Cost analysis of amlodipine versus enalapril in patients with coronary artery disease and normal blood pressure

Abstract

To analyse 2-year hospitalization and cost data collected during a prospective, double-blind, randomized, controlled trial comparing amlodipine, enalapril and placebo in normotensive patients with coronary artery disease (CAD). All patients who were enrolled in the CAMELOT study were included in this economic substudy. Patients with CAD and normal blood pressure were randomized to amlodipine, enalapril or placebo, and followed up for 24 months (between 1999 and 2004). Data on hospitalizations and medication use were obtained from the clinical trial. Costs were assigned from secondary sources. Total costs ($US, year 2004 values) were estimated as the sum of costs associated with cardiovascular hospitalizations, study medications and concomitant cardiovascular medications. Costs and resource use were analysed by treatment arm overall and for selected patient subgroups. Cost differences were evaluated using nonparametric bootstrap techniques. Of 1991 patients enrolled, 663 were treated with amlodipine, 673 were treated with enalapril and 655 were treated with placebo. Significantly fewer patients were hospitalized for cardiovascular reasons in the amlodipine group (16.4%) than in the placebo group (22.7%; p < 0.01), but not compared with the enalapril group (20.1%; p = 0.09). The amlodipine group also had numerically fewer days in hospital per patient (1.1) than the enalapril (1.3) and placebo (1.5) groups. Mean 2-year per-patient costs in the amlodipine group were estimated to be $US 609 and $US 717 lower than for the placebo and enalapril groups, respectively. These results suggest that use of amlodipine may reduce costs of care among CAD patients with normal blood pressure.