The slow-flow or no-reflow (SF/NR) phenomenon is a serious complication during primary percutaneous coronary intervention (PCI), significantly impacting patient prognosis. This prospective observational study aimed to identify independent predictors of SF/NR, assess related clinical outcomes, and evaluate pharmacologic strategies employed in its management. A total of 150 patients presenting with acute coronary syndrome (ACS) and undergoing primary PCI at Hayatabad Medical Complex were enrolled from July 2023 to July 2024.

The incidence of SF/NR was 34.7%. Multivariate analysis identified advanced age, male gender, diabetes mellitus, high thrombus burden, elevated high-sensitivity C-reactive protein (Hs-CRP), and reduced estimated glomerular filtration rate (eGFR) as independent predictors of SF/NR. Notably, patients experiencing SF/NR had a significantly higher frequency of major adverse cardiovascular events (MACE), including cardiac death (19.2% vs. 2.0%), recurrent myocardial infarction (15.4% vs. 3.1%), heart failure (23.1% vs. 5.1%), and target vessel revascularization (9.6% vs. 1.0%). 

Regarding pharmacological management, intracoronary adenosine and epinephrine demonstrated variable effectiveness, with improved coronary flow observed in 62.5% and 37.5% of cases, respectively. These findings highlight the complex pathophysiology of SF/NR and the need for optimized, individualized treatment strategies.

This study underscores the importance of early identification of at-risk individuals based on clinical and biochemical parameters. Addressing modifiable predictors and refining therapeutic interventions may lead to improved myocardial perfusion and better clinical outcomes in patients undergoing PCI.

Dr. Sami Ullah is a dedicated Interventional Cardiologist and Assistant Professor interventional cardiology at the Department of Cardiology, Hayatabad Medical Complex, Peshawar. He holds dual fellowships in Adult and Interventional Cardiology and actively participates in undergraduate, postgraduate, and fellowship training programs and supervising interventional cardiology fellows under the fellowship program of the College of Physician and Surgeons Pakistan. His research interests focus on coronary interventions and procedural complications. He is involved in continuous academic mentorship and clinical advancement in the field.