Estimate in a real life setting, the frequency of masked hypertension (MH) and white coat effect (WCE) in hypertensive patients treated with one or two drugs, in whom the treating physician decided to intensify the treatment due to target blood pressure not reached.Design and method:
The study was prospective and observational, carried out among 174 physicians randomly selected in Tizi-ouzou city (Algeria). Each doctor included between December 2013 and March 2014, 10 consecutive patients with office blood pressure (OBP) superior or equal to 140/90 mmHg despite 1 or 2 medications and in whom he decided to escalate treatment, left on his discretion. After 6 months follow-up, we recorded OBP and 24-hour ambulatory blood pressure (ABP). The MH was defined as OBP inferior to140/90 mmHg and ABP superior or equal to 130/80 mmHg, and the WCE as OBP superior or equal to 140/90 mmHg and ABP inferior to 130/80 mmHg. To estimate the prevalence of MH and WCE with 2% accuracy and 95% confidence, we should include at least 1225 subjects.Results:
After 6 months follow-up, OBP and ABP were available in 1426 patients. The characteristics of the population were: mean age: 57.2 ± 12.3 years; men: 61.4%; diabetes: 37.8%; BMI: 28.7 ± 3.9; dyslipidemia: 40.7%; prior major cardiovascular event: 14.2%; number of drugs per patient: 2.9 ± 1.1. The mean OBP and ABP at 6 months were 149.8 ± 19.6/ 89.4 ± 12.8 mmHg and 138.9 ± 13.7/ 84.7 ± 12.4 mmHg respectively. The prevalence of MH and WCE were 25.3% (CI 95%: 23%–27.6%) and 8.8% (CI 95%: 7.3%–10.3%) respectively. In the 579 apparently controlled patients (OBP inferior to 140/90 mmHg), 62.3% had ABP superior or equal to 130/80 mmHg and require in fact a further treatment intensification. In the 847 patients with seemingly uncontrolled hypertension (OBP superior or equal to 140/90 mmHg), 14.3% had ABP inferior to 130/80 mmHg and no therapeutic changes are actually useful.Conclusions:
Our study suggests the need for a systematic use of ABP measurement in the management of uncontrolled hypertension.