234 A novel in vivo marker for ischemic tissue injury early after coronary occlusion

Background

Early identification of acute myocardial ischemia is a diagnostic challenge. We aimed at identifying the earliest time point at which T2-weighted cardiovascular magnetic resonance imaging could visually identify acute ischemia.

Methods

We studied seven dogs with serial T2-weighted and cine imaging at baseline, during and early after transient coronary occlusion (25–35 minutes) in a 1.5 T MRI system. Late gadolinium enhancement was used to assess irreversible injury.

Results

28 ± 4 minutes after experimental coronary artery occlusion, we observed a transmural area of high T2 signal intensity (contrast to noise ratio to remote myocardium 11.0 ± 10; p < 0.0001), matching areas with new onset regional wall motion abnormalities. Late enhancement imaging performed after reperfusion did not show irreversible injury in any of the dogs (Figure 1).

Figure 1

We aimed at identifying the earliest time point at which T2-weighted imaging visually identifies acute ischemia in a dog model(n = 7). T2 imaging detected ischemia 28 ± 4 minutes after coronary occlusion before the onset of irreversible damage as identified by late gadolinium enhancement.

Conclusion

We provide the first preliminary evidence that T2-weighted CMR imaging represents a novel in vivo marker for ischemic tissue injury likely before the onset of irreversible injury. T2-weighted CMR may offer a novel potential means of identifying acute ischemia in acute coronary syndromes.