Different effects of antihypertensive regimens based on fosinopril or hydrochlorothiazide with or without lipid lowering by pravastatin on progression of asymptomatic carotid atherosclerosis: Principal results of PHYLLIS - A randomized double-blind trial

Background and Purpose - The Plaque Hypertension Lipid-Lowering Italian Study (PHYLLIS) tested whether (1) the angiotensin-converting enzyme (ACE) inhibitor fosinopril (20 mg per day) was more effective on carotid atherosclerosis progression than the diuretic hydrochlorothiazide (25 mg per day), (2) pravastatin (40 mg per day) was more effective than placebo when added to either hydrochlorothiazide or fosinopril, and (3) there were additive effects of ACE inhibitor and lipid-lowering therapies. Methods - A total of 508 hypertensive, hypercholesterolemic patients with asymptomatic carotid atherosclerosis were randomized to: (A) hydrochlorothiazide; (B) fosinopril; (C) hydrochlorothiazide plus pravastatin; and (D) fosinopril plus pravastatin, and followed up blindly for 2.6 years. B-Mode carotid scans were performed yearly by certified sonographers in 13 hospitals and read centrally. Corrections for drift were calculated from readings repeated at study end. Primary outcome was change in mean maximum intima-media thickness of far and near walls of common carotids and bifurcations bilaterally (CBM_max). Results - CBM _max significantly progressed (0.010±0.004 mm per year; P=0.01) in group A (hydrochlorothiazide alone) but not in groups B, C, and D. CBM _max changes in groups B, C, and D were significantly different from changes in group A. Changes in group A were concentrated at the bifurcations. "Clinic" and "ambulatory" blood pressure reductions were not significantly different between groups, but total and low-density lipoprotein cholesterol decreased by ≈1 mmol/L in groups C and D. Conclusions - Progression of carotid atherosclerosis occurred with hydrochlorothiazide but not with fosinopril. Progression could also be avoided by associating pravastatin with hydrochlorothiazide.