We systematically retrieved and summarised clinical studies on traditional Chinese medicine (TCM) for the prevention and treatment of essential hypertension (EH) using the evidence map. We aimed to explore the evidence distribution, identify gaps in evidence, and inform on future research priorities. Clinical studies, systematic reviews, guidelines, and pathway studies related to TCM for the prevention and treatment of EH, published between January 2000 and December 2019, were included from databases CNKI, WanFang Data, VIP, PubMed, Embase, and Web of Science. The distribution of evidence was analysed using text descriptions, tables, and graphs. A total of 9,403 articles were included, including 5,920 randomised controlled studies (RCTs), 16 guidelines, expert consensus and path studies, and 139 systematic reviews (SRs). The articles publishing trend increased over time. This study showed that the intervention time of TCM was concentrated at 4–8 weeks, mainly through Chinese herbal medicine (CHM) for the prevention and treatment of elderly hypertension and the complications. A Measurement Tool to Assess Systematic Reviews (AMSTAR) scores of the included reviews ranged from 2 to 10. Most of the SRs had a potentially positive effect (n = 120), mainly in 5–8 score. Primary studies and SRs show potential benefits of TCM in lowering blood pressure, lowering the TCM syndrome and symptom differentiation scores (TCM-SSD scores), improving the total effective rate, and reducing the adverse events. The adjunctive effect of TCM on improving the total effective rate, lowering the blood pressure, lowering the TCM-SSD scores, and lowering the adverse effects was only supported by low-quality evidence in this research. The evidence map was used to show the overall research on TCM for the treatment of EH; however, due to the existing problems of the primary studies, the current research conclusion needs further research with higher quality and standardisation.

Background: Hypertension in the elderly with cognitive impairment has been one of the global health issues. Mild cognitive impairment (MCI) is the state of transition between the normal aging process and cognitive changes of unformed dementia. Diagnosis and treatment of MCI are the keys to prevent dementia, and hypertension is one of the important influencing factors of MCI. Our preclinical experiment found that Yizhi Qingxin Decoction (YQD) could effectively reduce the blood pressure of spontaneously hypertensive rats (SHR), improve their spatial learning and memory abilities in Morris water maze, and play a neuroprotective role. The objective is to estimate the safety and efficacy of YQD (capsules) in the treatment of hypertension in the elderly with MCI (deficiency of kidney essence syndrome) through this study. Methods: According to the random number generated by the block random method, 100 participants will be randomly and equally divided into the treatment group (YQD) or the control group ( Ginkgo biloba extract tablets). The conversion rate of dementia will be used as the main evaluating indicator by the CDR scale. The MoCA scale, MMSE scale, ADCS-MCI-ADL-24 scale, CGIC-KDS scale, and 24-h ambulatory blood pressure will be used as the secondary evaluating indicator. Safety will be evaluated based on specific manifestations of adverse reactions and the incidence of adverse events. Objective: The objective is to estimate the curative effect of YQD (capsules) on hypertension in the elderly with MCI (deficiency of kidney essence syndrome), and to evaluate the safety of its clinical application. Trial registration: Chinese Clinical Trial Registry (ICTRP member): ChiCTR2000030292.