Distal coronary embolization following acute myocardial infarction increases early infarct size and late left ventricular wall thinning in a porcine model

Abstract

BackgroundDistal coronary embolization (DCE) of thrombotic material occurs frequently during percutaneous interventions for acute myocardial infarction and can alter coronary flow grades. The significance of DCE on infarct size and myocardial function remains unsettled. The aims of this study were to evaluate the effects of DCE sufficient to cause no-reflow on infarct size, cardiac function and ventricular remodeling in a porcine acute myocardial infarction model.Methods and resultsFemale Yorkshire pigs underwent 60 min balloon occlusion of the left anterior descending coronary artery followed by reperfusion and injection of either microthrombi (prepared from autologous porcine blood) sufficient to cause no-reflow (DCE), or saline (control). Animals were sacrificed at 3 h (n = 5), 3 days (n = 20) or 6 weeks (n = 20) post-AMI. Cardiovascular magnetic resonance (CMR), serum troponin-I, and cardiac gelatinase (MMP) and survival kinase (Akt) activities were assessed. At 3d, DCE increased infarct size (CMR: 18.8 % vs. 14.5 %, p = 0.04; serum troponin-I: 13.3 vs. 6.9 ng/uL, p < 0.05) and MMP-2 activity levels (0.81 vs. 0.49, p = 0.002), with reduced activation of Akt (0.06 versus 0.26, p = 0.02). At 6 weeks, there were no differences in infarct size, ventricular volume or ejection fraction between the two groups, although infarct transmurality (70 % vs. 57 %, p< 0.04) and ventricular thinning (percent change in mid anteroseptal wall thickness:-25.6 % vs. 0.7 %, p = 0.03) were significantly increased in the DCE group.ConclusionsDCE increased early infarct size, but without affecting later infarct size, cardiac function or ventricular volumes. The significance of the later remodelling changes (ventricular thinning and transmurality) following DCE, possibly due to changes in MMP-2 activity and Akt activation, merits further study.

Pyrrolidine Dithiocarbamate Attenuates Cardiocyte Apoptosis and Ameliorates Heart Failure Following Coronary Microembolization in Rats

“…It can lead to low or no-reflow during myocardial perfusion, resulting in myocardial infarction and infarct production, coronary reserve reduction, arrhythmias, and contractile dysfunction (16,17,18). Studies have documented that serious coronary microembolization can induce chronic HF (19,20).…”

Hemorrhage promotes chronic adverse remodeling in acute myocardial infarction: a T1, T2 and BOLD study

“…3 Importantly, I/R is responsible for the angiographic "no-reflow" phenomenon that arises from vascular injury, distal embolization, platelet aggregation etc, manifesting as microvascular obstruction (MVO) when imaged with contrast-enhanced cardiovascular magnetic resonance (CMR). [4][5][6][7] MVO has been correlated with poor patient outcome, occurring in 50% of ST-segment elevation myocardial infarction (STEMI) patients. [8][9][10][11] Beyond MVO, reperfusion hemorrhage (HEM) has now been confirmed to be an independent predictor of adverse cardiovascular outcomes 8,9,12,13 with predictive power greater than MVO in terms of adverse remodeling and health outcomes.…”

“…Enhanced intracellular and interstitial edema is a consistent feature of I/R arising from the body's inflammatory response 3 . Importantly, I/R is responsible for the angiographic “no‐reflow” phenomenon that arises from vascular injury, distal embolization, platelet aggregation etc, manifesting as microvascular obstruction (MVO) when imaged with contrast‐enhanced cardiovascular magnetic resonance (CMR) 4–7 . MVO has been correlated with poor patient outcome, occurring in 50% of ST‐segment elevation myocardial infarction (STEMI) patients 8–11 …”

Multiparametric CMR imaging of infarct remodeling in a percutaneous reperfused Yucatan mini‐pig model

“…Swine are commonly used for large animal models in cardiovascular research due to their similarities in heart size and coronary anatomy to the human . Many ischemia reperfusion porcine models, including Yorkshire and Göttingen pigs, have been well characterized with cardiac magnetic resonance (CMR) . Each animal model has its own specific advantages.…”