A new study shows that one-third of patients thought to have resistant high blood pressure (hypertension) actually had “white coat” hypertension – this suggests that when the subject is at a doctor’s appointment their blood pressure elevates, but returns to normal once they have left.
Resistant hypertension occurs when a patient’s blood pressure remains above treatment goals, despite a prescribed dosage of three different types of blood pressure medication. In white coat hypertension, the patient’s blood pressure rises during examinations (hence the term “white coat”), but is normal in everyday life.
The study, reported in the journal Hypertension, used 24-hour ambulatory monitoring to check hypertension patients’ blood pressure at regular intervals under normal living and working conditions.
“Ambulatory monitoring showed that many of these patients’ blood pressures were in the normal range when they were at home or participating in their usual activities,” said Alejandro de la Sierra, M.D., lead author of the study and director of internal medicine at Hospital Mutua Terrassa, University of Barcelona in Spain. He added, “While those who actually had ‘white coat’ hypertension are not risk free, their cardiovascular outcomes are much better.”
The study included 8,295 hypertension patients. Fifty-one percent male, with an average age of 64 years. Testing with 24-hour ambulatory blood pressure monitoring showed that thirty-seven percent of patients previously determined to have resistant hypertension proved to instead have white coat hypertension. The remaining 63 percent had true resistant hypertension.
Researchers took patients’ ambulatory blood pressure every 20 minutes during the day and night and assessed age, gender, weight, height, body mass index, duration of hypertension and known heart risk factors such as smoking, diabetes, lipid profile, electrocardiogram results and clinical cardiovascular disease.
“Those with true resistant hypertension showed high blood pressure at work, during the day and at night,” de la Sierra said. “The true resistant group also was more likely to have blood pressures that abnormally rose during the night when they were sleeping.”
De la Sierra endorses the theory that to rule out white coat hypertension, doctors could use ambulatory monitoring to confirm resistant hypertension in their patients, as it would ensure the most effective treatment options are being utilized. He says, “Patients benefit by knowing whether their blood pressure is normal during daily activities or still needs the reinforcement of dietary and drug measures to achieve the goal.”