The use of lipid-lowering medication is clearly associated in multiple research studies with reduced coronary heart disease (CHD) morbidity and mortality in patients with known CHD. Because results sometimes vary between controlled trials and real clinical practice, and because identification of particular patient subgroups that benefit would help in resource allocation, a cohort study in a clinical setting is useful. Rubins and associates reviewed CHD patient data files at five Veterans Affairs medical facilities, examining time to death from all causes as the primary outcome.
Lipid treatment of at least 30 days’ duration was noted for 43 percent of the 16,470 participants at some time during the 5.9-year follow-up. Statins were the most common therapy, with the majority of patients taking statins also receiving another lipid-lowering medication at some time during the study. Patients with and without diabetes were equally likely to be prescribed a statin. Fewer lipid-lowering medications were prescribed for older patients.
On average, the treated cohort of patients survived 15 months longer than the untreated group. There was a significant trend toward greater benefit among patients with the highest baseline cholesterol values. The relative risk reduction in total mortality over six years with the use of lipid-lowering medications was 25 percent, similar to that achieved in randomized trials. No clear benefit was noted in the treatment of persons with diabetes.
The authors conclude that lipid-lowering therapy imparts substantial all-cause mortality benefit in persons with CHD in a clinical setting such as that occurring in randomized trials. The problem of undertreatment in older patients is disturbing, because the obtainable absolute risk reduction achieved with treatment of this group is higher than that of a younger group. The relative benefit of lipid-lowering medications in persons with CHD who have relatively normal levels of cholesterol remains less certain. The absence of increased benefit in treated persons with diabetes may result from the use of all-cause mortality as an end point rather than using major coronary events as the examined outcome.