RESUMO
OBJECTIVES: To evaluate if cholesterol lowering therapy with simvastatin increases myocardial perfusion, assessed by Thallium-201 single photon emission computed tomography (SPECT) after dipyridamole, in patients with coronary artery disease. PATIENTS AND METHODS: Ten hypercholesterolemic subjects with coronary artery disease were selected for a pilot study. Lipid and lipoprotein analysis and Thallium-201 SPECT were performed before and after 16 weeks of treatment with 40 mg of simvastatin QD. SPECT images were qualitatively analyzed in 8 myocardial segments using a 4 point scoring system. Quantitative evaluation was performed in 13 segments. The myocardial region with the maximal mean counts per pixel on the stress study was considered the reference region. TI201 activity in all other myocardial regions was expressed as a percentage of the activity in the reference region. RESULTS: Total cholesterol and LDL cholesterol were reduced by 28.4% and 37.1% with treatment. Global myocardial perfusion was increased in all patients. Qualitative analysis demonstrated that cholesterol lowering improved myocardial perfusion during dipyridamole stress. Quantitative analysis showed an increased global perfusion during stress (41.8% vs 54.6%; p < 0.0001), due to increased perfusion of previous ischemic segments (32.4% vs 49.4%; p < 0.0001) but without changes in previous normally perfused segments (71.5% vs 71.3%). CONCLUSION: Reduction of cholesterol levels in hypercholesterolemic subjects with coronary artery disease increases myocardial perfusion in ischemic segments during dipyridamole stress test as assessed by single photon emission computed tomography (SPECT).