Hispanic Women Reap Greater Benefit From Blood Pressure Control

GAINESVILLE, Fla., July 13 -- Hispanic women with coronary artery disease and hypertension achieved better blood pressure control than non-Hispanic white counterparts who were treated with the same antihypertensive drugs.
The finding emerged from a post hoc analysis of data from the INVEST trial that compared a calcium channel-blocker-based regimen to a beta-blocker-based regimen, Rhonda M. Cooper-DeHoff, Pharm., D., of the University of Florida, and colleagues, reported in the June issue of the Journal of Women's Health.
They found that 75% of Hispanic women achieved blood pressure control versus 68% of non-Hispanic white women (P<0.001).
Non-Hispanic women were also significantly less likely to have a first heart attack, a nonfatal stroke, or die from any cause during 24 months follow-up (HR 0.84, 95% CI, 0.71-0.98 P=0.03).
"To our knowledge, this randomized treatment trial is the first to observe a significant difference in serious outcomes among women of different ethnic makeup," they wrote.
INVEST (International VErapamil SR/Trandolapril STudy) randomized 22,576 participants to verapamil sustained release plus the ACE-inhibitor trandolapril (Mavik) as needed or atenolol plus hydrochlorothiazide. There was no difference in the primary endpoint of cardiovascular events or blood pressure control.
In the current analysis, the researchers compared outcomes of 5,017 Hispanic women with 4,710 non-Hispanic white women.
At baseline the Hispanic women were on average about three years younger than the non-Hispanic whites, and were more likely to have diabetes, angina, and peripheral artery disease (P<0.001 for all). But they were less likely to have hypercholesterolemia, and fewer were smokers (P<0.001 for both) than non-Hispanic whites.
The Hispanic women also had lower baseline mean systolic but higher baseline mean diastolic pressure (P<0.001) for both).
Although all women were using antihypertensive medications at baseline, only 24% of the Hispanic women and 20% of the non-Hispanic whites had blood pressure well controlled at baseline.
Among the findings:
Mean diastolic blood pressure reduction was greater in Hispanic women than non-Hispanic whites (P<0.001).
Blood pressure reduction was comparable with either verapamil or atenolol-based treatments for all women.
Seventy-nine percent of Hispanic women and 84% of non-Hispanic white women required two or more drugs to achieve blood pressure control.
History of heart failure, prior stroke/transient ischemic attack, diabetes, older age, and prior MI were all predictive of increased risk of primary outcome (first MI, nonfatal stroke, all cause mortality) in Hispanic women.
Ethnicity was determined by patients self report, which may not "reflect ancestral genetics," the investigators said.
Also Hispanic women generally had fewer baseline cardiovascular risk factors, "so our findings of lower risk for these events may not be surprising," they wrote.
But even after adjusting for those baseline differences, the risk of primary and secondary events remained lower, "suggesting that other factors are contributing to this reduced risk," the authors wrote.
Finally the authors concluded that because there was no difference in outcomes between the two regimens, clinicians could be confident that either regimen is effective in this population.
The study was supported by Abbott Laboratories and the University of Florida. Dr. Cooper-DeHoff disclosed no financial conflicts. Primary source: Journal of Women's HealthSource reference: Cooper-DeHoff, RM "Influence of Hispanic Ethnicity on Blood Pressure Control and Cardiovascular Outcomes in Women with CAD and Hypertension: Findings from INVEST" J Women Health, 2007 16:632-640