Blood pressure and aortic elastic properties: verapamil SR/trandolapril compared to a metoprolol/hydrochlorothiazide combination therapy

The effects of 2 fixed antihypertensive combination drugs on blood pressure and aortic elastic properties were compared in 2 parallel groups. Twenty-six patients for 6 months received a calcium antagonist plus ACE inhibitor (verapamil SR 180 mg/trandolapril I mg (Vera/Tran)) and 25 patients a β-adrenoceptor antagonist plus diuretic (metoprolol 100 mg/hydrochlorothiazide 12.5 mg (Meto/HCTZ)). In addition to blood pressure (SBP, DBP), carotidofemoral pulse wave velocity (PWV) was assessed non-invasively. Total peripheral resistance (TPR) was determined from cardiac output derived by electrical impedance cardiography. Sitting DBP decreased for -14.4 mmHg following Vera/Tran compared with -9.2 mmHg following Meto/HCTZ (p = 0.02 for difference between treatments). Blood pressure was normalized (i.e. DBP < 90 mmHg) in 69% of patients with Vera/Tran and in 52% with Meto/HCTZ. PWV was lowered with Vera/Tran to a higher extent than with Meto/HCTZ (differences between group means -0.46 to -0.98 m/sec, statistically not significant). Vera/Tran induced a decrease in TPR of about 15% of baseline values, whereas Meto/HCTZ showed no influence. Treatment-related adverse events following Meto/HCTZ were bradycardia and associated symptoms; following Vera/Tran these were cough and edema in I case each. In the Meto/HCTZ group, there were more withdrawals/drop-outs (9/25) than in the Vera/Tran group (2/26). The somewhat more intense reduction in PWV with Vera/Tran is indicative of an increase in aortic elastic properties associated with the more potent decrease in BP. In the present study, the combination of calcium antagonist plus ACE inhibitor was found to be an effective and well tolerated antihypertensive regimen and in these respects appears to have some advantages compared with a combination of β-blocker plus diuretic.