Effect of long-term cholesterol-lowering treatment with HMG-CoA reductase inhibitor (simvastatin) on myocardial perfusion evaluated by thallium-201 single photon emission computed tomography

Fifteen patients with either angina pectoris or old myocardial infarction, who had positive Tl-201 single photon emission computed tomography (SPECT) imaging and coronary sclerosis of more than 50%, were treated with an HMG-C oA reductase inhibitor (simvastatin) for more than 1 year. They were compar ed with an untreated control group (n=25). Total cholesterol decreased 22% and high-density lipoprotein (HDL) increased 9% with simvastatin; both chan ges were significantly different from those in controls. Long-term simvasta tin induced improvement of myocardial perfusion on Tl-201 SPECT images both during exercise and at rest, which was also significantly different from c ontrols. In addition, the improvement of myocardial perfusion on Tl-201 SPE CT images was clearly related to the improvements in cholesterol values, es pecially nonHDL cholesterol. Thus, the greater the decrease in nonHDL chole sterol, the greater the improvement in myocardial perfusion at rest or duri ng exercise with long-term treatment using an HMG-CoA reductase inhibitor. These findings indicate that the improvements in cholesterol values caused by HMG-CoA reductase inhibitor therapy are related to improvements of myoca rdial perfusion seen on Tl-201 SPECT images.