-segment elevation myocardial infarction（STEMI）is currently one of the major causes of cardiovascular mortality and morbidity.Primary percutaneous coronary intervention（p PCI）is highly effective in restoring a normal Thrombolysis In Myocardial Infarction（TIMI）flow in patients with STEMI,which can save the ischemic myocardium,and improve the clinical outcome.Coronary thrombosis is unequivocally the most important pathophysiological process underlying STEMI.The amount of intra coronary thrombosis may vary among different STEMI patients.The high thrombus burden of the infarct-related artery（IRA）is related to stent thrombosis,distal embolism,no-reflow phenomenon,and long-term mortality.Current guidelines do not recommend routine TA for STEMI patients during p PCI,but for patients with high thrombus burden,TA may be an effective measure to reduce distal embolism and improve microvascular perfusion.However,TA is not always effective,the exsiting of residual thrombus causes worse microvascular dysfunction and myocardial damage.MethodsA total of 1305 consecutive patients with STEMI who underwent primary percutaneous coronary intervention（p PCI）were screened.The refractory thrombus group（n=15）was defined as infarct-related artery TIMI（thrombolysis in myocardial infarction）flow < grade 2 after multiple thrombus aspiration.The control group（n=45）was age-and sex-matched and was selected form the same batch of patients.Baseline hematologic indices were measured before the p PCI.The major adverse cardiovascular events（MACE）were recorded during follow-up.ResultsThe refractory thrombus group had significantly higher red cell distribution width（RDW）at baseline compared with the control group（13.1 [12.4-13.7] vs 12.6 [12.3- 12.8],P = 0.008）.In multivariate logistic regression analysis,RDW was an independent predictor of refractory thrombus（odds ratio:7.937,P = 0.021）.The area under the receiver-operating characteristic curve of the RDW was 0.730（95%CI: 0.548-0.912,P = 0.008）.During a mean period of 26 months follow-up,patients in the refractory thrombus group tended to be higher percent MACEs compared with patients in the control group（53.3% vs 6.7%,P<0.001）.ConclusionIn the present study,we found that the refractory thrombus in STEMI patients was associated with the worse prognosis and the increased RDW might be a potential independent predictor.