By: Thomas Pickering, MD, DPhil, FRCP, Director of Integrative and Behavioral Cardiology Program
of the Cardiovascular Institute at Mount Sinai School of Medicine, New York.

Several studies have demonstrated the benefits of treating isolated systolic hypertension of the elderly (usually defined as a systolic pressure above 160 mmHg and a diastolic pressure below 95). The latest in this series is called Syst-China and was undertaken in 1,253 Chinese men and women with systolic hypertension who were aged at least 60. They were randomly allocated to “active” treatment (starting with nitrendipine, a calcium channel blocker, and adding an ACE inhibitor and diuretic as needed), or placebo (inert pills) for a period of three years, to evaluate the impact of treatment on cardiovascular events (principally strokes and heart attacks).

The active treatment lowered the overall rate of cardiovascular events by about one third (33%). The most striking finding was in the patients who had diabetes as well as hypertension (this was only 4% of the total- a much lower rate than would be seen in a western population). Those diabetics who were allocated to the placebo group had a risk of events that was three times higher than those without diabetes, but in the treated group, the risk was the same in the patients with and without diabetes, indicating that the benefits of treatment were much greater in the diabetics than in the non-diabetics (59% versus 33% reduction of risk).

Another finding of interest was that the risk was higher in patients with higher systolic pressures and also lower diastolic pressures, which is consistent with other studies that have shown that a wide pulse pressure (the difference between systolic and diastolic pressure) is a powerful risk factor.

Doctor’s comments

This study confirms the findings of two earlier studies (called SHEP and Syst-Eur) that treating isolated systolic hypertension in older people is very worthwhile. Syst-Eur also used a calcium channel blocker as the initial drug to lower the blood pressure, and also found that the benefits of treatment were greater in diabetics than in non-diabetics. SHEP started with a diuretic and found that the benefits were the same in diabetics and non-diabetics.

Another diuretic-based study (called HDFP), which admittedly did not focus on the elderly, found no extra benefit in diabetics. These considerations led the authors of the Syst-China study to suggest that elderly hypertensives who also have diabetes should have their treatment started with a calcium channel blocker rather than a diuretic, which seems a quite reasonable conclusion. It should be noted that the calcium channel blocker used in both Syst-China and Syst-Eur (nitrendipine) is not available in the US, but Norvasc (amlodipine), Procardia XL (nifedipine), Plendil (felodipine), and Sular (nisoldipine) are all available and from the same class (the dihydropyridines).

Where it was published