Ho Chau Le Bao, Sanders Sharon, Doust Jenny, Breslin Monique, Reid Christopher M, Nelson Mark Raymond
Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia.
Centre for Research in Evidence-Based Practice, Bond University, Gold Coast, QLD, Australia.
JMIR Res Protoc. 2017 Sep 1;6(9):e177. doi: 10.2196/resprot.8362.
Many national and international guidelines recommend that the initiation of blood pressure (BP)-lowering drug treatment for the primary prevention of cardiovascular disease (CVD) should no longer be based on BP level alone, but on absolute cardiovascular risk. While BP-lowering drug treatment is beneficial in high-risk individuals at any level of elevated BP, clinicians are concerned about legacy effects on patients with low-to-moderate risk and mildly elevated BP who remain "untreated".
We aim to investigate the legacy effect of delayed BP-lowering pharmacotherapy in middle-aged individuals (45-65 years) with mildly elevated BP (systolic BP 140-159 mmHg and/or diastolic BP 90-99 mmHg) stratified by absolute risk for primary prevention of CVD, but particularly in the low-risk (<10% five-year absolute risk) group.
Randomized trials of BP-lowering therapy versus placebo or pretreated subjects in active comparator studies with posttrial follow-up will be identified using a 2-step process. First, randomized trials of BP-lowering therapy will be identified by (1) retrieving the references of trials included in published systematic reviews of BP-lowering therapy, (2) retrieving studies published by the Blood Pressure Lowering Treatment Trialists' Collaboration (BPLTTC), and (3) checking studies referenced in the 1993 World Health Organization/International Society of Hypertension meeting memorandum on BP management. Posttrial follow-up studies will then be identified by forward citation searching the randomized trials identified in step 1 through Web of Science. The search will include randomized controlled trials with at least 1-year in-trial period and a posttrial follow-up phase. Age is the major determinant of absolute cardiovascular risk, so the participants in our review will be restricted to middle-aged adults who are more likely to have a lower cardiovascular risk profile. The primary outcome will be all-cause mortality. Secondary outcomes will include cardiovascular mortality, fatal stroke, fatal myocardial infarction, and death due to heart failure.
The searches for existing systematic reviews and BPLTTC studies were piloted and modified. The study is expected to be completed before June 2018.
The findings of this study will contribute to the body of knowledge concerning the beneficial, neutral, or harmful effects of delayed BP-lowering drug treatment on the primary prevention of CVD in patients with mildly elevated BP and low-to-moderate CVD risk.
PROSPERO International Prospective Register of Systematic Reviews: CRD42017058414; https://www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42017058414 (Archived by WebCite® at http://www.webcitation.org/6t6sa8O2Q).
许多国家和国际指南建议，启动降压药物治疗以预防心血管疾病（CVD）的一级预防不应再仅基于血压水平，而应基于绝对心血管风险。虽然降压药物治疗对任何血压升高水平的高危个体都有益，但临床医生担心对血压轻度升高且风险低至中度的“未治疗”患者产生遗留效应。
我们旨在研究延迟降压药物治疗对血压轻度升高（收缩压140 - 159 mmHg和/或舒张压90 - 99 mmHg）的中年个体（45 - 65岁）的遗留效应，这些个体根据CVD一级预防的绝对风险进行分层，特别是低风险（五年绝对风险<10%）组。
将通过两步法确定降压治疗与安慰剂对比的随机试验或在有试验后随访的活性对照研究中与预处理受试者对比的随机试验。首先，通过以下方式确定降压治疗的随机试验：（1）检索已发表的降压治疗系统评价中纳入试验的参考文献；（2）检索降压治疗试验协作组（BPLTTC）发表的研究；（3）查阅1993年世界卫生组织/国际高血压学会关于血压管理会议备忘录中引用的研究。然后，通过对第一步中确定的随机试验进行Web of Science的正向引用检索来确定试验后随访研究。检索将包括试验期至少为1年且有试验后随访阶段的随机对照试验。年龄是绝对心血管风险的主要决定因素，因此我们综述中的参与者将限于心血管风险较低的中年成年人。主要结局将是全因死亡率。次要结局将包括心血管死亡率、致命性卒中、致命性心肌梗死和因心力衰竭导致的死亡。
对现有系统评价和BPLTTC研究的检索进行了试点和修改。该研究预计在2018年6月前完成。
本研究的结果将有助于了解延迟降压药物治疗对血压轻度升高且CVD风险低至中度的患者CVD一级预防的有益、中性或有害影响。
国际系统评价前瞻性注册库PROSPERO：CRD42017058414；https://www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42017058414（由WebCite®存档于http://www.webcitation.org/6t6sa8O2Q）。
