Observational Study to Investigate the Effectiveness of Eprosartan on Pulse Pressure (Teveten_MS)

Primary Objective -To assess the changes of pulse pressure at 12 weeks Secondary Objectives * To assess the changes of pulse pressure at 4, 24 weeks * To assess the changes of systolic blood pressure and diastolic blood pressure at each visit * Percentage of responder rate\* at each visit and time to get normalized BP from enrollment * Responder rate at last visit * To assess IIEF-5 (5-item Version of the International Index of Erectile Function) score at enrollment and 24 weeks (percentage of patients with ED according to IIEF-5, Changes of IIEF-5 domains) * Percentage of patients with erectile dysfunction (ED) according to IIEF-5 and changes of PP in subgroup (age 65, body mass index (BMI) 23, diabetes mellitus, dyslipidemia, benign prostate hypertrophy) * Analysis of correlation between ED and concomitant disease and concomitant medications in patients who received Eprosartan * Score changes of Framingham 10-year Coronary Heart Disease (CHD) risk at 1st visit, 4th visit * Percentages of Eprosartan monotherapy and multiple antihypertensive therapies at enrollment and last visit * Reason for treatment discontinuation (Inadequate BP control, adverse events, others) * Adverse events * Responder rate: SBP \<140mmHg and DBP \<90mmHg (SBP \<140mmHg and DBP \<85mmHg for patients with diabetes mellitus)