ObjectiveTo determine whether the decision to treat uncomplicated mild hypertension with drugs, in accordance with the World Health Organization International Society of Hypertension (WHO/ISH) guidelines based on a series of blood pressure (BP) measurements over 6 months, resulted in the treatment of patients at high risk on the basis of echocardiography.MethodsOne hundred and eighteen patients with mild hypertension (diastolic blood pressure 90–105 mmHg and/or systolic blood pressure 140–180 mmHg) were examined by echocardiography at inclusion and followed up for 6 months by a single physician unaware of the echographic results.ResultsDrug treatment was given to 48 patients, and 70 remained untreated. Treated patients had higher echographic indices than untreated patients (allP< 0.05): left ventricular (LV) mass/body surface area (83.0 ± 15.6 versus 75.3 ± 14.8 g/m2), inter-ventricular septal thickness (9.7 ± 1.7 versus 8.5 ± 1.3 mm), LV posterior wall thickness (8.4 ± 1.1 versus 7.8 ± 1.1 mm), relative wall thickness (0.37 ± 0.06 versus 0.34 ± 0.06). LV geometry was normal in 98 patients, and 20 had LV concentric remodelling. The 10-year coronary disease risk (Framingham equation) was higher in the 20 patients with concentric remodelling than in those with normal LV geometry (10.4 versus 4.2%;P< 0.005). Nine of these 20 patients were still untreated at the end of the 6-month follow-up period.ConclusionRigorous application of the WHO/ISH clinical guidelines in a group of mild hypertensive patients led to the treatment of patients with slightly higher LV mass and more concentric LV geometry than were found in those not treated. However, a high-risk subgroup, with concentric remodelling, was not identified and left untreated.