C031: “black box hypertension”: A new cardiovascular risk factor?

The goal of the SHEAF study is to determine whether Self Blood Pressure Measurement (SBPM) has a better cardiovascular prognostic value than office blood pressure (OBP) among French elderly (≥60 y) hypertensive patients (pts) followed-up by general practitioners. Baseline OBP has been assessed using a mercury sphygmomanometer (3 consecutive measurements during 2 visits performed 2 weeks apart). SBPM was performed over a 4-day period: every day a series of 3 consecutive measurements was requested in the morning and in the evening using a validated device OMRON 705 CP. The hypertension threshold was 140/90 mmHg for OBP and 135/85 mmHg for SBPM. Pts with office hypertension and SBPM normotension were defined as “white coat” hypertension (WC), pts with SBPM hypertension and office normotension were defined as “black box” hypertension (BB). Pts with both office and SBPM hypertension were called H and pts with both office and SBPM normotension were called N. 5211 pts (70 ± 7 years) with valid SBPM (at least 15 measurements with at least 6 in the morning and 6 in the evening) were included. Baseline OBP levels were 152 ± 17/85 ± 9 mmHg. Baseline SBPM levels were 146 ± 19/82 ± 10 mmHg. The 4 groups of pts are significantly different for the following variables: (See Table) BB n = 539 H n = 3252 WC n = 671 N n = 749 P Men (%) 58.3 52.7 36.4 39.3 0.001 History of coronary disease (%) 13.4 12.7 7.9 12.7 0.004 History of stroke (%) 6.7 4.9 2.7 3.7 0.005 Diabetes (%) 14.5 15.5 12.7 11.1 0.009 Obesity (%) 19.1 20.2 15.3 15.8 0.003 SBP/DBP OBP (mmHg) 135/79 160/88 152/85 131/77 0.0001 SBP/DBP SBPM (mmHg) 144/83 156/86 127/74 123/74 0.0001 Pts with “black box hypertension” have the same cardiovascular profile than pts with hypertension. The follow-up of the SHEAF study will precise the cardiovascular prognosis of these patients.