Add-on aliskiren treatment can decrease blood pressure but requires attention to risks of renal impairment and hyperkalemia Chikushi Anti-Hypertension Trial-Rasilez® (CHAT-Ras).

BACKGROUND: Renin is the starting point of the renin angiotensin (RA) system cycle. Aliskiren (AL), which is a direct renin inhibitor, suppressed the entire RA cycle. In the present study, the efficacy of add-on of AL treatment in patients with essential hypertension (HT) was investigated. METHODS: This study was a multi-center, open-label, prospective, observational study. Study subjects were patients with essential HT and poor blood pressure (BP) control, who had received calcium channel blocker monotherapy or angiotensin II receptor blocker monotherapy or had not received any BP lowering drugs. Following add-on of AL for 12 months, BP and additional laboratory findings were analyzed. RESULTS: A total of 150 subjects were enrolled. There were 50 dropout subjects including discontinuation. Dropouts were the highest in the ARB combination therapy group at 9 subjects due to adverse events, and 3 of them were due to hyperkalemia. A significantly higher number of patients with chronic kidney disease (CKD) dropped out compared to patients without CKD (φ = 0.166, p < .05). BP before add-on of AL was 155/88 mmHg. After add-on of AL, BP was significantly improved and this lowering was sustained for 3 months (136/78 mmHg, p < .001), 6 months (136/77 mmHg, p < .001) and 12 months (134/78 mmHg, p < .001). In contrast, add-on of AL increased the potassium level and decreased the estimated glomerular filtration rate. CONCLUSION: While add-on AL treatment achieved a favorable and sustained decrease of BP in this study, caution is necessary with regard to elevation of potassium levels and renal impairment.