Predictors of the No-Reflow Phenomenon in ST-Elevation Myocardial Infarction Patients Undergoing Primary Percutaneous Coronary Intervention: A Retrospective Study from Peshawar Institute of Cardiology

Abstract

Objectives: To identify clinical, procedural, and biochemical predictors of the no-reflow phenomenon in patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI) at the Peshawar Institute of Cardiology, Peshawar. Methodology: This retrospective, single-center study included 288 STEMI patients who underwent primary PCI between September 2023 and August 2024. Demographic, clinical, and angiographic data were collected from hospital records. The no-reflow phenomenon was defined as a Thrombolysis in Myocardial Infarction (TIMI) flow grade ≤2 and a myocardial blush grade <2 following PCI. Continuous variables were analyzed using Mann-Whitney U tests and categorical variables using chi-square tests. Multivariable logistic regression identified independent predictors of no-reflow, with p < 0.05 considered statistically significant. Results: Of the 288 patients, 60% were male with a mean age of 52.7 ± 19.6 years. The no-reflow phenomenon occurred in 25% of patients. Although the no-reflow group had lower left ventricular ejection fraction (35.8 ± 3.9%) and higher systemic immune-inflammatory index (2100 ± 200) compared to the reflow group (39.5 ± 4.3% and 1800 ± 250, respectively), these differences were not statistically significant (p > 0.05). However, the incidence of complications arrhythmias, heart failure, and cardiogenic shock was significantly higher in the no-reflow group (χ² = 12.45, p = 0.015). Conclusion: LVEF and systemic immune-inflammatory index were not found to be significant predictors of the no-reflow phenomenon. However, the strong association of no-reflow with major complications underscores the need for early recognition and management of high-risk patients to improve post-PCI outcomes.