Short-term effect of atorvastatin on ischaemic threshold in hypercholesterolaemic patients with stable ischaemic heart disease

Abstract

Objective — Hypercholesterolaemia is associated with a loss of endothelium-dependent vasodilation, which may facilitate the occurrence of myocardial ischaemia in patients with coronary artery disease (CAD). The improvement of endothelial dilator function after 4 to 6 weeks of oral lipidlowering therapy has been documented. Whether this early restoration of endothelial function by statins translates into anti-ischaemic effects is unknown.This study was designed to determine the effect of 4 weeks’ treatment with 80 mg atorvastatin daily on exercise-induced ischaemia in patients with stable ischaemic heart disease (IHD) receiving standard anti-anginal drug therapy.

Methods and results — A total of 41 patients with documented CAD, exercise-induced ischaemia and LDL-cholesterol > 130 mg/dl underwent exercise ECG, angina score and lipid level assessment at baseline, after 4 weeks of placebo treatment, and after 4 weeks of therapy with atorvastatin 80 mg. Primary endpoint was the change in time to 1 mm ST-segment depression (= ischaemic threshold) between placebo and treatment period.

Atorvastatin treatment resulted in a 55% reduction of low-density lipoprotein (LDL) cholesterol (from mean of 162 (SD 32) to 72 (20) mg/dl). For a comparable rate-pressure product, the average time to 1 mm ST-segment depression was 295 (112) s at baseline, 314 (149) s after placebo and 301 (131) s after atorvastatin, indicating that the ischaemic threshold was not significantly modulated after 4 weeks of atorvastatin treatment.There was also no significant change in global angina score or in time to maximal ST-segment depression.

Conclusions — High-dose atorvastatin treatment for 4 weeks drastically reduced LDLcholesterol. However, the present study did not demonstrate a significant effect on the ischaemic threshold in patients with stable IHD already under treatment with anti-ischaemic agents.

Key Words:

• myocardial ischaemia
• hypercholesterolaemia
• statin