Background: In this study, we aimed to investigate the impact of prophylactic intracoronary adenosine administered during percutaneous coronary intervention (PCI) due to unstable angina pectoris on myonecrosis by measuring post-procedural levels of cardiac troponin I (cTnI) and creatine kinase-myocardial band (CK-MB).
Methods: A total of 122 patients with unstable angina undergoing PCI were included in this single-center, double-blind, randomized study. The patients were randomly allocated to adenosine and placebo groups. In the adenosine group, a single-dose of intracoronary adenosine (100 μg for the right coronary artery and 150 μg for the left coronary artery) was administered. Primary endpoint was post-PCI myonecrosis, which was defined as abnormal levels of periprocedural cTnI. Secondary endpoints were defined as elevated cTnI levels [5 × upper limit of normal (ULN)], abnormal CK-MB levels, angiographic coronary flow measured by Thrombolysis In Myocardial Infarction (TIMI) frame count (TFC), the cumulative incidence of in-hospital death and in-hospital urgent target vessel revascularization (TVR).
Results: Clinical and angiographic characteristics of both adenosine (61 patients, 61 ± 9 years) and placebo (61 patients, 59 ± 10 years) groups were similar (p > 0.05 for all). Post-procedural abnormal cTnI levels in the adenosine group were significantly lower than the placebo group (32 % vs. 55 %, p: 0.011). cTnI >5 × ULN (21 % vs. 31 %, p: 0.217) and abnormal CK-MB levels (11 % vs. 19 %, p: 0.263) were similar in both groups. Post-procedural TFCs in the adenosine group were significantly lower than the placebo group (24 ± 4 vs. 27 ± 5, p: 0.004). In-hospital events including death and urgent TVR were not observed in either group.
Conclusion: Intracoronary administration of single-dose adenosine in patients with unstable angina undergoing PCI is associated with decreased periprocedural myonecrosis and improved coronary blood flow.
Keywords: Adenosine; Myonecrosis; Percutaneous coronary intervention; Unstable angina.