The add-on effect of a Chinese herbal formula for patients with resistant hypertension: study protocol for a pilot cohort study

Despite a recent American Heart Association (AHA) consensus statement emphasizing the importance of resistant hypertension (RH), its control is still a challenge for conventional medicine. The Chinese herbal formula, Qutan Huayu Fang, has been used effectively to assist antihypertensive agents in blood pressure control, but its effect for RH patients is still unclear. This pilot study aims to explore the effects of taking the formula in addition to antihypertensive medication in the management of RH.