PARASOL study

INTERVENTION: Test drug administration group: Sacubitril/Valsartan is administered orally once daily after breakfast for 10 weeks. Control drug administration group: Amlodipine besylate is administered orally once daily after breakfast for 10 weeks. CONDITION: essential hypertension PRIMARY OUTCOME: Blood pressure change in 24‐hour SBP from baseline to Week 8. SECONDARY OUTCOME: (1)Blood pressure change in 24‐hour SBP from baseline to Week 8.; (2)Blood pressure change in 24‐hour DBP from baseline to Week 8.; (3)Blood pressure change in 24‐hour PP from baseline to Week 8.; (4)Blood pressure change in 24‐hour SBP/DBP on early morning/daytime/nighttime from baseline to Week 8.; (5)Blood pressure change in office blood pressure (SBP, DBP) from baseline to Week 8.; (6)Achievement rate of antihypertensive target at 8 Weeks of administration.; (7)Blood pressure change in nighttime from baseline to Week 8 using a Wrist blood pressure monitor.; (8)ABPM and Wrist blood pressure monitor, comparison of blood pressure values in each measurement.; (9)Number of adverse events and their frequency.; (10)Blood pressure change in office blood pressure (SBP, DBP) from baseline to Week 4. INCLUSION CRITERIA: (1)Patients at the age of 18 to 79 at the time of obtaining consent. (2)Patients with essential hypertension who are 150‐179 mmHg on office systolic blood pressure. (3)Patients who have not taken antihypertensives for 28 days or more before enrollment. (4)Subjects of Wrist blood pressure monitors:Patients with a wrist circumference of 13.5‐21.5 cm.