Determination of the Prevalence and Prognostic Importance of Unrecognized Non-Q-wave Myocardial Infarction by MRI

Unrecognized Non-Q-wave Myocardial Infarction: Prevalence, Angiographic Correlation, and Prognostic Significance in Patients With Suspected Coronary Disease

The first aim of this study is to determine how often unrecognized myocardial infarction occur in patients using a magnetic resonance imaging (MRI) technique (known as delayed enhancement MRI), as compared to the electrocardiogram. The second aim of this study is to determine the severity of coronary heart disease of the patients with unrecognized myocardial infarction. The final aim is to determine how the presence of unrecognized myocardial infarction detected by the MRI affects lifespan.

Unrecognized myocardial infarction (MI) is known to constitute a substantial portion of lethal coronary heart disease. However, since the diagnosis of unrecognized MI is based on the appearance of incidental Q-waves on 12-lead electrocardiography, the syndrome of unrecognized non-Q-wave MI has not been described. Delayed-enhancement cardiovascular magnetic resonance (DE-CMR) can accurately identify non-Q-wave MI. The aims of this study are three-fold: 1. to determine the prevalence of unrecognized non-Q-wave and Q-wave MI, 2. to define predictors of unrecognized non-Q-wave MI, 3. to determine the prognostic significance of unrecognized non-Q-wave MI.

Inclusion Criteria:

• Patients with suspected coronary artery disease referred for invasive coronary angiography

Exclusion Criteria:

• Clinical history of myocardial infarction
• Percutaneous coronary intervention
• Coronary artery bypass surgery
• Known uncured malignancy
• History of hypertrophic cardiomyopathy, myocarditis, or infiltrative heart disease
• Contraindication of magnetic resonance imaging