THU590 Screening Of Primary Aldosteronism With Low-threshold Criteria In An Outpatient Clinic Setting

Disclosure: M.S. Myint: None. A. Szafran-Swietlik: None. Introduction: Primary aldosteronism (PA) is an underdiagnosed cause of hypertension due to a remarkedly low testing rate. We hypothesized that a lower threshold should be set for testing PA. Hence, we tested for PA in patients with moderate hypertension and compared it to the group that met the Endocrine Society (ES) guideline. Methods: This is a prospective cohort pilot study. Inclusion criteria included hypertension plus any one of the following: (i) age < 40, (ii) use of ≥ 3 antihypertensives, (iii) sleep apnea, (iv) presence of adrenal incidentaloma, (v) hypokalemia, (vi) heart failure without meeting other criteria and (vii) use of 2 antihypertensives without meeting other criteria. Patients were divided into the Standard Group (SG) and the Low-threshold Group (LG). Patients in the SG met one of the standard criteria based on ES guideline (i.e., criteria i through v). Those in the LG met one of our low-threshold criteria vi or vii. Patients were included regardless of their hypertension control. Due to limitations, we did not include 2 criteria: 1) family history of PA and 2) family history of hypertension or stroke before age 40. Patients taking spironolactone were excluded from the study. Patients were pre-screened by chart review. Plasma aldosterone concentration (AC) and plasma renin activity (RA) were ordered during the encounter with the selected patients. The results were followed at their subsequent visits. Those who had a positive plasma aldosterone renin ratio (ARR) of >20 were either marked as “Confirmed Cases” (CC) if they did not require a confirmatory test or marked as “Oral Salt Loading” (OSL) if they required a confirmatory test. Data were analyzed using descriptive study. Results: 793 patients were pre-screened. 149 out of 793 patients met our inclusion criteria. AC and RA were ordered for 105 (70.4%) out of 149 patients. 63 (66.2%) out of 105 patients did the test but 42 patients did not. Among the 63 patients who did the test, 45 fit into the Standard Group. 7 out of 45 patients had positive ARR (15% of SG; 11% of those who did the test) among which 3 were CC and 4 were OSL. In this group, age <40 (n=6), use of ≥3 antihypertensives (n=24), sleep apnea (n=15), adrenal incidentaloma (n=12), and hypokalemia/ borderline hypokalemia (n=6). In the subgroup of the patients taking ≥ 3 antihypertensives, 5 out of 24 patients had positive ARR (11% of SG; 7.9% of those who did the test) among which 3 were CC and 2 were OSL. 18 out of 63 patients fit into our Low-threshold Group. 5 out of 18 patients had positive ARR (27.7% of LG; 7.9% of those who did the test) among which 2 were CC and 3 were OSL. Conclusion: In our study, both the Standard Group (SG) and the Low-threshold group (LG) had a significant number of positive ARR. More research is needed to investigate the prevalence of PA among patients with hypertension regardless of the grade and control of hypertension. A low threshold guideline might improve the rate of testing for PA. Presentation: Thursday, June 15, 2023