A Randomized Controlled Study to Assess the Effects of Bisoprolol and Atenolol on Resting Heart Rate and Sympathetic Nervous System's Activity in Subjects With Essential Hypertension

• Change From Baseline in Baroreflex Sensitivity (BRS) at Attainment of Heart Rate Goal [ Time Frame: Baseline and attainment of heart rate goal (Week 2 or Week 4 or Week 6) ] [ Designated as safety issue: No ]
  Baroreflex sensitivity (BRS) is an important characteristic of baroreflex control and often noninvasively assessed by relating heart rate (HR) fluctuations to blood pressure (BP) fluctuations. Heart rate goal was defined as attainment of heart rate less than or equal to 65 beats per minute (bpm).
• Change From Baseline in Baroreflex Sensitivity (BRS) at End of Follow-up [ Time Frame: Baseline and end of follow-up (Week 4 or Week 6 or Week 8) ] [ Designated as safety issue: No ]
  Baroreflex sensitivity (BRS) is an important characteristic of baroreflex control and often noninvasively assessed by relating heart rate (HR) fluctuations to blood pressure (BP) fluctuations. Heart rate goal was defined as attainment of heart rate less than or equal to 65 bpm.

• Change From Baseline in Heart Rate Variability (HRV) for Low Frequency Power (LF) and for High Frequency Power (HF) at Attainment of Heart Rate Goal and End of Follow-up [ Time Frame: Baseline, attainment of heart rate goal (Week 2 or Week 4 or Week 6) and end of follow-up (Week 4 or Week 6 or Week 8) ] [ Designated as safety issue: No ]
  Heart rate variability (HRV) is used to describe the variations of both instantaneous HR and resting rate (RR) intervals and was evaluated for low frequency power (LF) and for high frequency power (HF). Heart rate goal was defined as attainment of heart rate less than or equal to 65 bpm.
• Change From Baseline in Ratio of Heart Rate Variability (HRV) for Low Frequency Power (LF) to Heart Rate Variability Power (HRV) for High Frequency (HF) (LF/HF) at Attainment of Heart Rate Goal and End of Follow-up [ Time Frame: Baseline, attainment of heart rate goal (Week 2 or Week 4 or Week 6) and end of follow-up (Week 4 or Week 6 or Week 8) ] [ Designated as safety issue: No ]
  Heart rate variability (HRV) is used to describe the variations of both instantaneous HR and resting rate (RR) intervals and was evaluated for low frequency power (LF) and for high frequency power (HF). Heart rate goal was defined as attainment of heart rate less than or equal to 65 bpm.
• Number of Participants Attaining Heart Rate Goal at Dosage 1, 2 and 3 of Study Treatment [ Time Frame: Baseline up to attainment of heart rate goal (Week 2 or Week 4 or Week 6) ] [ Designated as safety issue: No ]
  Dosage 1, 2 and 3 for bisoprolol group was defined as 5 mg, 7.5 mg and 10 mg once daily and for atenolol group as 50 mg, 75 mg and 100 mg once daily, respectively. Heart rate goal was defined as attainment of heart rate less than or equal to 65 bpm.
• Percentage of Participants Attaining Heart Rate Goal at Week 2, 4 and 6 [ Time Frame: Attainment of heart rate goal (Week 2 or Week 4 or Week 6) ] [ Designated as safety issue: No ]
  Heart rate goal was defined as attainment of heart rate less than or equal to 65 bpm.
• Number of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs) [ Time Frame: Baseline up to end of follow-up (Week 4 or Week 6 or Week 8) ] [ Designated as safety issue: Yes ]
  AE: any new untoward medical occurrence/worsening of pre-existing medical condition, whether or not related to study drug. SAE: Any AE that resulted in death; was life threatening; resulted in persistent/significant disability/incapacity; resulted in/prolonged an existing in-patient hospitalization; was a congenital anomaly/birth defect; or was a medically important condition
• Number of Participants Compliant With Study Treatment [ Time Frame: Baseline up to end of follow-up (Week 4 or Week 6 or Week 8) ] [ Designated as safety issue: No ]
  Participants compliant with study treatment were the participants who have completed the study treatment regimen.

