Association of Left Anterior Descending Culprit Vessel with Angiographic No-Reflow during Primary Percutaneous Coronary Intervention for ST-Segment Elevation Myocardial Infarction: A Prospective Comparative Study

Abstract

Objectives: To compare the frequency of angiographic no-reflow (NR) between left anterior descending (LAD) and non-left anterior descending (non-LAD) infarct-related arteries in patients undergoing primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI). Methodology: This prospective observational comparative study was conducted between September 2025 and February 2026. A total of 192 consecutive STEMI patients undergoing primary PCI were enrolled and categorized according to the angiographically identified infarct-related artery into LAD (n=96) and non-LAD (n=96) groups. Demographic, clinical, angiographic, and procedural characteristics were recorded using a structured proforma. Angiographic no-reflow was defined as final thrombolysis in myocardial infarction (TIMI) flow grade 0–2 after successful mechanical opening of the culprit vessel in the absence of residual stenosis, dissection, visible thrombus, or coronary spasm. Comparative analyses were performed using appropriate univariate tests. Results: Among the 192 participants, the mean age was 51.3±7.4 years and 76.0% were male. Patients with LAD-related STEMI were significantly older and more frequently diabetic than those with non-LAD infarctions. Overall, angiographic no-reflow occurred in 54 (28.1%) patients. The frequency of no-reflow was significantly higher in the LAD group compared with the non-LAD group (36.5% versus 19.8%, p=0.010). After adjustment for age, diabetes mellitus, time to presentation, baseline TIMI flow, thrombus burden, lesion morphology, stent length, and stent diameter, LAD involvement remained independently associated with no-reflow (adjusted odds ratio 2.0; 95% confidence interval 1.0–4.1; p=0.047). Delayed presentation, high thrombus burden, and longer stent length were also independently associated with no-reflow. Conclusion: LAD-related STEMI was associated with a significantly higher frequency of angiographic no-reflow compared with non-LAD culprit vessel STEMI during primary PCI. The association persisted after adjustment for important clinical and procedural variables.