Impact of intracoronary adenosine on the no-reflow phenomenon: A randomized, triple-blind, placebo-controlled clinical trial.

Introduction: The no-reflow phenomenon occurs in 5 % to 50 % of patients with ST-elevation myocardial infarction (STEMI) during primary percutaneous coronary intervention (PPCI), leading to suboptimal myocardial reperfusion and poor outcomes. Although intracoronary adenosine has shown benefits in studies, its use remains controversial. This analysis aims to evaluate the impact of intracoronary adenosine administration on preventing NRP during PPCI. Methods: In this randomized, triple-blind, placebo-controlled trial, 240 STEMI patients undergoing PPCI were divided into two cohorts, one receiving a bolus dose of intracoronary adenosine and the other receiving 5 cc of saline as a placebo before stenting. The primary endpoint was the incidence of NRP measured by Thrombolysis in Myocardial Infarction flow grade and frame count. Secondary endpoints included ST-segment resolution after 90 min, left ventricular ejection fraction, and major adverse cardiac events after 40 days. Results: Among 240 STEMI patients, adenosine did not significantly reduce angiographic no-reflow compared with placebo (TIMI flow grade ≤ 2: 15 % vs. 19.2 %, Conclusion: Prophylactic intracoronary adenosine did not significantly reduce angiographic no-reflow in STEMI patients undergoing primary PCI but was associated with greater left ventricular functional recovery at 40 days. These findings suggest a cardioprotective effect of adenosine on the microvasculature and myocardial tissue, supporting its potential role as an adjunctive therapy in STEMI management.