Treating Systolic Hypertension in the Elderly: How Low Should Diastolic BP Go?

March 4, 2010

What is the lowest acceptable diastolic blood pressure (BP) in an elderly patient who is being treated for systolic hypertension?

What is the lowest acceptable diastolic blood pressure (BP) in an elderly patient who is being treated for systolic hypertension?
-- MD

Data from the Systolic Hypertension in Europe (Syst-Eur) Trial can help answer this question. The first phase of the Syst-Eur study,1 which ended in 1997, included 4695 patients 60 years or older with isolated systolic hypertension (a systolic BP of 160 to 219 mm Hg and a diastolic BP of less than 95 mm Hg). The patients were randomly assigned to receive either active therapy (initially with nitrendipine, then with the addition of enalapril or hydrochlorothiazide) or placebo and were followed up for a median of 2 years. In the second phase of the study, all surviving patients received the active therapy regimen and were monitored for 4 more years (1997 to 2001).2

Analysis of both the first- and second-phase data (which represent more than 14,000 patient-years of follow-up) revealed the following:

Non-cardiovascular mortality, but not cardiovascular mortality, was increased in patients with low diastolic BP (less than 70 mm Hg), whether they were receiving active treatment or placebo.
In patients with known coronary heart disease at baseline, low diastolic BP was associated with an increase in cardiovascular events, particularly when the diastolic BP was less than 70 mm Hg during active drug therapy.
In patients without coronary heart disease who were receiving active treatment, diastolic BP values as low as 55 mm Hg appeared to be safe from a cardiovascular standpoint.

This analysis supports the concept that in elderly patients without known coronary heart disease, it is reasonable to pursue pharmacotherapy for isolated systolic hypertension as long as the diastolic BP is at least 55 mm Hg.

--Raymond Townsend, MD
    Professor of Medicine
    University of Pennsylvania School of Medicine
    Philadelphia

References:

REFERENCES:

1.

Staessen JA, Fagard R, Thijs L, et al. The Systolic Hypertension in Europe (Syst-Eur) Trial Investigators. Randomised double-blind comparison of placebo and active treatment for older patients with isolated systolic hypertension.

Lancet.

1997;350:757-764.

2.

Fagard RH, Staessen JA, Thijs L, et al. On-treatment diastolic blood pressure and prognosis in systolic hypertension.

Arch Intern Med.

2007;167:1884-1891.