Clinical and coronary arteriographic profile of 100 black Americans: focus on subgroup with undiagnosed suspicious chest discomfort.

To help answer questions regarding the percentage of black patients catheterized for suspected cardiac ischemia who are found to have negative coronary arteriograms, and how this percentage compares with that of similarly classified white patients, the coronary arteriographic and left ventriculographic findings of 100 consecutive blacks were reviewed and compared with those of 226 contemporaneously catheterized whites. After excluding patients with prior histories of a clinical cardiac ischemic event, invasive therapeutic intervention for coronary artery disease (CAD), and nonatherosclerotic cardiac disease, a subgroup of 50 black and 104 white patients remained with undiagnosed chest discomfort that was suspicious for cardiac ischemia. Of this subgroup, 68 percent of the black patients showed no or insignificant CAD by arteriography, as compared with 21 percent of the white patients (P < .001). An incidental but note-worthy finding pertaining to this same subgroup was that 18 percent of the black patients who underwent arteriography and were found to have no CAD exhibited a subnormal left ventricular ejection fraction; in contrast, none of the white patients in the same category did so (P < .05).