Early Intervention Of Controlled Release Nifedipine On The Mild Hypertension Patients With Increased PWV

Objectives: Hypertension is a common chronic disease which severely impairs human health, it is also one of the most main cardio-cerebrovascular desease risk factors. The treatment of hypertension should utmostly reduce the overall risk of cardiovascular complications and mortality. Therefore, to improve the long-term prognosis of patients, it is important to detcet subclinical target organ damages and apply effective intervention, as well as controlling blood pressure. Arterial stiffness is best characterized by measuring pulse wave velocity(PWV), Age, gender and blood pressure are the major determinants of the PWV. It has been shown that PWV could improve cardiovascular event prediction in models that included standard risk factors. In active intervention for hypertension, especially early intervention, we can test and assess the effect of drug intervention on vascular lesions. According to the literature, several antihypertensive drugs have been shown to improve the arterial compliance including calcium channel blockers(CCB), angiotensin- converting enzyme inhibitors, angiotensin receptor blockers and nitrates. But the cardiovascular protection effect is different as the mechanism of antihypertension drugs. CCB have been one of the most widely used antihypertension agents in the last 20 years, which can lower the rate of cardiovascular events based on their effectiveness in reducing BP levels. Recent studies suggest that CCB improve structural damage of vascular wall. Chronic treatment with calcium channel blockers, may interfere with remodeling of large arteries and decreased arterial stiffness Therefore, vascular protection by calcium channel blockers is not restricted to a prolonged blood pressure modulation. These findings could be relevant for an intervention in augmented vascular stiffness and related cardiovascular risk. The dihydropyridine Ca2+ blocker nifedipine as effectiveness in reducing BP levels and good tolerability has been used in clinical treatment of cardiovascular disease for many years. Studies have shown that nifedipine could decrease the PWV by reducing BP levels, but the large-scale clinical research has not yet been reported in china.The study was undertaken in patients aged 18 to 75 years, who were newly diagnosed mild hypertension with increased brachial-ankle pulse wave velocity(ba PWV), The medical history and symptoms of each subject were confirmed by the consulting doctor. All the patients were gived controlled relase nifedipine(30mg Daily) for 24 weeks, blood pressure, heart rate and ba PWV were measured at baseline time, 2 weeks, 4 weeks, 8 weeks, 12 weeks, 18 weeks and 24 weeks. The aim of this study is to evaluate nifedipine intervention on the arterial stiffness in patients with early hypertension, and whether the improvement of structural vascular lesion by CCB beyond its blood pressure-lowering effects.Methods: From December 2013 to December 2014, total of 60 consecutive subjects were recruited in the second hospital of hebei medical university, who were newly diagnosed mild hypertension with increased PWV. This was a single-center, single-group, prospective, stage Ⅳclinical trail study.The patients(n=60) were treated with controlled release nifedipine(30 mg/day) for 4 weeks, if BP level was below 140/90 mm Hg, then maintain the dose. If 4-weeks treatment with CCB did not reduce BP to the target level, gave the patients controlled release nifedipine(60mg/day) treatment, after 8 weeks if the BP was still over 140/90 mm Hg, the patients would be given clinical routine treatment. In the study the patients were followed up at 2, 4, 8, 12, 18 and 24weeks, the BP and HR were measured during each follow-up. The ba PWV were measured at baseline time, 4, 12 and 24 weeks. Data were processed with SPSS 17.0 software. When data were subject to normal distribution, continuous variables were expressed as the mean value±standard deviation(SD), Count data expressed as percentage, the comparison of ba PWV, blood pressure measured at baseline, 4 weeks, 12 weeks, 24 weeks applied repeated measurement analysis of variance, deltaba PWV0 and delta SBP0, delta DBP0, smoke, drink, CHOL, TG, LDL, HDL, age, gender applied multiple linear regression analysis. P value of <0.05 was considered as statistically significant.Results:(1)These results suggested that the 24-h ABPM was singnificantly decreased after 24 weeks treatment with controlled release nifedipine(P<0.001), The systolic and diastolic blood pressure, mean arterial pressure(MAP), pulse pressure(PP) were both decreased significantly compared to baseline(P<0.001) after 4-weeks, 12-weeks, 24-weeks treatment. There were no significant changes in BP, MAP, PP between 12-weeks, 24-week s treatment and 4-weeks reatment(P>0.05). There were no significant changes in HR after 4-weeks, 12-weeks and 24-weeks treatment compared to baseline(P>0.05).(2) Ba PWV was shortly decreased after the administration of controlled release nifedipine 4 weeks(1587 +/- 213.54cm/s to 1461.15 +/- 174.64 cm/s; P<0.001). Compare to the baseline the ba PWV were also significantly decreased after 12-weeks and 24-weeks treatment(P<0.001); But there were no significant defferences in ba PWV between 4-weeks and 12-weeks treatment, or 12-weeks and 24-week treatment(P>0.05).(3)The ba PWV were correlated with SBP、DBP、MAP(P<0.05),was not correlated with PP(P>0.05).(4)On the multiple linear regression analysis, the deltaba PWV0 was correlated with the delta SBP0、delta DBP0 and delta MAP0(P<0.05). The deltaba PWV0 and delta PP0,smoke, drink, CHO, TG, LDL, HDL, age, gender were not related(P>0.05).Conclusion:The study suggested that with effective reducing BP levels at the same time, ba PWV was significantly decreased shortly after the administration of controlled release nifedipine. Controlled release nifedipine attenuated atherosclerosis, the ba PWV reducing effect of controlled release nifedipine depend on it’s antihypertensive effect.It appeared in the early days, depend on SBP, DBP, MAP.