Combined analysis of the safety of intra-coronary drug delivery during primary percutaneous coronary intervention for acute myocardial infarction: A study of three clinical trials.

Background: The local injection of novel cardioprotective study drugs prior to percutaneous coronary intervention could cause embolisation of thrombus, resulting in increased reperfusion injury and subsequent infarct size. The aim of this study was to assess the safety of the delivery of an intracoronary therapy delivered during primary percutaneous coronary intervention for acute myocardial infarction prior to the re-establishment of thrombolysis in myocardial infarction III flow.

Methods: One hundred sixty-seven patients with acute myocardial infarction successfully reperfused through primary percutaneous coronary intervention and undergoing Cardiac MRI within the first week after reperfusion were studied. Patients either underwent the delivery of an intracoronary agent (IMP or placebo) prior to balloon dilatation ( = 80) or standard primary percutaneous coronary intervention procedure ( = 117).

Results: Baseline characteristics were similar between the two groups. There were a similar number of successful procedures (IC IMP 75 (93.8%) vs. No IMP 114, (97.4%),  = 0.374), rates of no-reflow (IC IMP 1 (1.3%) vs. No IMP 2 (1.7%),  = 0.99) and levels of ST segment resolution (88.5% IC IMP vs. No IC IMP 87.0%,  = 0.669) between the two groups. Similar levels of microvascular obstruction were seen between the two groups with a trend to reduced infarct size, and improved ejection fractions in the IMP group. Lower MACE rates were seen in the IMP group.

Conclusion: The local intracoronary infusion of potential cardioprotective agents prior to the restoration of TIMI flow in patients undergoing primary percutaneous coronary intervention for acute myocardial infarction appears to be safe and does not increase microvascular damage. This route should be considered when testing novel cardioprotective agents.