Comparative Effectiveness Research using an intent-to-treat approach in 8 clinics in South Carolina. The investigators will assess 4 efficacious approaches to controlling treatment-resistant hypertension (TRH): Aldosterone Antagonist, Referral to Hypertension Specialist, Renin Treatment-Guided Therapeutics, and combination of Hypertension Specialist and Renin Treatment-Guided Therapeutics. Patients with TRH are evaluated with the BpTRU device for an accurate and representative blood pressure measure on two occasions before entry into the study. Qualitative data from focus group discussions with practice staff, and patient surveys and interviews will provide contextual data to help explain why some interventions are more acceptable and successful than others.

This is Comparative Effectiveness Research conducted in the real world of under-resourced primary care clinics in South Carolina. Four arms of the study are identified with two clinics/arm enrolling and following patients with TRH. The goal is to compare rates of BP control according to American Heart Association guidelines among the 4 arms, along with clinic and patient satisfaction with each approach.

Our hypothesis is that defining pathophysiological mechanisms (e.g. renin treatment-guided therapeutics) with or without referral to a hypertension specialist will improve blood pressure control over adding an aldosterone antagonist in eligible patients or just referring patients to a hypertension specialist.

This mixed-methods design captures medical and qualitative data to not only describe the outcome of blood pressure control, but to assess the impact of the four interventions on staff and patient satisfaction. Key patient data includes demographics, visits, blood pressure values, medications and laboratory data. Focus group discussions with practice staff before and after the study will document early attitudes toward each arm, any practice changes needed to implement each arm and any burdens of the intervention on the practice. Patient surveys and interviews will assess their satisfaction with each intervention along with their experiences in participating in this research project.

Treatment Resistant Hypertension is a common medical condition, and relatively ineffective treatment regimens are a significant contributing factor. The long-term goal is to establish practice and effective approaches for controlling blood pressure and reducing clinical complications and related health disparities.

Inclusion Criteria:

• Clinical diagnosis of Treatment Resistant Hypertension (TRH)
• On three or more hypertensive medications at therapeutic dose
• BpTRU measurement on two occasions of >135/85 without diabetes or chronic kidney disease or BP >125/75 if diabetes and/or chronic kidney disease.
• Mean of >10 BP readings of >135/85 mm mercury for those with no diabetes or chronic kidney disease
• Mean of >10 home BP readings of >125/75 mm mercury for those with diabetes and/or chronic kidney disease.

Exclusion Criteria:

• Less than 18 years of age
• Refuses or incompetent to provide consent
• BP controlled to goal in or outside the clinic
• Symptomatic or significant orthostatic hypotension (<20/10 on standing)
• Life-threatening or severe illness
• Currently on protocol
• Myocardial Infarction or stroke in the past 6 months
• Estimated Glomerular Filtration Rate <50 ml/1.7/min.

De-identified data file is available. Email Suparna Qanungo at MUSC.

The PI was blinded to clinic and group assignment when he conducted the final statistical analysis.