Endocrine Abstracts

Introduction: Primary aldosteronism (PA) is a potentially curable cause of hypertension. In 2007, a standardized PA work-up protocol was introduced in Landspitali University Hospital (LUH), a tertiary care center for Iceland. The aim of this study is to review treatment response for patients diagnosed with unilateral and bilateral PA in LUH 2007–2016.

Methods: All charts for PA-patients aged ≥18, diagnosed 2007–2016 in LUH, were retrospectively reviewed. Saline infusion test confirmed diagnosis. Adrenal venous sampling distinguished unilateral (UD) from bilateral disease (BD). Adrenalectomy was offered for UD, otherwise patients were treated with aldosterone antagonists. Yearly follow-up consisted of monitoring blood pressure, serum-potassium and need for hypertension medication (HTM) and potassium supplementation (PS). Wilcoxon rank-sum test was used for comparison.

Results: Sixty-seven patients were diagnosed with PA during the study period; 40 BD and 27 UD. For BD, median systolic blood pressure (mSBP) at diagnosis was 160 (119–204) mmHg compared to 142 (115–189) mmHg at 1-year follow-up, P = 0.0032. At 5-years, mSBP was 145 (121–168) mmHg, lower than at diagnosis (P = 0.012). For UD, mSBP at diagnosis was 167 (104–214) mmHg compared to 141 (111–188) mmHg at 1-year, P = 0.0004. For UD mSBP at 5-years follow-up was 134 (117–184), lower than at diagnosis, P = 0.0005. Median diastolic blood pressure (mDBP) at diagnosis was 91 (64–132) mmHg for BD compared to 85 (41–106) at 1-year follow-up, P = 0.0092. At 5-years, BD mDBP was 89 (65–100) mmHg, P = 0.15 when compared to same group at diagnosis. For UD, mDBP at diagnosis was 102 (57–140) mmHg. At 1-year, UD mDBP was 90 (69–107) mmHg, lower than at diagnosis (P = 0.0076). At 5-years, UD mDBP was 88 (69–100) mmHg, lower than at diagnosis, P = 0.011. Median number of HTM at diagnosis was 3 (1–6) BD and 3 (0–5) UD. At 1-year, median HTM number was 3 (1–5) BD and 2 (0–5) UD. At 5-years, median HTM number was 2 (1–5) BD and 2 (0–6) UD. At diagnosis, 15 BD patients and 13 UD needed PS. Two from each group needed PS at 5-years.

Conclusions: In this nationwide study, we found that approximately 40% of the patients had UD. With specialised treatment, SBP and DBP reduced significantly in both subgroups. The results indicate that during the study period, only the most serious cases of PA were diagnosed as 42% of the patients in this study needed PS at baseline. The study emphasizes the importance of screening for PA in patients in Iceland.