Secondary prevention of heart disease amongst patients with lipid abnormalities: Practice and trends in the United States

Patients with established coronary disease and abnormalities of lipid metabolism represent a particularly important subgroup, since their mortality risk is typically 10 times greater than that amongst subjects with comparable risk factors but no clinical history. Such patients are commonly treated initially with anti-anginal therapy; if ischaemic symptoms persist they often undergo revascularization (bypass or angioplasty). While invasive procedures restore blood now and relieve ischemia, they do not, in most cases, reduce risk of subsequent MI or death, or alter the underlying atherogenic process(es). Despite this, there has been a progressive 54% decline in age adjusted cardiac mortality over the period 1960-1995, which appears best attributable to US lifestyle changes. In particular, the past decade has provided compelling evidence for the merits of a fourth approach: comprehensive risk factor management. Clinical outcome studies have confirmed the substantial merit of aspirin prophylaxis and of intensive lipid-lowering therapy in secondary prevention. Prospective angiographic trials and evidence from studies of vascular biology have provided insight into mechanisms of benefit. As a consequence, lipid therapy and aspirin use have increased greatly among middle aged and older US citizens, especially those with CAD. The growth of comprehensive medical management now rivals that of invasive revascularization in secondary prevention.