Angiotensin converting enzyme inhibitor-associated angioedema: higher risk in blacks than whites

We compared the incidence of angioedema during exposure to angiotensin converting enzyme inhibitors (ACEIs) in blacks with that in whites in a retrospective cohort study of Medicaid recipients from Michigan, Ohio and Tennessee during 1986- 1992. Medicaid administrative files were used to identify filled prescriptions for ACEIs and calcium channel blockers (CCBs), and to identify first episodes of angioedema that occurred during exposure to an ACEI or CCB. There were 48,776 black and 106,482 white patients with 43,989 and 114,448 person-years of exposure to an ACEI, respectively. For comparison, there were 49,004 black and 110,129 white patients with 43,064 and 117,684 person-years of exposure to a CCB, respectively. The incidence of angioedema in blacks ranged from 3.3 to 4.6 per 1000 person-years of ACEI exposure--three to four times higher than that for whites in each state. Controlling for a slightly greater incidence of angioedema in blacks and other covariates, black users of ACEIs had a 3.1-fold greater incidence than white users. First exposure to ACEIs was associated with a higher risk of angioedema than chronic exposure in blacks, but not whites. Among blacks, the rate of angioedema during the first 30 days of exposure was 11.4 times greater (95% confidence interval CI, 3.5 to 37.0) among ACEI users than CCB users; for those with at least 1 year of exposure, the rate was 4.5 times higher (95% CI, 2.6 to 8.0). Among whites, the increased risk of angioedema was more modest (rate ratio 1.7, 95% CI, 1.3 to 2.4 compared to CCB users) and did not differ by duration of ACEI use. In an analysis of angioedema cases and randomly selected controls in a subset of the full cohort, the greater risk of ACEI-associated angioedema in blacks was not explained by concurrent exposure to diuretics or antibiotics. Blacks may be at greater risk of angioedema when taking ACEIs than whites. Further study is necessary to confirm these findings, to examine effects of underlying disease on angioedema incidence, and to describe any racial differences in the severity of angioedema occurring with ACEIs.