Stepwise treatment of uncontrolled HyperTensioN (Stepwise-HTN): Study design of a cluster randomised controlled trial in primary care.

Background: Uncontrolled hypertension is a major health problem, and a key risk factor for cardiovascular disease. Most patients are detected and managed in primary care, but approximately 50% remains uncontrolled. Our aim is to assess whether a guided stepwise work-up management strategy for patients with uncontrolled hypertension in primary care would result in better blood pressure control in these patients compared to usual care.

Methods: A cluster randomised controlled trial aiming at randomizing 40 general practices to either "a protocolised stepwise work-up" or to "usual care". Uncontrolled hypertension is defined as an office blood pressure (BP) >140/90 mmHg while being prescribed three or more antihypertensive drugs simultaneously from different therapeutic classes for three or more months in an adequate dose. In the intervention arm, patients with uncontrolled hypertension will receive the stepwise approach, consisting of (i) excluding a white coat effect, (ii) re-evaluation of lifestyle, (iii) re-evaluation of drug adherence, (iv) optimalisation of antihypertensive treatment and (v) referral if the office BP is still >140/90 mmHg. The control group receives usual care in a regular program for cardiovascular risk management. The primary outcome is the absolute difference in the mean 24-h systolic BP between intervention and control arm after 8 months. Secondary outcomes include differences in the percentage of patients achieving a controlled BP, and time to reach a controlled BP.

Conclusion: If stepwise treatment of uncontrolled hypertension is proven effective, the strategy could be implemented by blending the approach to the cardiovascular risk management already applied in general practice. Trial registration NTR7304, https://www.trialregister.nl/trial/7099.