Antihypertensive therapy increases life expectancy
MedWire News: Chlorthalidone treatment significantly reduces mortality and increases life expectancy, data from the SHEP trial show.
Each month of antihypertensive therapy was associated with a 1-day prolongation of life expectancy free from cardiovascular (CV) death, report John Kostis (UMDNJ-Robert Wood Johnson Medical School, Brunswick, New Jersey, USA) and colleagues in JAMA.
They used data from SHEP (Systolic Hypertension in the Elderly Program), which involved patients aged 60 years or over with isolated systolic hypertension who were recruited between March 1, 1985 and January 15, 1988.
At the end of a 4.5-year randomized phase of the study, where patients were randomly allocated to receive treatment with chlorathalidone 12.5 mg daily (n=2365) or placebo (n=2371), all participants were advised to receive chlorathalidone therapy. The time interval between the start of recruitment and ascertainment of death was 21 years and 10 months.
The current study found that at the 22-year follow-up, life expectancy gain, expressed as the area between the active (n=2365) and placebo (n=2371) survival curves was 105 days for all-cause mortality and 158 days for CV death.
Therefore, each month of active treatment was associated with an approximate 1-day extension in life expectancy, say the authors.
Patients receiving chlorthalidone had a significantly higher survival rate free from CV death than those on placebo (p=0.03), but a similar survival rate for all-cause mortality.
A total of 1416 (59.9%) chlorthalidone and 1435 (60.5%) placebo patients died during follow-up.
CV death was significantly lower in chlorthalidone patients than placebo patients, at 28.3% versus 31.0% (p=0.02). However, the between-group difference for all-cause mortality was nonsignificant.
For all-cause mortality, the time to the 70th percentile of survival was 0.56 years longer in the chlorthalidone group than in the placebo group, at 11.53 versus 10.98 years (p=0.03), and was 1.41 years longer for survival free from CV death, at 17.81 versus 16.39 years (p=0.01).
"This gain in life expectancy is important, because it occurred among persons with a mean age of 72 years at baseline," write the authors.
They conclude: "Reporting that each month of antihypertensive therapy was associated with 1 day of prolongation of life expectancy free from CV death is a strong message that may result in increased patient adherence to drug therapy and decrease the degree of therapeutic inertia by healthcare providers."
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By Piriya Mahendra