Antihypertensive drug therapy associated with longer life expectancy

Dec 21 2011

More than 68 percent of Americans 65 and older - 80 percent age 75 and over - have hypertension (high blood pressure), according to a 2010 report by the Centers for Disease Control. Left untreated, this chronic condition can lead to stroke, heart attack, heart failure or premature death. Researchers at UMDNJ-Robert Wood Johnson Medical School have shown in a follow-up to the landmark clinical trial, Systolic Hypertension in the Elderly Program (SHEP), that the use of antihypertensive drug therapy is associated with longer life expectancy (survival). The follow-up study, "Association Between Treatment of Systolic Hypertension and Long-Term Survival" was published online today in the Journal of the American Medical Association.

"Nearly 22 years after the initiation of the SHEP trial, we can confirm the legacy effect of treating hypertension, particularly in the elderly. We report that the average patient would live one day longer for each month of treatment. This may correspond to more than a year for people who start treatment in their fifties," said John B. Kostis, MD, the John G. Detwiler Chair of Cardiology, chair of the department of medicine, and founding director of The Cardiovascular Institute of New Jersey, who led the study. "Physicians may wish to use these data to encourage their patients to be compliant with prescribed treatment, as control of hypertension increases life expectancy; reduces the risk of stroke, heart failure and heart attack; and improves their overall quality of life and allows patients to work for a longer period of time."

SHEP, which lasted from 1985 to 1990, assessed the effect of antihypertensive drug treatment in reducing the risk of stroke. It enrolled more than 4,700 participants with an average age of 72, all of whom had isolated systolic hypertension. Each participant was randomized to either the treatment group, which received chlorthalidone-based therapy, or to the placebo group. At its conclusion, the trial showed that chlorthalidone-based therapy for hypertension resulted in the prevention of about one out of two admissions for heart failure, one out of three fatal or non-fatal strokes and one out of four coronary heart disease events, but there were no significant differences in mortality. At the end of the trial, all participants in both groups were advised to receive treatment for hypertension.

In the current study, the research team obtained mortality and cause-of-death data for 100 percent of the participants through December of 2006. Using traditional as well as novel statistical methods, the researchers determined that the length in time that patients survived without experiencing a cardiovascular-related death was significantly longer for the group that received chlorthalidone treatment - approximately one day for every month of antihypertensive treatment.

Because of the average age of the trial group and the significance of competing causes of death, such as cancer, in that group, the researchers also analyzed in life expectancy for all-cause mortality, which resulted in a gain of one-half day for each month of antihypertensive treatment in the treatment group over the placebo group.

In addition to the clinical benefits described above, treatment of hypertension resulting in longer survival may yield important benefits, such as allowing a person to work for a longer period of time, thereby increasing their income earning potential. Treatment of hypertension also may provide a cost savings due to a reduced need for invasive cardiovascular and emergency procedures.