The effect of Chinese herbal medicine combined with western medicine on vascular endothelial function for patients with hypertension Protocol for a systematic review and meta-analysis

Background: Essential hypertension is one of the most common chronic diseases in the world and a major risk factor for cardiovascular and cerebrovascular diseases. Hypertension often leads to a variety of complications, of which vascular endothelial dysfunction is an important part. Traditional Chinese medicine (TCM) combined with western medicine can significantly improve vascular endothelial function in patients with hypertension, but it has not been systematically evaluated for efficacy and safety of essential hypertension. Therefore, we aim to conduct a systematic review and meta-analysis to evaluate the efficacy and safety of TCM combined with western medicine in improving vascular endothelial function in patients with essential hypertension. Methods: Wewill search PubMed, CochraneCentralRegister ofControlled Trials (CENTRAL), ExcerptaMedicaDatabase (EMBASE), China National Knowledge Infrastructure Database (CNKI), Wanfang Database, China Science Journal Database (VIP Database) and China Biomedical Literature Database (CBM). Clinical trial registrations, potential grey literature, related conference abstracts, and reference lists of identified studies will also be retrieved. The electronic database will be searched for literatures published from the beginning toOctober 2018. Based on the heterogeneity test, data integration is performed using a fixed effectmodel or a randomeffects model. Changes in blood pressure and endothelial function will be assessed as primary outcomes. Drug use, disease progression and adverse events will be assessed as secondary outcomes. RevMan V.5.3.5 will be used for meta-analysis. Results: This systematic review and meta-analysis will provide high-quality evidence from a variety of aspects, including efficacy, blood pressure, vascular endothelial function and adverse reactions, to assess the efficacy and safety of TCM combined with western medicine in patients with hypertension. Conclusion: This systematic review will determine whether TCM combined with western medicine provides evidence for effective intervention of vascular endothelial function in patients with essential hypertension.