Evaluation of the Clinical and Procedural Predictive Factors of no-Reflow Phenomenon Following Primary Percutaneous Coronary Intervention

Background: The no-reflow phenomenon is an uncommon and critical occurrence which myocardial reperfusion does not restore to its optimal level. Several predisposing factors of the no-reflow phenomenon have been identified. However, at present we know little about clinical predictors of no-reflow after percutaneous coronary intervention (PCI).

Objectives: In this study, we evaluated clinical predictors of no-reflow phenomenon after PCI in patients with acute STEMI, to plan a better treatment of these patients.

Patients and methods: During an 18-month period, from 2013 to 2014, 438 patients with acute myocardial infarction (AMI) presenting within the first 24 hours from symptoms onset were treated with primary PCI in the Rajaie Cardiovascular Medical and Research Center. Thrombolysis in myocardial infarction (TIMI) flow was measured in all patients on the first angiography, following stenting. A total of 49 patients were allocated to the case group, based on the no-reflow phenomenon occurred during primary PCI (TIMI grade 0 and 1) and 50 patients without the no-reflow phenomenon (TIMI grade ≥ 3) were randomly selected, as the control group. They were evaluated from the point of demographic variables and also infarction territory, pain duration, maximal ST-change, left ventricle (LV) function, laboratory data, coronary anatomy, culprit vessel, location of lesion, target vessel diameter, lesion length, eccentricity, thrombus grade, tortuosity, lesion angulation, bifurcation, predilation, postdilation, thrombus aspiration, number of stent, in stent thrombosis. Data were then analyzed with the SPSS statistical software.

Results: Mean age of patients was 59.47 (SD = 12.48) years, of which 75 (75.8%) were male and 24 (24.2%) were female. Based on univariable analysis, white blood cell (WBC) count, pain duration, LV function, maximal ST-change, thrombus grade and eccentricity were identified as predictors of the no-reflow phenomenon. After multivariable logistic regression: WBC count and thrombus grade remained the significant independent predictors of the no-reflow phenomenon (P < 0.05). In case group, slow-flow was seen in 42 (9.5%), while no-reflow was seen in seven (1.6%) patients.

Conclusions: The WBC count and thrombus grade are strong, independent predictive factors of developing the no-reflow phenomenon, in AMI patients undergoing primary PCI. There is also an association between the no-reflow phenomenon and pain duration, maximal ST-change, LV function, high sensitivity C-reactive protein (hs-CRP), bifurcation, eccentricity and coronary anatomy.