when first did patient 12775 have the minimum arterial bp [systolic] on the current icu visit?
select chartevents.charttime from chartevents where chartevents.icustay_id in ( select icustays.icustay_id from icustays where icustays.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 12775 ) and icustays.outtime is null ) and chartevents.itemid in ( select d_items.itemid from d_items where d_items.label = 'arterial bp [systolic]' and d_items.linksto = 'chartevents' ) order by chartevents.valuenum asc, chartevents.charttime asc limit 1