Society of Hypertension (ESC/ESH) were, respectively, published. 1,2 Both introduced several major novelties that have an important impact on the HTN epidemic worldwide. One of the most important novelties was the change in the definition of HTN by the American guidelines to a blood pressure ≥130/80 mm Hg. The European guidelines, however, maintained the same classification of BP categories and kept the definition of HTN at 140/90 mm Hg and above.The second novelty was in the definition of control. The American guidelines recommended reaching a blood pressure <130/80 mm Hg for all patients, while the European guidelines considered a value of <140/90 mm Hg as adequate, with the goal to reach <130/80 mm Hg in younger patients (<65 years) provided that treatment is well tolerated. The third novelty was the recommendation by both guidelines, to use combination therapy in a single pill, as first-line treatment for patients with blood pressure ≥140/90 mm Hg.In countries outside the USA and Europe, especially in those were no local HTN guidelines are available, cardiac societies are faced with the dilemma of which guidelines to follow. This is especially true in countries such as Lebanon, where cardiologists have received advanced training in either the USA or Europe. Local authorities need to assess the impact of these guidelines on the prevalence and on control rate of HTN. Evaluating the impact of the new guidelines in Lebanon is also important, because it may reflect the situation in several other countries belonging to the same group of upper-middle income countries according to the World Bank classification 3 or in surrounding countries in the Middle East, where the impact of these guidelines has not been evaluated yet. In the two most recent surveys performed in Lebanon, the prevalence of HTN was 31.2% and 35.9%, the treatment rate was 49% and 59%, and the control rate 27% and 29%. 4,5 These surveys have used 140/90 mm Hg as the definition of HTN and an ontreatment blood pressure <140/90 mm Hg as the definition of control. In order to assess the impact of the new AHA/ACC definition of HTN on Lebanon, we re-analyzed data from our survey that was performed in 2012-2013 on 1697 Lebanese citizens aged 21 years and above. 4 The global prevalence of HTN increases from 35.9% to 58% if the new AHA/ACC definition is applied.This is mainly due to reclassification of the majority of individuals who were in the normal or high-normal blood pressure range according to the ESC/ESH classification, into hypertensive (Table 1). The major increase in prevalence occurred in young patients aged 21-34 years, where it more than doubled from 14.8% to 38%. The increase in prevalence using the 2017 AHA/ ACC definition occurred (but less in term of relative increase) in other age brackets, going up from 34.1% to 57.4% for the group of 35-49 years, from 57.6% to 75.5% for the group of 50-65 years and from 73.3% to 84.4% in individuals older than 65 years. We cannot evaluate the proportion of patients with a blood pressure between 130-139/80...