title: Meta-analysis of the efficacy and safety of adding an angiotensin receptor blocker (ARB) to a calcium channel blocker (CCB) following ineffective CCB monotherapy.
abstract: BACKGROUND
  We conducted this meta-analysis to systematically review and analyze the clinical benefits of angiotensin receptor blocker (ARB) combined with calcium channel blocker (CCB) following ineffective CCB monotherapy.
  
  
  METHODS
  PubMed was searched for articles published until August 2015. Randomized controlled trials (RCTs) evaluating the clinical benefits of ARB combined with CCB following ineffective CCB monotherapy were included. The primary efficacy endpoint of the studies was normal rate of blood pressure, the secondary efficacy endpoints were the response rate and change in blood pressure from baseline. The safety endpoint of the studies was incidence of adverse events. Differences are expressed as relative risks (RRs) with 95% confidence intervals (CIs) for dichotomous outcomes and weighted mean differences (WMDs) with 95% CIs for continuous outcomes. Heterogeneity across studies was tested by using the I(2) statistic.
  
  
  RESULTS
  Seven RCTs were included and had sample sizes ranging from 185 to 1,183 subjects (total: 3,909 subjects). The pooled analysis showed that the on-target rate of hypertension treatment was significantly higher in the amlodipine + ARB group than in the amlodipine monotherapy group (RR =1.59; 95% CI, 1.31-1.91; P<0.01). The response rate of systolic blood pressure (SBP) (RR =1.28; 95% CI, 1.04-1.58; P<0.01) and diastolic blood pressure (DBP) (RR =1.27; 95% CI, 1.12-1.44; P=0.04) were significantly higher in the amlodipine + ARB group than in the amlodipine monotherapy group. The change in SBP (RR =-3.56; 95% CI, -7.76-0.63; P=0.10) and DBP (RR =-3.03; 95% CI, -6.51-0.45; P=0.09) were higher in hypertensive patients receiving amlodipine + ARB but the difference did not reach statistical significance. ARB + amlodipine treatment carried a lower risk of adverse events relative to amlodipine monotherapy (RR =0.88; 95% CI, 0.80-0.96; P<0.01).
  
  
  CONCLUSIONS
  The results of our meta-analysis demonstrate that adding an ARB to CCB after initial ineffective CCB monotherapy, significantly improved blood pressure control and the percentage of on-target hypertension treatment with significantly reduced incidence of adverse events compared with continued CCB monotherapy.
authors.affiliation: 1 Department of Cardiology, Yangpu Hospital, Tongji University, Shanghai 20090, China ; 2 Graduate School, Dalian Medical University, Dalian 116044, China ; 3 Department of Laboratory Medicine, General Hospital of Ji'nan Military Region, Ji'nan 250031, China ; 4 Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Shanghai 200032, China ; 5 Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China ; 6 Cleveland Clinic, Imaging Institute and Heart&Vascular Institute, Cleveland, USA.
authors.forename: Jin
authors.initials: J
authors.lastname: Ma
authors.affiliation: 1 Department of Cardiology, Yangpu Hospital, Tongji University, Shanghai 20090, China ; 2 Graduate School, Dalian Medical University, Dalian 116044, China ; 3 Department of Laboratory Medicine, General Hospital of Ji'nan Military Region, Ji'nan 250031, China ; 4 Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Shanghai 200032, China ; 5 Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China ; 6 Cleveland Clinic, Imaging Institute and Heart&Vascular Institute, Cleveland, USA.
authors.forename: Xiao-Yan
authors.initials: XY
authors.lastname: Wang
authors.affiliation: 1 Department of Cardiology, Yangpu Hospital, Tongji University, Shanghai 20090, China ; 2 Graduate School, Dalian Medical University, Dalian 116044, China ; 3 Department of Laboratory Medicine, General Hospital of Ji'nan Military Region, Ji'nan 250031, China ; 4 Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Shanghai 200032, China ; 5 Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China ; 6 Cleveland Clinic, Imaging Institute and Heart&Vascular Institute, Cleveland, USA.
authors.forename: Zhi-De
authors.initials: ZD
authors.lastname: Hu
authors.affiliation: 1 Department of Cardiology, Yangpu Hospital, Tongji University, Shanghai 20090, China ; 2 Graduate School, Dalian Medical University, Dalian 116044, China ; 3 Department of Laboratory Medicine, General Hospital of Ji'nan Military Region, Ji'nan 250031, China ; 4 Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Shanghai 200032, China ; 5 Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China ; 6 Cleveland Clinic, Imaging Institute and Heart&Vascular Institute, Cleveland, USA.
authors.forename: Zhi-Rui
authors.initials: ZR
authors.lastname: Zhou
authors.affiliation: 1 Department of Cardiology, Yangpu Hospital, Tongji University, Shanghai 20090, China ; 2 Graduate School, Dalian Medical University, Dalian 116044, China ; 3 Department of Laboratory Medicine, General Hospital of Ji'nan Military Region, Ji'nan 250031, China ; 4 Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Shanghai 200032, China ; 5 Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China ; 6 Cleveland Clinic, Imaging Institute and Heart&Vascular Institute, Cleveland, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Schoenhagen
authors.affiliation: 1 Department of Cardiology, Yangpu Hospital, Tongji University, Shanghai 20090, China ; 2 Graduate School, Dalian Medical University, Dalian 116044, China ; 3 Department of Laboratory Medicine, General Hospital of Ji'nan Military Region, Ji'nan 250031, China ; 4 Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Shanghai 200032, China ; 5 Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China ; 6 Cleveland Clinic, Imaging Institute and Heart&Vascular Institute, Cleveland, USA.
authors.forename: Hao
authors.initials: H
authors.lastname: Wang
keywords: Hypertension; angiotensin receptor antagonists; calcium channel blockers (CCB); drug combinations; meta-analysis