Relationship of antihypertensive treatment to plasma markers of vascular inflammation and remodeling in the Comparison of Amlodipine versus Enalapril to Limit Occurrences of Thrombosis study

Background: Antihypertensive agents lower the risk of cardiovascular events, but whether they affect pathways important in inflammation and plaque remodeling in atherosclerosis is uncertain. We assessed whether 2 commonly used antihypertensive agents affected plasma biomarkers reflecting specific inflammatory and remodeling processes over 2 years in the Comparison of Amlodipine versus Enalapril to Limit Occurrences of Thrombosis (CAMELOT) study. Methods: The study was a randomized controlled trial of 2 antihypertensives (amlodipine and enalapril) compared with placebo in patients with coronary artery disease and diastolic blood pressure less than 100 mm Hg. In 196 subjects who had baseline and 2-year intravascular coronary ultrasound examinations, we measured plasma interleukin 18, interleukin 1 receptor antagonist, matrix metalloproteinase 9, neopterin, and C-reactive protein. Results for both treatment groups were pooled and compared with placebo. Results: Antihypertensive treatment with either agent significantly lowered diastolic blood pressure (-4.7 vs placebo 1.3 mm Hg, P =.002) and progression of coronary atheroma (Δ percent atheroma volume 0.6 vs placebo 2.1, P =.031). Antihypertensive therapy did not affect plasma biomarkers of inflammation or plaque remodeling in the 135 subjects with baseline and 2-year biomarker samples. Progression in percent atheroma volume was significantly less in subjects taking statins at baseline (-2.5%, P =.0008). Conclusions: In patients with coronary artery disease and well-controlled risk factors, antihypertensive therapy lowered blood pressure and progression of coronary atherosclerosis but did not affect plasma biomarkers of inflammation and remodeling. Antihypertensives may decrease atheroma progression by mechanisms other than those reflected by these plasma biomarkers.