Prevalence and Characteristics of Treatment-Resistant Hypertension among Hypertensive Japanese Outpatients

Aims: To retrospectively investigate the prevalence and characteristics of treatment-resistant hypertension (R-HT) among consecutive hypertensive outpatients, since patients with R-HT are candidates for catheter-based renal sympathetic denervation (RD). Methods: Consecutive hypertensive outpatients (n = 999) were recruited in our hospital. R-HT patients who were candidates for RD had clinic systolic blood pressure > 160 mmHg despite taking three or more antihypertensive drugs including at least one diuretics at higher than standard doses. Results: Our survey indicated that only 26 patients (2.6%) were potential candidates for renal denervation. Candidates for RD showed a significantly higher age (P < 0.005), brain natriuretic peptide level (P = 0.0001), urinary albumin/creatinine excretion ratio in spot urine (P < 0.005), pulse wave velocity (P < 0.01), left ventricular end-diastolic diameter (P < 0.005), and interventricular septal thickness (P < 0.005) than the other 973 patients. Candidates for denervation had a significantly lower hemoglobin (P = 0.0001), serum albumin (P < 0.001), eGFR (P < 0.0005), plasma renin activity (P = 0.0001), and plasma aldosterone level (P < 0.005) than other patients, while their urinary sodium/creatinine ratio was higher, indicating that patients with R-HT appeared to have a high salt intake. Conclusion: Our retrospective clinical survey indicated that only 0.5% of Japanese hypertensive outpatients (5/999 patients) were candidates for RD. Therefore, establishment of hypertension cohort network will be essential to recruit R-HT patients for RD.