Combined antihypertensive and statin therapy for the prevention of cardiovascular events in patients with hypertension without complications: protocol for a systematic review and meta-analysis

INTRODUCTION: High blood pressure (BP) affects over 40% of adults over the age of 25 worldwide and is the leading global risk factor for death or disability. Hypertension is also the most important risk factor for endovascular atherosclerosis, which, when combined with other cardiovascular risk factors, leads to atherosclerotic cardiovascular disease (ASCVD). Statins are one of the most widely used drugs for the prevention of ASCVD. The recently announced study of Heart Outcomes Prevention Evaluation-3 suggests that cholesterol-lowering agents combined with antihypertensive therapy can prevent cardiovascular events and reduce the combined endpoint. We plan to conduct a systematic review and meta-analysis to evaluate whether combined antihypertensive and statin therapy is more beneficial than antihypertensive therapy alone in patients with hypertension without complications. METHODS AND ANALYSIS: We will perform a comprehensive search for randomised controlled trials evaluating combined antihypertensive and statin therapy for the treatment of patients with hypertension. The following English electronic databases will be searched: The Cochrane Library, EMBASE and PubMed. Outcomes will be categorised as short-term (≤6 months) or long-term (>6 months). When evaluating the effects of combined antihypertensive and statin therapy, a short-term outcome is usually defined as a change in BP or lipid levels, while a long-term outcome is usually defined as cardiovascular benefits or risks. The data screening and extraction will be conducted by two different reviewers. The quality of the RCTs will be assessed according to the Cochrane handbook risk of bias tool. ETHICS AND DISSEMINATION: This review does not require ethics approval and the results of the meta-analysis will be submitted to a peer-review journal. PROSPERO REGISTRATION NUMBER: CRD42017071935.