Adenosine improves post-procedural coronary flow but not clinical outcomes in patients with acute coronary syndrome: A meta-analysis of randomized trials

AIMS: Adjunctive therapy with adenosine has been shown to improve coronary flow in patients with acute coronary syndromes (ACS); it is unclear, however, whether adenosine can effectively reduce adverse clinical events. The aim of our study was to perform a meta-analysis of all randomized controlled trials (RCTs) investigating angiographic and clinical outcomes in ACS patients undergoing PCI or thrombolysis and receiving adjunctive adenosine therapy vs. placebo. METHODS: Medline/CENTRAL/EMBASE and Google Scholar database were scanned. The meta-analysis included ten RCTs (N=3821). All-cause mortality was chosen as primary endpoint. Secondary endpoints were re-infarction (MI), heart failure (HF) symptoms (NYHA class III/IV), no-reflow (defined as TIMI 0 flow) and >50% ST-resolution. RESULTS: Adenosine compared to placebo was associated with a significant reduction of post-procedural no-reflow (OR [95% CI]=0.25 [0.08-0.73], p=0.01); however, at a median follow-up of 6 months, prior treatment with adenosine did not confer significant benefits in terms of reduction of mortality (OR(Fixed) [95% CI]=0.87 [0.69-1.09], p=0.23), as well as re-MI (p=0.80), HF symptoms (p=0.44) and ST-resolution (p=0.09). Separate analyses conducted in the subgroups of ST-elevation MI patients treated with either PCI or thrombolysis confirmed the findings found in the overall population. CONCLUSIONS: This meta-analysis shows that adenosine adjunctive therapy does not improve survival nor reduce the rates of re-MI and HF symptoms in patients with ACS treated with PCI or thrombolysis. The beneficial effect on post-procedural coronary flow was not associated with consistent advantages on clinical outcomes.