Abstract 656: Behavior Of Endothelial Function And Blood Pressure After Use Of Spironolactone Or Clonidine In Patients With Resistant Hypertension

Abstract

Objective: To evaluate the behavior of BP and endothelial function after spironolactone or clonidine, associated with optimized antihypertensive treatment in patients with resistant hypertension (PRH). Methods: Prospective and randomized study, visits every 4 weeks. VISIT (V) 0: Inclusion of patients with BP>160/100mmHg and <220mmHg. They receive chlorthalidone 25mg/day and Enalapril 40mg/day or Losartan 100mg/day. V1: If BP>140/90 amlodipine was added 5mg/day. Laboratory evaluation (LE), plasma renin and aldosterone and 20 min ECG, ABPM. V2: If BP>140/90 amlodipine titrated to 10mg/day. V3 (Randomization): ABPM, LE and assessment of endothelial function. If BP>140/90 and/or 24h ABPM>130/80 patients received spironolactone 12.5mg/day or clonidine 0.200mg/day. V4 and V5 (PRH): titration of clonidine (0.200mg to 0.600mg) or spironolactone (12.5mg to 50mg). V6: The same evaluation of V3. Patients with controlled BP in V3 have maintained their medication in V4, V5 and V6 and undergo the same tests that PRH. BP and ABPM was assessed by an automatic device; endothelial function by tonometry arteriolar peripheral (PAT) with Endo-PAT2000 ® and biomarkers (I-CAM, V-CAM, E-sel, PCR); plasma renin and aldosterone by RIA. Results: So far the study evaluated 46 patients where 28 patients had controlled BP and 13 remained resistant. In the spironolactone group the 24h-BP behavior, assessed by ABPM was SBP (V1) 162,8±7,9 and (V6) 124,3±3,7 (p<0,05), DBP (V1) 99,7±5,1 and (V6) 78,2±6,3 (p<0,05); while in the clonidine group SBP (V1) 158,8±11,7 and (V6) 134±19 (p<0,05), DBP (V1) 92±8,4 and (V6) 87,5±13,5 (p<0,05). In the controlled BP group SBP (V1) 134,4±2,7 and (V6) 124,3±3,1 (p<0,05), DBP (V1) 85,2±1,7 and (V6) 78,5±2,5 (p<0,05). The reactive hyperemia index (RHI) determined by the PAT in the spirolactone group was V3: 1,83 ± 0,13 and V6: 1,84 ± 0,2; clonidine group V3: 1,72 ± 0,22 and V6: 1,9 ± 0,6 and controlled BP group V3: 1,87 ± 0,08 and V6: 2,0 ± 0,12. Conclusion: Despite the statistically significant reduction of BP with spironolactone and clonidine, it seems that the improvement in endothelial function has been most pronounced in the clonidine group, although without statistical relevance.