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Background There is no angiographically demonstrable obstructive coronary artery disease (CAD) in a significant minority of patients with myocardial infarction (MI), particularly women. We sought to determine mechanism(s) of MI in this setting using multiple imaging techniques. Methods and Results Women with MI were enrolled prospectively, prior to angiography if possible. Women with ≥50% angiographic stenosis or use of vasospastic agents were excluded. Intravascular ultrasound (IVUS) was performed during angiography and cardiac magnetic resonance imaging (CMR) within one week. Fifty women (age 57±13 years) had median peak troponin 1.60 ng/ml; 11 had ST elevation. 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%) undergoing CMR: late gadolinium enhancement (LGE) in 17 and T2 signal hyperintensity indicating edema in 9 additional patients. The most common LGE pattern was ischemic (transmural/subendocardial). Non-ischemic LGE patterns (midmyocardial/subepicardial) were also observed. LGE was infrequent with plaque disruption but T2 signal hyperintensity was common with plaque disruption. Conclusions Plaque rupture and ulceration are common in women with MI without angiographically demonstrable obstructive CAD. LGE is also common in this cohort of women, with an ischemic pattern of injury most evident. Vasospasm and embolism are possible mechanisms of ischemic LGE without plaque disruption. IVUS and CMR provide complementary mechanistic insights in female MI patients without obstructive CAD and may be useful in identifying potential etiologies and therapies.

Access site complications, especially HRT, remain a very important predictor of adverse procedural success and patient outcome.

Background A substantial minority of patients with acute coronary syndromes (ACS) do not have a diameter stenosis of any major epicardial coronary artery on angiography (“no obstruction at angiography”) of ≥ 50%. We examined the frequency of this finding and its relationship to race and sex. Hypothesis Among patients with myocardial infarction, younger age, female sex and non‐white race are associated with the absence of obstructive coronary artery disease at angiography. Methods We reviewed the results of all angiograms performed from May 19, 2006 to September 29, 2006 at 1 private (n = 793) and 1 public (n = 578) urban academic medical center. Charts were reviewed for indication and results of angiography, and for demographics. Results The cohort included 518 patients with ACS. There was no obstruction at angiography in 106 patients (21%), including 48 (18%) of 258 patients with myocardial infarction. Women were more likely to have no obstruction at angiography than men, both in the overall cohort (55/170 women [32%] vs 51/348 men [15%], P < 0.001) and in the subset with MI (29/90 women [32%] vs 19/168 men [11%], P < 0.001). Black patients were more likely to have no obstruction at angiography relative to any other subgroup (24/66 [36%] vs 41/229 [18%] Whites, 31/150 [21%] Hispanics, and 5/58 [9%] Asians, P = 0.001). Among women, Black patients more frequently had no obstruction at angiography compared with other ethnic groups (16/27 [59%] vs 17/59 [29%] Whites, 17/60 [28%] Hispanics, and 3/19 [6%] Asians, P = 0.001). Conclusions A high proportion of a multiethnic sample of patients with ACS were found to have no stenosis ≥ 50% in diameter at coronary angiography. This was particularly common among women and Black patients. Copyright © 2010 Wiley Periodicals, Inc. This work was supported by the Doris Duke Charitable Foundation. Dr Reynolds is a recipient of the Doris Duke Charitable Foundation Clinical Scientist Development Award. The authors have no other funding, financial relationships, or conflicts of interest to disclose.