Continuously measuring blood pressure may help predict heart disease and related deaths among individuals with treatment-resistant hypertension, while blood pressure readings taken in a medical office do not appear to predict future heart risks, according to a report in November 24 issue of Archives of Internal Medicine.
About 10 percent to 30 percent of individuals with high blood pressure have a condition known as resistant hypertension, according to background information in the article. For these patients, blood pressure remains high despite treatment with at least three antihypertensive drugs, always including a diuretic (medication that increases urine output). Ambulatory blood pressure monitoring, or measuring blood pressure at regular intervals throughout the day, is increasingly important in managing patients with this condition because of the possibility of a white-coat effect (when an individual only has high blood pressure at the physician's office).
Gil F. Salles, M.D., Ph.D., studied 556 patients with resistant hypertension who attended an outpatient clinic between 1999 and 2004. Participants underwent a clinical examination and had their blood pressure monitored continuously during a 24-hour period (every 15 minutes throughout the day and every 30 minutes at night). They were followed up at least three to four times a year until December 2007.
After a median (midpoint) follow-up period of 4.8 years, 109 (19.6 percent) of participants had a cardiovascular event or died of cardiovascular disease. This included 44 strokes, 21 heart attacks, 10 new cases of heart failure and five sudden deaths. Seventy patients (12.6 percent) died, including 46 (8.3 percent) of cardiovascular causes.