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

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 UNC-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 >= 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 mm 3 (least-square mean +/- SE) increase in atheroma volume, those with pre-hypertensive BP had no major change (0.9 +/- 1.8 mm(3)), 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 maybe substantially lower than the < 140/90 mmHg level.