Does optimal or normal blood pressure in the office rule out ambulatory hypertension?

Abstract

According to the recommendations of the Sixth Joint National Committee, subjects with office blood pressure (BP) < 140/90 mm Hg are subdivided into groups with high normal BP (130–139 or 85–89 mm Hg), normal BP (< 130/85 mm Hg), and optimal BP (<120/80 mm Hg) based on their risk of cardiovascular disease. Recently, it has been demonstrated that subjects with normal office BP (< 140/90 mm Hg) but ambulatory hypertension (daytime BP ≥ 135/85) have an increased risk of cardiovascular disease. The aim of this study was to find out how many subjects with optimal and normal office blood pressure actually had ambulatory hypertension. Our study population consisted of a random sample of 1700 men and women, age 41–72 years, without major cardiovascular diseases. At baseline, office BP, ambulatory BP, and other risk factors were recorded. In total, 32 subjects with optimal office BP had ambulatory hypertension, and 94 subjects with normal office BP had ambulatory hypertension. Compared with the 1018 subjects with normal ambulatory BP (daytime BP < 135/85), these subjects were younger: mean age 47.9, 51.0, and 53.1 years, respectively. After a mean period of 9.5 years, 156 combined endpoints (cardiovascular death, ischemic heart disease, or stroke) were recorded. The absolute risk of the combined endpoint was 9.4% in subjects with optimal office BP but ambulatory hypertension, 8.3% in subjects with normal office BP but ambulatory hypertension, and 5.6% in subjects with ambulatory normotension (daytime BP < 135/85). In conclusion, optimal and normal office BP does not rule our ambulatory hypertension and an increased risk of cardiovascular disease.