Introduction: The reduction of coronary blood flow without epicardial vessel obstruction is considered as no-reflow phenomenon and it is observed after reperfusion. The frequency of this event is 5% to 50% depending of the population and the diagnostic criteria, affecting cardiac prognosis. It has been associated with increased mortality within the first 30 days after coronary angioplasty (RR 2,1 p 0,038), and it is related to heart failure and arrhythmia, this is why it is very important to identify the factors associated with no-reflow phenomenon in order to identify which patients could be beneficiaries of preventive therapies. Methodology: Matched Case-Control Study verified by the doctor who evaluated the occurrence in order to assure there are no interobserver variations. With a 1:4 ratio (18:72), carried out to identify factors associated to the presence of no-reflow in patients who underwent angioplasty, between November 2010 and May 2014 at the San Rafael Clinic (Bogota, Colombia). Results: The no-reflow frequency of the phenomenon was at 2.89%. The acute ST-segment elevated myocardial infarction (STEMI) was the unique variable that showed a statistically significant association to this occurrence at a p value of 0,002, OR 8,7, IC 95% (2,0 – 36,7). Discussion: The no-reflow phenomenon characteristics in this population were similar to what was described by other research studies; being the STEMI a strong associated factor.
