Objectives The aim of this systematic review was to assess the antihypertensive efficacy of extended-release nitrate for isolated systolic hypertension in elderly patients.
Methods The electronic databases searched were the Database of Abstracts of Reviews of Effectiveness (DARE), Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, Chinese BioMedical Literature Database, VIP, China National Knowledge Infrastructure, the WHO International Clinical Trials Registry Platform and Sciencepaper Online. All were searched for published, unpublished and ongoing relevant trials. The final electronic retrieval was carried out on 22th Apr, 2012. Hand-searching of Chinese hypertension journal. There was no language or time restriction when searching. Randomised controlled trials (RCTs) aims to detect the effect of the antihypertensive efficacy of extended-release nitrate for isolated systolic hypertension in elderly patients were considered eligible. Majority of patients were at least 65 years old had to have a baseline systolic blood pressure of at least 140 mmHg and a diastolic blood pressure of less than 90 mmHg (diagnosis of isolate systolic hypertension). Patients in the intervention group should receive any kind of extended-release nitrate as monotherapy compared with placebo treatment in the control group. The study identification, data extraction and risk of bias assessment were carried out by two reviewers independently. Any discrepancies between the two reviewers were resolved by discussion or by a third reviewer. A formal pilot-tested data extraction form was adopted for data extraction, and Cochrane Collaboration’s tool for risk of bias assessment was chosen for risk of bias assessment. Meta-analysis, test for heterogeneity, sensitivity analysis and subgroup analysis were planned.
Results Two RCTs included. One had unclear risk of bias and one had high risk of bias. Two RCTs focus on the therapy of isolated systolic hypertension which compared isosorbide dinitrate as monotherapy with placebo. One studies had flawed data. The result of one RCT showed a significant improvement of pulse pressure (P < 0.05). But, Change of pulse pressure (means ± SD) not reported. Statistical analysis shown that could decrease pulse pressure in 8 weeks follow-up (MD -12.00; 95% CI -27.78 to 3.78) with imputed standard deviations according with the handbook. On the other hand, changes of blood pressure (means ± SD) not reported in two RCTs. So, statistical analysis use data of change from baseline was not delivered. The sensitivity analysis also was not delivered. Statistical analysis use data of standard deviation of blood pressure at the end of treatment shown significantly decrease SBP (MD -13.29; 95% CI -20.86, -5.71)
Conclusions At present, there is a lack of evidence to show whether extended-release nitrate has any effect on blood pressure in elderly patients with isolated systolic hypertension. It is not possible to draw conclusions due to the risk of bias of the included studies.