Treatment of hypertension markedly reduces the risk of hypertension-related intracerebral hemorrhage (ICH), according to findings of the Ethnic/Racial Variations of ICH (ERICH) study.
A large case-control study with recruitment focused on minority populations, ERICH was designed to evaluate the risk of treated and untreated hypertension on the development of ICH among whites, blacks, and Hispanics. Researchers found that untreated hypertension is associated with a 9-fold or greater risk of ICH, regardless of race, but is significantly more common among blacks and Hispanics than whites with ICH.
The findings were reported at the 2016 International Stroke Conference in Los Angeles, by K.B. Walsh and colleagues.
Researchers hypothesized that ICH risk related to treated or untreated hypertension would vary based on race/ethnicity. Previous research has demonstrated that hypertension is a significant risk factor for ICH in predominantly white populations.
Between September 2010 and June 2015, researchers enrolled 891 white, 833 black, and 599 Hispanic case/control pairs. Cases were drawn from 42 centers and were identified by hot-pursuit (active surveillance). Controls, recruited by random-digit dialing, were matched to cases (1:1) by age (+/-5 years), sex, race/ethnicity, and metropolitan area. Whether participants had a history of hypertension and/or took antihypertensive medication was determined by interview.
Results indicated that untreated hypertension was more prevalent in blacks and Hispanics with ICH than in whites with the 2 conditions (43.3% and 48.3% vs 33.2%; P=.0002 and P<.0001, respectively). Even after adjustment for health insurance status, risk remained significantly different for whites compared with Hispanics (P=.002), but not for whites compared with blacks (P=.197).
Treated hypertension was a significant risk factor for ICH in whites (odds ratio [OR]:1.72; 95% confidence interval [CI]: 1.33- 2.22; P<.0001), blacks (OR: 3.04; 95% CI: 2.13-4.34; P<.0001), and Hispanics (OR: 2.57, 95% CI: 1.64-4.00; P<.0001) in multivariate analyses adjusted for alcohol use, anticoagulation, hypercholesterolemia, education, and insurance status. However, for all 3 groups, untreated hypertension posed a much greater risk (whites OR: 9.53; 95% CI: 5.88-15.45; P<.0001; blacksOR: 11.10; 95% CI: 7.06- 17.47; P<.0001; Hispanics OR: 9.65; 95% CI: 5.49-16.95; P<.0001). Depending on the ICH subtype, ORs ranged from 3.50 to 24.81 and statistical significance was achieved for all subtypes and race/ethnic groups.
As the authors noted, while treating hypertension does not eliminate the risk of ICH, it does reduce it markedly. They concluded that treatment of hypertension is likely to have a sizeable impact on ICH risk.
More ISC 2016 coverage here.
Walsh KB, Adeoye O, Sekar P, et al. Abstract 126. Importance of untreated hypertension for intracerebral hemorrhage. Presented at the International Stroke Conference; February 17-19, 2016; Los Angeles, CA.