Clinical and Angiographic Factors Associated with the No-Reflow Phenomenon Following Primary Percutaneous Coronary Intervention in Patients with ST-Segment Elevation Myocardial Infarction

Abstract

Objectives: To determine the frequency of the no-reflow (NRF) phenomenon and identify clinical and angiographic factors associated with its occurrence among patients undergoing primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI). Methodology: This analytical cross-sectional study was conducted at the Department of Cardiology, Bahawal Victoria Hospital, Bahawalpur, Pakistan, from March to December 2025. Patients aged 20–60 years presenting with STEMI and undergoing primary PCI with stent implantation were consecutively enrolled. The primary outcome was angiographic NRF, defined as a post-procedural Thrombolysis in Myocardial Infarction (TIMI) flow grade of 0–2 following stent deployment. Results: A total of 80 patients were included in the analysis. The mean age was 52.4±7.1 years, and 61 (76.3%) participants were male. NRF occurred in 23 patients, yielding a frequency of 28.8%. On multivariable logistic regression analysis, diabetes mellitus (aOR: 2.7; 95% CI: 1.0–7.4; p=0.047), renal insufficiency (aOR: 4.4; 95% CI: 1.0–18.7; p=0.032), baseline left ventricular ejection fraction (LVEF) <35% (aOR: 3.6; 95% CI: 1.2–10.8; p=0.024), and initial TIMI flow grade 0–1 (aOR: 3.1; 95% CI: 1.0–9.6; p=0.048) were independently associated with NRF. Multivessel coronary artery disease and longer stent length demonstrated associations on univariable analysis but did not remain statistically significant after adjustment. Conclusion: The no-reflow phenomenon was observed in nearly one-third of patients undergoing primary PCI for STEMI. Diabetes mellitus, renal insufficiency, reduced baseline LVEF, and poor pre-procedural TIMI flow were independently associated with NRF. Early identification of these high-risk characteristics may facilitate risk stratification and procedural planning; however, the findings should be interpreted cautiously due to the observational design and limited number of outcome events.