Efficacy of fludrocortisone for symptom relief in patients with autonomic syncope and hypotensive phenotype

AIM: To assess the efficacy of fludrocortisone therapy in patients with autonomic syncope and hypotensive phenotype. METHODS AND RESULTS: Multicentre, prospective, non-randomized study. Fludrocortisone therapy was guided by clinician experience and supported by two 24-hour ambulatory blood pressure monitoring (ABPM) assessments-one before treatment start (ABPM 1) and one after drug optimization (ABPM 2). Primary endpoint: reduction of the syncope burden and presyncopal symptoms based on validated semi structured questionnaires. Secondary endpoint: hypotensive episodes on ABPM. In a cohort of 94 patients treated with fludrocortisone (median age 38 [IQR 21-57]) years, 83% females), 16 patients stopped therapy due to side effects, occurring during optimization (#11) or follow-up (#5). A total of 83 patients were analysed. The average 24-hour systolic blood pressure (SBP) increased from 106.3 ± 8.2 mmHg at ABPM 1 to 112.3 ± 9.3 at ABPM 2 (p = 0.0001). The number of daytime SBP drops <90 mmHg and <100 mmHg decreased by 61%, and 45% respectively (p < 0.001 for both). The annual syncope burden was reduced by 50.2%, from 2.0 (IQR 1.0-4.0) before therapy to 0.0 (IQR 0.0-1.8) episodes during a median follow-up of 12.9 months (p = 0.0001). Subjective symptom improvement was reported by 85.6% of patients. The frequency of syncope/presyncope decreased significantly, p = 0.009. The outcome was similar in 42 younger (23 ± 6 yrs) and in 41 older (56 ± 12 yrs) patients. CONCLUSION: Fludrocortisone therapy was associated with reduced hypotension and the burden of symptoms both in younger and in older patients. Side effects lead to discontinuation of therapy in 17% of cases.