Prevalence of treatment-resistant hypertension after considering pseudo-resistance and morbidity: a cross-sectional study in Irish primary care

Background: To confirm treatment-resistant hypertension (TRH), ambulatory blood pressure measurement (ABPM) must exclude white-coat hypertension (WCH), three or more medications should be prescribed at the optimal doses tolerated, and non-adherence and lifestyle should be examined. Most previous studies have not adequately considered pseudo-resistance and merely provide an apparent TRH (aTRH) prevalence figure.

Aim: To conduct a cross-sectional study of the prevalence of aTRH in general practice, and then consider pseudo-resistance and morbidity.

Design and setting: With support, 16 practices ran an anatomical therapeutic chemical (ATC) drug search, identifying patients on any possible hypertensive medications, and then a search of individual patients' electronic records took place.

Method: ABPM was used to rule out WCH. The World Health Organization-defined daily dosing guidelines determined adequate dosing. Adherence was defined as whether patients requested nine or more repeat monthly prescriptions within the past year.

Results: Sixteen practices participated (n = 50 172), and 646 patients had aTRH. Dosing was adequate in 19% of patients, 84% were adherent to medications, as defined by prescription refill, and 43% had ever had an ABPM. Using a BP cut-off of 140/90 mmHg, the prevalence of aTRH was 9% (95% confidence interval [CI] = 9.0 to 10.0). Consideration of pseudo-resistance further reduced prevalence rates to 3% (95% CI = 3.0 to 4.0).

Conclusion: Reviewing individual patient records results in a lower estimate of prevalence of TRH than has been previously reported. Further consideration for individual patients of pseudo-resistance additionally lowers these estimates, and may be all that is required for management in the vast majority of cases.