Abstract 12678: Microvascular Obstruction With Delayed Enhancement Cardiac Magnetic Resonance Predicts Severity of Myocardial Damage After Acute Myocardial Infarction

Abstract

Microvascular Obstruction With Delayed Enhancement Cardiac Magnetic Resonance Predicts Severity Of Myocardial Damage After Acute Myocardial Infarction

Background Some patients with acute myocardial infarction (MI) show severe myocardial damage even though reperfusion therapies are successfully and smoothly conducted. Cardiac magnetic resonance (CMR) imaging is a useful modality in assessing myocardial structural changes in patients with acute MI. The hypo-enhanced regions within the hyper-enhanced infarct areas detected by CMR imaging are considered to be areas of microvascular obstruction (MO). QRS score on electrocardiogram (ECG) can also reflect the severity of myocardial damage. We investigated whether MO on CMR imaging could be an important finding to determine the magnitude of myocardial damage in patients with acute MI in comparison with QRS score on ECG.

Methods 72 patients with first acute MI who underwent primary percutaneous coronary intervention (PCI) were enrolled. CMR imaging was performed 9.96 ± 5.10 days after PCI. QRS score was calculated by the Selvester and Wagner QRS scoring system 9±5.10 days after PCI. MO was defined by CMR imaging. Patients were divided into 2 groups as follows: MO group (n=41) and non-MO group (n=31).

Results The QRS score was significantly greater in the MO group than in the non-MO group (9.35±3.53 vs 4.80±3.16, p<0.001). There was no significant difference in time from onset to reperfusion between both groups (304.62±276.74 min vs 300.29±322.92 min, p=NS). The time from reperfusion to peak CPK was longer in the non-MO group than in the MO group (453.76±212.09 vs 327.68±128.40, p<0.001).

Conclusions MO after acute MI inversely correlated with the QRS score, indicating that MO reflects severe myocardial damage. CMR imaging is a useful modality in detecting irreversible myocardial damage early after acute MI.