Treatment of Resistant Hypertension: Cohort Study

This is a multicenter, prospective observational cohort study. It will compare effectiveness and safety of various add-on treatment options in regard to arterial blood pressure control in adult patients with treatment resistant hypertension: an aldosterone receptor blocker (e.g. spironolactone), a loop diuretic, a thiazide in large daily dose, an alpha 1 selective blocker or a beta 1 selective blocker. The add-on therapy will be prescribed to the patients within the scope of their routine medical care, independently from the study investigators. Both office and home blood pressure measures will be recorded at baseline and then every month for 6 visits. The systolic and diastolic blood pressure targets are chosen according to European guidelines for treatment of hypertension, i.e. \< 140/90 mmHg. Participants will have contact with the study team at any time to obtain information on interim study outcomes (updated medical history, completion of study questionnaires). Before, during and after the study the patients will be cared for by their chosen general practitioners independently from the study investigators and referred to internal medicine specialists as necessary, according to diagnostic and treatment protocols currently in power at the study sites. Role of the study investigators will be limited to observation and collection of data from the patients themselves and from their medical files.