Of 24 with confirmed PA ( eight unilateral , 11 bilateral , and five undetermined subtype ) , 23 ( 96 % ) tested positive by SSST ( 4-h aldosterone level > 165 pmol/L ) compared with 8 ( 33 % ) by RSST ( 4-h plasma aldosterone level > 140 pmol/L ) ( P < .001 ) .