Controlling resistant hypertension.

Resistant hypertension (failure to achieve target blood pressures with three or more antihypertensive drugs including a diuretic) is an important and preventable cause of stroke. Hypertension is highly prevalent in China (>60% of persons above age 65), and only ~6% of hypertensives in China are controlled to target levels. Most strokes occur among persons with resistant hypertension; approximately half of strokes could be prevented by blood pressure control. Reasons for uncontrolled hypertension include (1) non-compliance; (2) consumption of substances that aggravated hypertension, such as excess salt, alcohol, licorice, decongestants and oral contraceptives; (3) therapeutic inertia (failure to intensify therapy when target blood pressures are not achieved); and (4) diagnostic inertia (failure to investigate the cause of resistant hypertension). In China, an additional factor is lack of availability of appropriate antihypertensive therapy in many healthcare settings. Sodium restriction in combination with a diet similar to the Cretan Mediterranean or the DASH (Dietary Approaches to Stop Hypertension) diet can lower blood pressure in proportion to the severity of hypertension. Physiologically individualised therapy for hypertension based on phenotyping by plasma renin activity and aldosterone can markedly improve blood pressure control. Renal hypertension (high renin/high aldosterone) is best treated with angiotensin receptor antagonists; primary aldosteronism (low renin/high aldosterone) is best treated with aldosterone antagonists (spironolactone or eplerenone); and hypertension due to overactivity of the renal epithelial sodium channel (low renin/low aldosterone; Liddle phenotype) is best treated with amiloride. The latter is far more common than most physicians suppose.