THERAPY AND PREVENTION HYPERLIPILDEMIA Low-fat diet and regular, supervised physical exercise in patients with symptomatic coronary artery disease: reduction of stress-induced myocardial ischemia

The effects of physical exercise and normalization of serum lipoproteins on stressinduced myocardial ischemia were studied in 18 patients with coronary artery disease, stable angina pectoris, and mild hypercholesterolemia (total serum cholesterol 242 + 32 mg/dl). These patients underwent a combined regimen of low-fat/low-cholesterol diet and regular, supervised physical exercise at high intensity for 12 months. At 1 year serum lipoproteins has been lowered to ideal levels (serum cholesterol 202 ± 31 mg/dl, low-density lipoproteins 130 + 30 mg/dl, very low-density lipoproteins 22 ± 15 mg/dl, serum triglycerides 105 [69 to 304] mg/dl) and physical work capacity was improved by 21% (p < .01). No significant effect was noted on high-density lipoproteins, probably as a result of the low-fat/high-carbohydrate diet. Stress-induced myocardial ischemia, as assessed by thallium-201 scintigraphy, was decreased by 54% (p < .05) despite higher myocardial oxygen consumption. Eighteen patients matched for age and severity of coronary artery disease served as a control group and "usual medical care" was rendered by their private physicians. No significant changes with respect to serum lipoproteins, physical work capacity, maximal rate-pressure product, or stress-induced myocardial ischemia were observed in this group. These data indicate that regular physical exercise at high intensity, lowered body weight, and normalization of serum lipoproteins may alleviate compromised myocardial perfusion during stress. Circulation 77, No. 1, 172-181, 1988. REDUCTION OF DIETARY FAT consumption, weight reduction in overweight patients, and regular physical exercise are the mainstays of nearly all rehabilitation programs advocated for patients recovering from myocardial infarction or suffering from symptomatic coronary artery disease. Improved tolerance of physical stress and elevation of the anginal threshold are observed quite regularly and support the validity of this concept. The mechanisms underlying these salutatory effects are thought to be largely based on peripheral adaptations such as enhancement of capillary density in the muscle fibers recruited during training, 1 and From the Medizinische Universitatsklinik Heidelberg, Abteilung Innere Medizin III, Institut fur Dokumentation und Statistik, Heidelberg, West Germany. Supported by a grant from Bundesministerium fur Forschung und Technologie, Bonn. Address for correspondence: Gerhard Schuler, M.D., Medizinische Universititsklinik, Bergheimerstr. 56, 6900 Heidelberg. West Germany. Received Feb. 17, 1987; revision accepted Aug. 20, 1987. 172 an increase in maximal arteriovenous oxygen difference. 2,3 It remains a question of dispute whether this form of therapy also affects the course of the atherogenic process itself and ultimately improves compromised myocardial perfusion. Studies in experimental animals indicate that progression of coronary atherosclerosis may be halted or even reversed by normalization of serum lipoproteins.4 Moreover, intervention studies in patients with hyperlipidemia were successful in lowering the incidence of myocardial infarction and retarding progression of coronary atherosclerosis, suggesting that this concept may also be applicable to man.5'6 The present study was undertaken to test the hypothesis that a combination of lipid-lowering measures and regular physical exercise may not only increase exercise tolerance by means of peripheral adaptations, but actually improve myocardial perfusion in patients with symptomatic coronary artery disease. The rationale for CIRCULATION by gest on A ril 7, 2017 http://ciajournals.org/ D ow nladed from THERAPY AND PREVENTION-HYPERLIPIDEMIA the use of these measures simultaneously was that progression of coronary arteriosclerosis might be retarded by marked lowering of atherogenic serum lipoproteins, while antiatherogenic high-density lipoproteins (HDLs) and collateralization would be stimulated by frequent physical stress just below the anginal threshold.7->l Evaluation of the results was based on the assumption that improvement of myocardial perfusion should result in reduction of stress-induced ischemia despite constant or even increased myocardial