Effects of normal, pre-hypertensive, and hypertensive blood pressure levels on progression of coronary atherosclerosis

Abstract

Objectives: The purpose of this study was to evaluate the effects of normal blood pressure (BP), pre-hypertension, and hypertension on progression of coronary atherosclerosis.

Background: The Seventh Report of the Joint National Committee on the Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC-7) classifies BP as normal, pre-hypertension, and hypertension. The effects of these categories on progression of coronary atherosclerosis are unknown.

Methods: The 274 patients who completed the intravascular ultrasound (IVUS) substudy of the CAMELOT (Comparison of Amlodipine Versus Enalapril to Limit Occurrences of Thrombosis) trial were included. The entry criteria were > or =1 angiographic coronary stenosis >20% and diastolic BP <100 mm Hg. Patients underwent a baseline coronary IVUS, which was repeated after 2 years of amlodipine, enalapril, or placebo therapy. The BP was evaluated periodically, and the averages of the measurements were used in the analyses.

Results: Mean BP throughout the study was 127.0 +/- 12.0/75.5 +/- 6.8 mm Hg. In multivariable analysis, significant determinants of progression included systolic BP (r = 0.16; p = 0.006) and pulse pressure (r = 0.14; p = 0.02). Patients with "hypertensive" average BP had a 12.0 +/- 3.6 mm3 (least-square mean +/- SE) increase in atheroma volume, those with "pre-hypertensive" BP had no major change (0.9 +/- 1.8 mm3), and those with "normal" BP had a decrease of 4.6 +/- 2.6 mm(3) (p < 0.001 by analysis of covariance; p < 0.05 for comparison of all pairs).

Conclusions: The most favorable rate of progression of coronary atherosclerosis is observed in patients whose BP falls within the "normal" JNC-7 category (i.e., systolic BP <120 mm Hg and diastolic BP <80 mm Hg). This study suggests that in patients with coronary artery disease, the optimal BP goal may be substantially lower than the <140/90 mm Hg level.