Sex and race are associated with the absence of epicardial coronary artery obstructive disease at angiography in patients with acute coronary syndromes.

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 > or = 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 > or = 50% in diameter at coronary angiography. This was particularly common among women and Black patients.