• Changes of heart rate variability parameters [ Time Frame: Baseline to 1 month after first dose (up to 2 months, if required) ] [ Designated as safety issue: No ]
  To assess the changes of heart rate variability parameters between 2 groups before and after RHR<65bpm including total power (TP), low frequency(LF), high frequency (HF), normalized high frequency (HFn), normalized low frequency (LFn), LF/HF ratio
• Serum concentration in plasma concentration of epinephrine (E) , norepinephrine(NE) , angiotensin-2 II(Ang II) , aldosterone (ALD) and renin activity ( RA) before and after RHR<65bpm in 2 groups [ Time Frame: Baseline to 1 month after first dose (up to 2 months, if required) ] [ Designated as safety issue: No ]
  Assessment of serum concentration in plasma concentration of epinephrine (E), norepinephrine(NE), angiotensin-2 II(Ang II), aldosterone (ALD) and renin activity (RA) before and after RHR<65bpm in 2 groups
• Dosage and duration in days of attaining RHR<65bpm after bisoprolol and atenolol treatment [ Time Frame: 1 month (up to 2 months, if required) ] [ Designated as safety issue: No ]
• Number of participants with adverse events (AE) and serious adverse events (SAE) [ Time Frame: 1 month (up to 2 months, if required) ] [ Designated as safety issue: Yes ]
  Assessment of adverse events (AE) and serious adverse events (SAE) especially the glucose, cholesterol metabolic disfunction or arrhythmia of bisoprolol and atenolol treatment after RHR<65bpm
• Participants compliance for bisoprolol and atenolol treatment after RHR<65bpm [ Time Frame: 1 month (upto 2 months, if required) ] [ Designated as safety issue: No ]
  Total number of tablets taken divided by the total number of tablets to be taken multiplied by 100%

This is a Phase 4, prospective, multi-centric and randomized controlled study to compare the effects of bisoprolol and atenolol on resting heart rate (RHR) and sympathetic nervous system's (SNS) activity in subjects with essential hypertension.

• Drug: Bisoprolol
  Bisoprolol will be administered at a dose of 5 milligram (mg) once daily for 2 weeks. If heart rate is less than or equal to 65 beats per minute (bpm), then the initial dose will be administered for another 2 weeks. If the heart rate remains greater than 65 bpm, then the dose will be further increased to 7.5 mg once daily for 2 weeks. After 2 weeks, if the heart rate is less than or equal to 65 bpm, the increased dose will be administered for another 2 weeks. If the heart rate is still greater than 65 bpm, then the dose will be further increased to 10 mg once daily for 2 weeks. After 2 weeks, if the heart rate is less than or equal to 65 bpm, the increased dose will be administered for another 2 weeks.
  Other Name: Concor®
• Drug: Atenolol
  Atenolol will be administered at a dose of 50 mg once daily for 2 weeks. If heart rate is less than or equal to 65 bpm, then the initial dose will be administered for another 2 weeks. If the heart rate remains greater than 65 bpm, then the dose will be further increased to 75 mg once daily for 2 weeks. After 2 weeks, if the heart rate is less than or equal to 65 bpm, the increased dose will be administered for another 2 weeks. If the heart rate still greater than 65 bpm, then the dose will be further increased to 100 mg once daily for 2 weeks. After 2 weeks, If the heart rate is less than or equal to 65 bpm, the increased dose will be administered for another 2 weeks.

• Experimental: Bisoprolol
  Intervention: Drug: Bisoprolol
• Active Comparator: Atenolol
  Intervention: Drug: Atenolol

Inclusion Criteria:

• Subjects aged between 25-65 years
• Subjects with essential hypertension (EH)
• Subjects with systolic blood pressure (SBP) 140-160 millimeter of mercury (mmHg) and diastolic blood pressure (DBP) 90-100 mmHg
• Subjects with normal sinus rhythm
• Subjects with resting heart rate (RHR) greater than 70 bpm
• Subjects who give written informed consent

Exclusion Criteria:

• Subjects with atrial fibrillation (AF)/sick sinus syndrome (SSS)/atrioventricular block II-III Grade (AVB II-III) without pacemaker
• Subjects with bradyarrhythmia/hypotension
• Subjects with unstable angina pectoris (UAP)/acute myocardial infarction (AMI)/heart failure (HF) (New York Heart Association [NYHA] Class III - IV)
• Subjects with uncontrolled diabetes mellitus (DM)
• Subjects with bronchial asthma
• Subjects with gastro-intestinal ulcer or skin ulcer
• Subjects with liver dysfunction/renal impairment
• Subjects treated with calcium channel blockers (except amlodipine) or other beta-blockers.
• Subjects with glaucoma
• Subjects with known allergic/intolerance to beta-blocker
• Pregnant or lactating women
• Subjects who had participated in another clinical study within the last 3 months
• Subjects who have legal incapacity or limited legal capacity