The aim was to determine whether plasma renin and AS predict the most effective treatment of SP.
Methods:79 patients with RH were included in the study (a mean of 3.4±1.4 drugs per patient including diuretic, ACE-I or an ARB). The plasma AS and active renin concentration (ARC), the plasma aldosterone-to-renin ratio (ARR) were estimated at baseline. After chemical evaluation patients started on SP treatment with a mid-dose 25 mg daily (range 12.5–50 mg). At baseline and after 12 weeks of therapy patients underwent clinic and 24-hour BP measurement, also hematocrit, potassium (K), serum creatinine (C), eGFR were checked.
Results:In patients with RH the ARC varied widely and they were divided into low 46%, normal 29% and high renin 25% subgroups. All groups of patients had similar AS levels. Patients with high renin hypertension (HRH) had significantly worse renal function than patients with low renin (LRH) or normal renin hypertension (NRH), also hematocrit were significantly higher in HRH patients than in patients with LRH and NRH. At baseline in patients with RH was an excellent correlation between ARC and eGFR (P < .001). After SP in whole group, the change from baseline in the clinic BP was -13.4/-6.8 mm Hg (P < .0001 for both) and in 24-hour BP was -10.6/-6.1 mm Hg (P < .001 for both), but patients with HRH showed less efficacy than patients with LRH and NRH (-5.4/-3.1 mm Hg; P < .05 for both) and in 24-hour BP was -4.8/-2.9 mm Hg (P < .05 for both). Moreover, in HRH patients the hematocrit and C levels increased significantly after the start of SP (P<.001; P < .0001 respectively ). By regression analysis in whole group patients RH ARC and AS levels were not associated with the changes in BP, only eGFR was significantly associated with BP change for DBP (0.391, P<.05); in patients with LRH and NRH was a mild relation between the change for SBP and ARR (P<.05 for both), but not for HRH patients.
Conclusion: SP showed additional antihypertensive effect in the whole group of patients with RH, but in patients with HRH was less effective than in patients with LRH and NRH and lead to the worsening of renal function. In the whole group of patients with RH plasma renin and aldosterone levels were not associated with BP response to SP, but the change in DBP was correlated with baseline eGFR. Only in patients with LRH and NRH was a mild association between BP response to SP and ARR. So, we can't treat all RH patients with the help of one universal algorytm and treatment should be tailored to each patient according to neurohumoral profile and renal function.