Although the role of antihypertensive therapy, particularly with diuretics and beta blockers, has been well studied in adult patients, this treatment may be less effective, or even harmful, in patients over 80 years of age. A group of international researchers conducted a meta-analysis to determine if antihypertensive treatment is beneficial in patients over 80 years of age.

The authors used personal contacts, literature review and the Cochrane Collaboration to identify randomized, controlled trials of anti-hypertensive therapy. Data on patients over 80 years of age were requested directly from the investigators. The five eligible trials included 1,670 patients who were 80 years of age or older and who were followed for an average of 3.5 years. Participants in the study group were predominately women (76 percent), with a mean age of 83 years, a range of 80 to 99 years and a mean blood pressure of 180/84 mm Hg. Only 7 percent of the patients smoked and 14 percent had diabetes. Previous myocardial infarction was reported by 5 percent of patients, and previous stroke was reported by 4 percent.

Investigators compared the occurrence of stroke, cardiovascular death, major cardiovascular events and congestive heart failure in both treated and nontreated elderly hypertensive patients. The rate of 57 strokes and 34 deaths from stroke in the 874 treated patients was significantly lower than the rate of 77 strokes and 28 deaths from stroke in the 796 control subjects. The authors calculate that antihypertensive therapy prevented about one third of strokes and that 100 patients would need to be treated each year to prevent one nonfatal stroke. In the treated patients, the rate of major cardiovascular events was reduced by 22 percent and the rate of heart failure was reduced by 39 percent. In contrast, in the double-blind trials, the rate of cardiovascular deaths increased by 11 percent and the rate of total mortality increased by 14 percent.

The authors discussed the difficulties of conducting studies on this topic and the problems associated with pooling data from several studies in meta-analysis. They conclude that the results concerning cardiovascular deaths and total mortality are inconclusive, but that treatment showed clear benefit in the avoidance of stroke, major cardiovascular events and heart failure in patients older than 80 years of age.