Patients who have been randomized in a prevous clinical trial of telmisartan can participate. Safety will be assessed by physical examinations, vital signs, 12-ECG, laboratory evaluation as well as adverse events. Efficacy will be assessed by supine blood pressure results. The primary objective of this trial is to assess the safety of Telmisartan during open-label, long term treatment. The study will last 2-3 years with 15-20 patients participating.