Achievement of target plasma cholesterol levels in hypercholesterolaemic patients being treated in general practice

Abstract

A total of 1028 hypercholesterolaemic men and women aged 18-75 participated in an open label, randomised, parallel group, 6-month treatment-to-target study conducted in 240 general practices throughout Australia. The study compared atorvastatin monotherapy with simvastatin monotherapy or, if necessary, with the combination of simvastatin and cholestyramine in terms of their abilities to achieve a plasma total cholesterol target of<5.0 mmol/l. The initial daily dose of each drug was 10 mg. If the target was not achieved, the dose was doubled at 6 week intervals to a maximum daily dose of 80 mg atorvastatin or 40 mg simvastatin, with the simvastatin supplemented if necessary with 4 g cholestyramine. The percentage of patients achieving the target at 10 and 20 mg doses of atorvastatin were comparable to 20 and 40 mg of simvastatin, respectively. Despite relatively high baseline levels of plasma total cholesterol (mean levels of 7.41 and 7.31 mmol/l in the atorvastatin and simvastatin groups, respectively) the majority of patients in each group achieved the plasma total cholesterol target of<5.0 mmol/l. Treatment with atorvastatin achieved the target in 83% of patients, while simvastatin (or simvastatin plus cholestyramine) achieved the target in 66% of the patients (P<0.005). The target was achieved with 10 mg atorvastatin in 38% of patients and with 10 mg simvastatin in 26% of cases (P<0.005). In patients whose baseline cholesterol levels were between 5.6 and 6.5 mmol/l, 95% of the atorvastatin group and 86% of the simvastatin group reached the target. Even with baseline cholesterol levels between 7.6 and 8.5 mmol/l, the target was reached in 78% of the atorvastatin group and 61% of the simvastatin group. It is thus realistic for general practitioners to expect the majority of their at risk patients to achieve target plasma cholesterol levels that have been shown in population studies to be associated with relatively low rates of coronary heart disease. These targets are achieved in significantly more patients and at lower mg doses with atorvastatin than simvastatin.