Restoration of nocturnal dip in blood pressure is associated with improvement in left ventricular ejection fraction.: A 1-year clinical study comparing the effects of Amlodipine and Nifedipine retard on ambulatory blood pressure and left ventricular systo

We assessed the effects of amlodipine and nifedipine retard on 24-h blood pressure (BP) control, nocturnal fall in BP and their significance on left ventricular systolic functions in 54 Chinese hypertensive type 2 diabetic patients. Patients being recruited were openly randomised to amlodipine or nifedipine retard. Ambulatory 24-h BP and echocardiogram (in 42 patients) were measured before and 1 year after treatment. At the end of study, there was 17% reduction in systolic BP; 17% reduction in diastolic BP and 12% reduction in mean arterial pressure (MAP) (no difference between amlodipine and nifedipine). Of the 42 subjects underwent echocardiograms, eight became ‘new-dippers’ at the end of study (non-dippers before treatment and restored nocturnal fall of MAP≥10% after treatment). The other 34 patients were either non-dippers before and after treatment (n=27); dippers before and after treatment (n=3) or dippers before treatment and non-dippers after treatment (n=4). The eight ‘new-dippers’ had improved ejection fraction (69.6±7.2 to 75.8±7.4%, P<0.05) and increased left ventricular diastolic diameter (43.7±7.9 to 47.9±8.8 mm, P<0.05) after the 1-year treatment of calcium antagonist. Compared to the other 34 subjects, the eight ‘new-dippers’ showed significant improvement in ejection fraction (9.4±10.9 vs. −1.2±11.8%, P<0.05). In conclusion, both amlodipine and nifedipine retard are effective in controlling the 24-h BP in Chinese hypertensive type 2 diabetic patients. For those who have restored nocturnal dip in BP have significantly increased left ventricular systolic ejection fraction after 1-year treatment of long acting calcium antagonists. The clinical significance and underlying mechanisms require further studies.