Haemodynamic findings and response rates to beta-blocker--and diuretic monotherapy in mild and moderate hypertension. A one year randomized, double blind study in 100 men.

In a randomized double blind study 100 men (mean age 46 (22-64) years) with mild to moderate hypertension were followed every 3rd month for one year. Fifty were randomized to atenolol 50 mg and 50 to hydrochlorothiazide 25 mg+amiloride 5 mg (co-amiloride) once daily. The doses were doubled at 3 or 6 months if diastolic blood pressure (DBP) remained > or = 95 mmHg. If DBP was > or = 95 mmHg even at 6 or 9 months, patients were classified as non-responders, and nifedipine 20 mg b.i.d. was added. After one year 31/50 randomized to atenolol and 17/50 randomized to co-amiloride had responded to monotherapy (p < 0.05). Neither clinical findings nor haemodynamic measurements by Doppler at baseline could distinguish between co-amiloride responders and non-responders. Conversely, non-responders to atenolol as compared with atenolol responders had higher body weight (p = 0.02), higher systolic BP (p = 0.03), higher DBP (p = 0.009), stroke volume (p = 0.04), and cardiac output (p = 0.0002) combined with lower total systemic vascular resistance (p = 0.02). This suggests that some were apparent non-responders due to too low dosing of atenolol rather than true non-responders. Measurements of haemodynamics may be of importance in the assessment of optimal antihypertensive therapy according to baseline and follow-up haemodynamic aberrations.