Impact of intracoronary adenosine on myonecrosis in patients with unstable angina pectoris undergoing percutaneous coronary intervention

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 mu g for the right coronary artery and 150 mu g 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 x 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 x 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.