Association Between Chlorthalidone Treatment of Systolic Hypertension and Long-Term Survival

In the late 1980s, a randomized control trial of men and women over 60 years old with high blood pressure received either an anti-hypertensive drug (chlorthalidone) or a matching placebo in the Systolic Hypertension in the Elderly Program (SHEP) trial. Those who received the drug for the 4.5 years had blood pressure lower than the group that received the placebo (143/66 mm Hg versus 155/72 mm Hg). The treatment group also had significantly lower rates of non-fatal stroke, myocardial infarction and heart failure. After the trial, all participants were advised to receive active therapy for their hypertension.

These researchers conducted a long-term follow-up for mortality some 22 years later, matching personal identifiers of the participants to the National Death Index for deaths through the end of 2006. At the follow-up, those in the treatment group had a higher survival rate. They gained one day of life expectancy (free from cardiac death) for each month of treatment that they received. They had fewer deaths from cardiovascular causes (28% versus 31%) but similar rates of all-cause mortality (60%).

Such a strong message about the life-lengthening benefits of anti-hypertensive therapy may result in increased patient adherence to drug therapy.