Approximately 80 percent of all deaths from coronary heart disease (CHD) occur in persons older than 65 years, and CHD is the leading cause of death in this age group. At least 25 percent of men and 42 percent of women in this age group have serum total cholesterol levels above 240 mg per dL. Nevertheless, the association between elevated cholesterol levels and CHD is not as strong in elderly persons as in younger adults, and the benefits of reducing cholesterol levels have not been clearly demonstrated in older patients. Dalal and Robbins reviewed the evidence of benefit from lipid- lowering therapy in elderly patients.
They reviewed data from four secondary prevention trials that included significant numbers of persons older than 65 years. The Scandinavian Simvastatin Survival Study followed more than 1,000 patients for six years and reported a 33 percent reduction in all- cause mortality, a 42 percent reduction in CHD mortality, and a 33 percent reduction in major coronary events in the treated group. The absolute risk reduction was 6.2 percent, and an estimated 10 CHD-related deaths and 17 major cardiac events were prevented per 1,000 patient-years of treatment. Similar results were reported from the Cholesterol and Recurrent Events trial, which followed 1,283 patients with established CHD who were treated with pravastatin for five years, and from the Long-term Intervention with Pravastatin in Ischemic Disease (LIPID) trial, which followed 3,514 patients for six years.
From these studies and the Veterans Affairs study of men with established CHD and continuing risk factors, the authors conclude that in patients older than 65, secondary prevention of CHD with lipid-lowering medications is effective and does not increase mortality or cause significant adverse events. They recommend statins as first-line therapy, with bile acid sequestrants as alternatives unless triglycerides are elevated (see the accompanying table on page 1998). The evidence of benefit from drug therapy is less clear in patients older than 75. In these patients, overall general health and comorbid conditions must be considered.
For primary prevention in older patients, the National Cholesterol Education Program recommends lifestyle changes as first-line therapy because of unknown effectiveness and concerns about side effects of lipid-lowering medications. Two large studies of primary prevention that included significant numbers of elderly patients concluded that primary prevention benefitted older patients. The West of Scotland Coronary Prevention Study of pravastatin included 3,370 men older than 55. After five years, treatment was associated with a 22 percent reduction in total mortality and a 31 percent reduction in coronary events. The rate of first major coronary events also was decreased (by 37 percent after 5.2 years of follow-up) in the Air Force/Texas Coronary Atherosclerosis Prevention Study that examined lovastatin therapy for primary prevention in 1,416 patients age 65 to 73. In these and smaller studies, medication has effectively provided primary prevention for CHD without causing significant adverse events.
The authors conclude that lipid-lowering therapy should be considered for patients age 65 to 75 years who have a history of CHD or a moderate to high risk for CHD. In patients older than 75, decisions should be made for each individual based on life expectancy, comorbidities, and other concerns.