Identifying pseudo-resistant hypertension and optimizing diuretic therapy for confirmed resistant cases in primary care

Background: Approximately 10% of individuals with hypertension are expected to have resistant hypertension (RH). Many have pseudo-resistant hypertension (p-RH) due to a variety of factors. To date, the prevalence of p-RH and optimal diuretic therapy in primary care have not been studied. Methods: A retrospective chart review was conducted, including patients referred to the hypertension clinic at the Centre for Family Medicine (CFFM) Family Health Team in Kitchener, ON, from January 2010 to September 2020. Individuals ≥18 years old referred to clinic by their family physician or other health care provider with 2 consecutive blood pressure (BP) readings of ≥140/90 mmHg despite using ≥3 antihypertensive agents were included. Results: Fifty-one patients taking ≥3 antihypertensive agents were referred during the study timeframe. Forty-one patients had ≥2 consecutive BP readings of ≥140/90 and were classified as having presumed RH. Of these, 24 patients (59%) had p-RH after BP was measured systematically in the hypertension clinic. Of the 17 with RH, 5 (29%) were prescribed optimal diuretic therapy upon referral. Most common clinic interventions included initiating or adjusting the dose of a diuretic (47%), adding a different antihypertensive agent (27%) or discontinuing an antihypertensive agent due to side effects (24%). Discussion: To our knowledge, this is the first time that the prevalence of p-RH and optimal diuretic therapy have been studied in primary care. p-RH was common and diuretic therapy was underused in RH. Conclusion: This study suggests that p-RH is prevalent and diuretic therapy underused in primary care. Systematic BP measurement and optimization of diuretic therapy should be prioritized prior to specialist referral.