To diagnose resistant hypertension using self-measured blood pressure (BP) at home and office BP, and to evaluate the characteristics of resistant hypertensive patients.
The subjects were 528 hypertensive patients taking at least three or more different antihypertensive drugs. Subjects were classified into four groups (controlled hypertension, isolated office resistant hypertension, isolated home resistant hypertension and sustained resistant hypertension) on the basis of the cut-off values of home BP (135/85 mmHg) and office BP (140/90 mmHg). The relationship between each resistant hypertension group and various factors was analysed using univariate and multivariate analyses.
Of the 528 patients, 17.8% were classified with controlled hypertension, 16.1% with isolated office resistant hypertension, 23.5% with isolated home resistant hypertension and 42.6% with sustained resistant hypertension. The presence of hypercholesterolemia was found to have a significant and independent association with isolated office resistant hypertension. Higher office systolic blood pressure (SBP), a past history of ischaemic heart disease, and a lower prescription rate of potassium-sparing diuretics were found to have a significant and independent association with isolated home resistant hypertension. Patients with sustained resistant hypertension had a significantly lower prescription rate of potassium-sparing diuretics than those with controlled hypertension.
The present study demonstrated that resistant hypertension is mediated at least partly by the white-coat effect. Home BP measurements and other relevant factors associated with resistant hypertension, such as relatively higher office SBP, type of drugs prescribed, and cardiovascular complications, should be taken into account for the diagnosis and treatment of resistant hypertension.