Results:

A total of 121 women who met the clinical inclusion criteria between June 2007 and August 2010 were included in this analysis: 71 were ineligible because of ≥50% stenosis (n = 69), coronary dissection (n = 1), or excessive tortuosity (n = 1). Fifty women were fully eligible with <50% angiographic stenosis of all major vessels, of which eight patients did not undergo IVUS for logistical reasons. Forty-four patients underwent CMR, including 36 of the 42 patients who underwent IVUS; the remaining six patients declined CMR after initial consent. Mean age of the study population was 57 years; 46/50 (92%) presented with chest pain. Six (12%) had a history of prior MI. Median peak troponin was 1.60 ng/ml (interquartile range, 0.44–4.31); 88% of patients had peak troponin >5 times the upper limit of normal (0.04 ng/ml). Thirty-four patients (68%) had an abnormal electrocardiogram, including ST-segment elevation in 11 patients (22%), ST-segment depression in 7 (14%), left bundle branch block in 1 (2%), and T-wave inversion (≥2 contiguous leads) in 22 (44%). Median diameter stenosis of the worst lesion was 20% by angiography; 15 patients (30%) had normal angiograms. Plaque disruption was observed in 16/42 patients (38%) undergoing IVUS. There were abnormal myocardial CMR findings in 26/44 patients (59%) including late gadolinium enhancement (LGE) in 17 patients, and T2 signal hyperintensity indicating edema in nine additional patients. The most common LGE pattern was ischemic (transmural/subendocardial). Nonischemic LGE patterns (midmyocardial/subepicardial) were also observed. Although LGE was infrequent with plaque disruption, T2 signal hyperintensity was common with plaque disruption.