Risk assessment and treatment benefit in intensively treated hypertensive patients of the Hypertension Optimal Treatment (HOT) study

Background The Hypertension Optimal Treatment (HOT) Study provided informat ion about cardiovascular events in 18 790 hypertensives, subjected to prono unced blood pressure lowering for a mean of 3.8 years. Methods and Results The HOT Study data have been further analysed after ris k stratification of the patients (1999 World Health Organization and Intern ational Society of Hypertension guidelines criteria): (i) no patients of th e HOT Study were classified as low risk, 50% were classified as medium risk , 20.2% as high risk and 29.8% as very high risk; (ii) incidence of cardiov ascular events in these patients with excellent blood pressure control [92% had diastolic blood pressure (DBP) less than or equal to 90 mmHg] remained proportional to pretreatment risk. The relative risk of very high- versus medium-risk strata was between two and three both when HOT Study patients w ere considered independently of, or within the DBP target group they had be en randomized to; and (iii) event rates in all risk strata were calculated to be much lower (possibly 60% lower) than rates expected from baseline ris k calculated approximately by the Framingham equation. Conclusions The low event rate in HOT Study patients is likely to result fr om pronounced blood pressure lowering, and is not explained by a lower risk profile than in previous controlled trials of antihypertensive treatment. The persistence of a risk gradient despite intensive blood pressure lowerin g suggests a combination of blood pressure control with other strategies of risk correction and the need to initiate antihypertensive therapy before c omplications develop. (C) 2001 Lippincott Williams & Wilkins.