 Group 1: Sequential nephron blockade SNB Group n 40 Group 2: Dual blockade of the RAAS plus bisoprolol DBB Group n 40 Intervention: SNB consists in a progressive increase in sodium depletion. After the administration of a thiazide diuretic chlorthalidone and aldosterone receptor blocker, low doses of furosemide are administered and subsequently amiloride is prescribed to enhance the natriuretic effect. 