Effects of Normal, Pre-Hypertensive, and Hypertensive Blood Pressure Levels on Progression of Coronary Atherosclerosis

ObjectivesThe purpose of this study was to evaluate the effects of normal blood pressure (BP), pre-hypertension, and hypertension on progression of coronary atherosclerosis.BackgroundThe 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.MethodsThe 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 ≥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.ResultsMean 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 mm3(p < 0.001 by analysis of covariance; p < 0.05 for comparison of all pairs).ConclusionsThe 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.