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 201Tl single photon emission computed tomography (SPECT) imaging and coronary sclerosis of more than 50%, were treated with an HMG-CoA reductase inhibitor (simvastatin) for more than 1 year. They were compared with an untreated control group (n = 25). Total cholesterol decreased 22% and high-density lipoprotein (HDL) increased 9% with simvastatin; both changes were significantly different from those in controls. Long-term simvastatin induced improvement of myocardial perfusion on 201Tl SPECT images both during exercise and at rest, which was also significantly different from controls. In addition, the improvement of myocardial perfusion on 201Tl SPECT images was clearly related to the improvements in cholesterol values, especially nonHDL cholesterol. Thus, the greater the decrease in nonHDL cholesterol, the greater the improvement in myocardial perfusion at rest or during 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 myocardial perfusion seen on 201Tl SPECT images.

Effect of long-term exercise training on regional myocardial perfusion changes in patients with coronary artery disease.

The cardiac rehabilitation of patients with coronary artery disease (CAD) promotes exercise tolerance, improves left ventricular function, and decreases the heart rate and systolic blood pressure at the same load intensity. Several studies have shown that cardiac rehabilitation improves myocardial perfusion in CAD patients. However, the long-term (> or = 1 year) effect of cardiac rehabilitation on myocardial perfusion is still controversial. The effect of long-term exercise training on myocardial perfusion in CAD patients was assessed using thallium-201 (201Tl) exercise studies at a baseline (4 months after the onset of CAD) and at a 1-year or more follow-up in 58 patients with stable CAD. The subjects had been divided into a training group (n=35) participating in supervised exercise 2 times per week for the follow-up period, and the control group (n=23). There was an improvement in the myocardial perfusion on stress 201Tl scintigraphy in 20 of the 35 (57.1%) trained patients and in 3 of the 23 (13.0%) of the control patients (p<0.001). The number of 201Tl stress myocardial perfusion defect segments was significantly decreased after the cardiac rehabilitation training (231 to 153 segments), but showed no change in the control group (158 to 156 segments) (p<0.01). In spite of no significant differences in the number of involved coronary arteries, it improved (12/17 patients: 70.6%) more in the patients who had trained for more than 2 years compared to the patients who had trained for less than 2 years. The exercise tolerance increased in 25 of the 35 training group patients (71.4%), and in only 3 of the 23 control group patients (13.0%). The peak double products increased from 20,131+/-6,010 to 28,370+/-5,600 (p<0.01) in the training group, and showed no change in the control group (20,567+/-5,112 to 20,964+/-7,728 (NS)). The results indicated that the long-term physical training increased exercise tolerance and the double products of CAD patients. In addition, the training resulted in improved cardiac perfusion as evidenced by 201Tl scintigraphy. The findings suggest that exercise training is an advisable and effective treatment for patients with CAD.