Background: Neutrophils and reactive oxygen species (ROS) are suggested to be involved in irreversible myocardial reperfusion injury and stunning. We investigated the relations between circulating biochemical markers and myocardium at risk (MaR), myocardial infarct (MI) size, salvage, and recovery of function in man.
Methods and results: In patients undergoing PCI serial blood samples were acquired for markers of inflammatory response (myeloperoxidase [MPO], neutrophil-gelatinase-associated lipocalin [NGAL], interleukins 6 and 8 [IL-6/8], tumor necrosis factor-a [TNF-a], high-sensitive C-reactive protein [hsCRP]), matrix remodeling (matrixmetalloproteinase-9 [MMP-9]) and ROS (malondialdehyde [MDA], isoprostane [IsoP]). Samples were obtained before PCI and 1.5, 3, and 24 hours after reperfusion. Myocardial perfusion SPECT (MPS) was used to assess MaR. Late gadolinum-enhanced cardiac magnetic resonance imaging was performed for regional function in the acute setting, at 1 week and 6 months, and at 1 week also for MI size. Sixteen patients (15 men; 42-78 years) were enrolled, 12 of whom underwent MPS. Peak and cumulative NGAL and cumulative MMP-9 showed inverse correlations to MaR. No correlation was found for MI size. Peak MPO correlated inversely to salvage and to recovery of regional function in the infarcted segments at 1 week and 6 months.
Conclusions: This is the first study in man to show inverse relations between circulating NGAL and MMP-9 and MaR. The current results do not support that ROS has a role in stunning in man. MI size showed no significant correlation to any parameter, challenging inflammatory treatment in reperfusion.