Abstract 5020: The Association between Different Measures of Blood Pressure and Coronary Artery Calcium in Postmenopausal Women
Background: The aim of this study was to determine the magnitude and significance of the associations between coronary artery calcium (CAC) and different measures of blood pressure among postmenopausal women.
Methods: Subjects were a subset of women aged 50 to 59 at baseline in the Women’s Health Initiative (WHI) clinical trial of conjugated equine estrogen (CEE) who underwent a one-time computed tomography (CT) scan of the chest following the end of the trial to determine CAC. At the baseline WHI clinic visit, CEE trial participants provided data on a wide range of factors to include blood pressure measurements which were measured twice with the participant in the seated position using a conventional mercury sphygmomanometer and appropriately sized cuffs.
Results: The sample consisted of 1,064 women with a mean age of 55.1 (2.8) years at WHI randomization and 64.8 (2.9) years at CAC ascertainment. The prevalence of a CAC score > 0 was 47%, while the prevalence of a CAC score >= 10 and > 100 was 39 and 19%, respectively. There was a linear association between the log-odds of any CAC and SBP while there was a curvilinear and inverse association with DBP that was independent of CVD risk factors and blood pressure medication status. For any value of diastolic blood pressure, the probability of CAC increased with higher levels of SBP. Conversely, for any given value of SBP, the probability of any CAC decreased with higher levels of DBP. Those with a PP >= 55 mmHg had nearly a two-fold higher odds for having any CAC (Odds Ratio: 1.95, 95% CI: 1.24 – 3.06) while individuals with isolated systolic hypertension (SBP >= 140 and DBP < 90) had a 73% higher odds for CAC (95% CI: 1.03 – 2.90, p = 0.04) independent of other risk factors and blood pressure medication status. There was no significant associations between mean arterial pressure and CAC.
Conclusions: In postmenopausal women over the age of 50 years, both SBP and DBP are relevant for determining the risk for coronary artery calcium. Notably, higher levels of pulse pressure and systolic blood pressure were strong determinants of CAC, while diastolic blood pressure was inversely related. Consequently, isolated systolic hypertension may be relevant in women. These results may be of clinical relevance for the prevention of coronary artery disease.
This research has received full or partial funding support from the American Heart Association, AHA National Center.