Are there differences in risk factor profiles and frequency of CT/MRI-based infarcts among African American stroke patients with and without hypertension? A report from the African American Antiplatelet Stroke Prevention Study (AAASPS)

Abstract

BACKGROUND; African Americans (AAs) have a high risk of stroke and a high prevalence of cardiovascular risk factors. Little is known about stroke risk profiles among non-hypertensive AAs.

Methods: African American Antiplatelet Stroke Prevention Study (AAASPS) enrollees with a history of hypertension (htn) were compared to those without htn for history of traditional cardiovascular risk factors and number and distribution of CT/MRI infarcts. Estimated odds ratios are presented describing the association between selected risk factors and htn status. The estimated odds ratios and 95% confidence intervals (CI) were obtained using multivariate logistic regression.

Results: The database for this analysis included 1012 patients with htn and 74 patients without htn. When compared to those with htn, those without htn were more commonly men (59% vs. 46%; p = 0.030), current cigarette smokers (55% vs. 37%; p = 0.001), were younger (median age: 59 years vs. 62 years; p = 0.064), had higher education (11.7 +/- 2.9 vs. 11.1 +/- 3.1; p = 0.024), had a higher number of acute strokes of unknown cause (23% vs. 13%; p=0.060), and less commonly had a history of diabetes (25% vs. 41%; p = 0.007). Those without htn had a lower mean number of old infarcts on MRI (0.94 +/- 1.40 vs. 1.45 +/- 1.60; p = 0.045), and a higher number of mean recent infarcts on CT (1.30 +/- 1.15 vs. 0.93 +/- 1.01; p = 0.031). Multivariate analysis to predict those without htn showed that these patients were more likely to be current cigarette smokers (OR = 2.89; CI = 1.60,5.49) and have higher education (OR = 1.08, CI = 0.996,1.17), and were less likely to have old CT/MRI-based infarcts (OR = 0.46; CI = 0.26,0.76).

Conclusions: AAs without htn may have a different cardiovascular risk factor profile and CT/MRI profile than AAs with htn. This baseline profile among AAs without htn may predict lower stroke recurrence rates in this ongoing trial.