It is well known that high blood pressure (HBP, or hypertension) is a major risk factor for adverse cardiovascular events: heart attack, sudden death, and stroke. However, little is known about the relationship between consistency of BP control after such an event, and the risk of subsequent vascular events.
A new study appearing in the journal Stroke (published by the American Heart Association) suggests that keeping blood pressure under control among patients who have had a stroke will likely reduce the risk of a subsequent stroke by over 50 percent. The bad news: fewer than one-in-three stroke victims maintain levels of blood pressure adequately to reduce their risk of further cerebral events.
Researchers led by Dr. Amytis Towfighi of the Keck School of Medicine at USC followed 3,680 stroke survivors, over 35 years of age, during the years 1996-2003. Their blood pressures were measured at baseline and every six months over the two years they were involved in the study, and health outcomes were also recorded. Other risk factors and confounders were controlled for, and blood pressure was considered controlled if it was 140/90 or lower.
They found that among patients with HBP at baseline, those whose BP was controlled 75 percent of the time or more often had a 54 percent lower risk of another stroke as compared to those who had good BP control at less than 25 percent of their medical visits. It s not enough to control blood pressure some of the time. Averages do not take into account variability in blood pressure readings from one check to the next, said Dr. Towfighi. Changes in care management may be needed to ensure patients maintain consistent control of blood pressure. Rather than check blood pressure during clinic visits only, it should done regularly, perhaps at home by machines that can remotely transmit the data, she said. One of the things we really emphasize is getting patients involved in their own care, and learning how to control their risk factors.
ACSH's Dr. Gil Ross added this comment: "It should be easy to follow and treat hypertension in the clinic. Yet it's not: well under 50 percent of people with HBP are adequately treated. HBP is the leading silent killer, so this delivery of healthcare is unacceptable. Of course, patients must be encouraged to check their readings at home: this is not done nearly enough, and I believe would go a long way towards improving this dire situation."