Short- And Long-Term Safety And Efficacy Outcomes Of Spironolactone In Resistant Hypertension

Objective: We aimed to evaluate short- and long-term outcomes of spironolactone as add-on antihypertensive treatment for resistant hypertension (RH). Design and method: We evaluated 202 patients with RH consecutively attended by hypertension specialists, who started spironolactone as additional antihypertensive treatment. Blood pressure and laboratory parameters (serum creatinine (SCrea), estimated glomerular filtration rate by CKD-EPI equation (eGFR) and serum potassium (Kp)) were analysed at 3, 6 and 12 months. Results: The variation of SBP (mean and 95% CI) was −10.7 mmHg [−13.5 to −7.8] and −12.7 mmHg [−15.8 to −9.6] at 3 and 12 months, respectively. The variation of DBP was −4.0 mmHg [−5.6 to −2.3] and −5.4 mmHg [−7.2 to −3.6] at 3 and 12 months. P < 0.001 in all cases. These BP values were confirmed by 24-h ABPM at 12 months, the variation of SBP 24 h was −11.8 mmHg [−17.2 to −6.3] and the variation of DBP was −6.6 mmHg [−9.6 to −3.5] (P < 0.001). The variation of eGFR was −6.4 ml/min/1.73m2 [−9.0 to −3.9] and −9.4 ml/min/1.73m2 [−12.0 to −6.7] at 3 and 12 months, respectively (P < 0.001). The variation of Kp was 1.0 mmol/l [0.2 to 1.8] at 3 months (P = 0.02) and 0.4 mmol/l [−0.5 to 1.2] at 12 months (P = 0.4). The eGFR significantly decreased (p = 0.046) between 3 and 12 months. There were no statistically significant differences in BP, Kp and SCrea between 3 and 12 months. Seventy-seven patients out of the whole cohort were prospectively evaluated. Spironolactone was withdrawn in 7 patients (9.09%) due to adverse effects, including 1 due to excessive eGFR decrease and 1 due to for hyperkalemia. The analysis of the remaining 70 patients parallels the results of the whole cohort. Conclusions: 1) Spironolactone significantly decreased BP at 3 and 12 months. 2) Likewise, we observed a decrease in eGFR at 3 months and 12 months. 3) In 9% of RH patients, spironolactone was withdrawn due to adverse effects. Spironolactone seems a safe and effective add-on treatment for RH, although it requires a close monitoring of renal function.