Evaluation of the effects of nifedipine GITS on the blood pressure parameters in subacute cerebral infarction with essential hypertension by ambulatory blood pressure monitoring

Objective To study the antihypertensive efficacy and influence on the blood pressure parameters of nifedipine GITS therapy in patients with subacute cerebral infarction with essential hypertension by ambulatory blood pressure monitoring (ABPM).Methods Fifty-one cases of subacute cerebral infarction with essential hypertension were treated with nifedipine GITS for 14 days.ABPM were performed in all cases before and after treatment.The blood pressure parameters of blood pressure variability (BPV),morning blood pressure surge(MBPS),Trough/Peak(T/P),and smoothness index(SI) were analyzed.Results (1) After treatment with nifedipine GITS 30 mg/d for two weeks,the average 24-hour systolic blood pressure (SBP),day-time systolic blood pressure (dSBP),night-time systolic blood pressure (nSBP),24-hour diastolic blood pressure (DBP),day-time diastolic blood pressure (dDBP),night-time diastolic blood pressure (nDBP) significantly decreased((144.70 ± 14.89) mm Hg vs (163.10 ± 16.48) mm Hg,(145.67 ± 15.20) mm Hg vs (164.55 ±16.81) mm Hg,(140.85 ± 19.46) mm Hg vs (156.73 ±20.55) mm Hg,(81.24 ±8.88) mm Hg vs(89.49 ± 10.06) mm Hg,(81.25 ±9.40) mm Hg vs (90.18 ± 10.64) mm Hg,(81.34 ± 12.10) mm Hg vs (86.28 ±12.11) mmHg;t=11.01,11.53,5.29,8.71,7.53,2.31;P＜0.05)).(2) Defining the standard deviation(SD) of average blood pressure as the indexes of BPV,the blood pressure variability of systolic blood pressure(SBPV),day-time systolic blood pressure variability (dSBPV),night-time systolic blood pressure (nSBPV) decreased significantly ((16.52 ± 4.38) mm Hg vs (19.78 ± 6.72) mm Hg,(15.45 ± 4.71)mm Hg vs (17.88 ± 7.25)mm Hg,(14.94 ± 5.89) mm Hg vs (19.17 ± 8.27) mm Hg; t =3.38,2.19,2.99 ;P ＜0.05)) and the diastolic blood pressure didn't change.(3) There was negative correlation between smoothness index (SI) and BPV (r =-0.28 ; P ＜ 0.05).(4) The decreases of morning blood pressure surge (MBPS) of SBP was more significant after treatment ((22.65 ± 12.77) mm Hg) than that before treatment ((31.94 ±16.36) mm Hg).(5) The median of T/P ratio calculated by group methods was 0.721 for SBP and 0.676 for DBP,and it was 0.588 ± 0.360 for SBP and 0.628 ± 0.433 for DBP calculated by individual method.The medians of T/P ratio were above 0.5 by both methods.Conclusion It is of great significance to effectively control blood pressure and BPV in patients with stroke.Nifedipine GITS can constantly release medicine;it can lower the blood pressure,and significantly reduce BPV and MBPS. Key words: Blood pressure variability ;  Hypertensin ;  Trough/Peak;  Smoothness index; Nifedipine GITS;  Cerebral infarction;  Ambulatory blood pressure monitoring