NONPHARMACOLOGIC THERAPY FOR CORONARY-ARTERY ATHEROSCLEROSIS - RESULTS OF PRIMARY AND SECONDARY PREVENTION TRIALS

The association between abnormal serum lipoprotein levels and coronary atherosclerosis has been established by extensive clinical, experimental, and epidemiologic evidence. Recent angiographic trials in patients with coronary artery disease have demonstrated that improvement in serum lipids and other risk factors has a favorable effect on coronary lesions and reduces coronary events and interventions. Most trials of coronary disease prevention have used intensive pharmacologic therapy, but several have involved only nonpharmacologic intervention. The latter investigations include both primary and secondary prevention studies. Three controlled, nonpharmacologic primary prevention trials with long-term follow-up used dietary management aimed at lowering serum cholesterol levels; one trial also included smoking cessation, and one used a comprehensive approach to risk-factor modification. Serum cholesterol levels and other risk factors were significantly decreased in the intervention groups but were unaltered in the control populations. After periods of 5 to 10 years, reductions of 20% to 45% in coronary events were observed in the intervention groups compared with controls. Four secondary intervention trials examined the effect of nonpharmacologic therapy alone on coronary artery disease regression; three of these trials included control groups. All of the trials focused on reduction of elevated serum cholesterol levels with a low-fat diet, and several included interventions for other risk factors. Serum cholesterol levels fell by 14% to 24% in treated patients compared with 4% to 9% in controls. Although these trials were of relatively short duration (1 to 3 years) and included small numbers of patients (36 to 90), each demonstrated favorable effects on coronary lesions and three revealed clinical benefits. It is concluded that nonpharmacologic therapy can significantly improve atherosclerosis risk factors, favorably alter coronary lesions, and potentially reduce coronary events or interventions, which provides a rationale for more aggressive risk-factor management than is currently practiced by many physicians.