Despite a statistically significant decline in ischemic events, the overall mortality in these studies was the same or slightly higher than that with placebo. The causes of death were mainly noncardiovascular and primarily due to motor vehicle accidents and other violent deaths. Criticisms of the studies are that it would require longer time and a larger sample size to show a reduction in total mortality. However, the overall mortality may not be a suitable goal to evaluate the effect of cholesterol treatment. Because the nonfatal infarction rate had been reduced, the sequelae of CAD, such as ischemic cardiomyopathy, were simultaneously prevented, and therefore the quality of life was improved.
How promising is cholesterol reduction in people with known CAD?
Secondary prevention is very promising. In the Coronary Drug Project, nicotinic acid effectively reduced LDL and very low density lipoprotein (VLDL) levels and increased HDL-C in male heart attack victims, resulting in a 29% lower rate of myocardial infarction recurrence than with placebo. The overall mortality in the treated group was not initially significant but later showed an 11% reduction at the end of 9 years. In the Stockholm Ischemic Heart Study, a combination of clofibrate and nicotinic acid showed a 36% reduction of CAD-related mortality in most myocardial infarction victims compared to the control group.
How important is diet in cholesterol management?
In the Japan-Honolulu-San Francisco Study, Japanese persons who moved to Hawaii or California, where they were exposed to a cholesterol-rich diet, had a higher incidence of CAD accompanied by a rise in serum cholesterol levels compared to a matched Japanese population remaining in Japan. These findings emphasize the influence of dietary cholesterol in the same genetic background.
Is hypertriglyceridemia an independent CAD risk factor?
Despite many recent epidemiologic and clinical studies suggesting a positive correlation between an elevated triglyceride level and CAD, the role of triglycerides as an independent risk factor remains controversial.
In persons with CAD, an elevated triglyceride level was usually associated with a low HDL or a high LDL-C, well-established major CAD risk factors.
Multivariate analysis failed to document the independent relation between hypertriglyceridemia and the CAD.
Hypertriglyceridemia is frequently found in various disease states (ie., diabetes mellitus, chronic renal failure, obesity) that are already prone to CAD development.