About half of all first-time strokes in patients being treated for high blood pressure result from the pressure not being adequately controlled, Swedish researchers report. Older age, Diabetes, and Smoking also raise the risk of Stroke in these patients.

The study, published in the medical journal Stroke, included nearly 28,000 men and women aged 45 to 73 living in Malmo.

Sixty percent of patients had high blood pressure, but only 23 percent of them were being treated. Moreover, among those receiving treatment, nearly 90 percent had pressures above recommended limits, according to Dr. Cairu Li of Malmo University Hospital and colleagues.

Two-thirds of patients with inadequately controlled blood pressure were on single-drug regimens, the researchers note, with beta-blocker type drugs being the most commonly used overall.

During follow-up, which averaged six years, 137 strokes occurred among the patients with high blood pressure. The researchers found that 45 percent of the stroke risk could be attributed to inadequately controlled blood pressure.

While there were only minor initial differences in survival between patients with controlled or poorly controlled blood pressure, these differences increased over time.

“Adequate (blood pressure) control may prevent a substantial proportion of first-ever stroke among” patients treated for high blood pressure, the researchers conclude.

SOURCE: Stroke, April 1, 2005.