when was the first time since 06/16/2105 patient 28443 arterial bp [systolic] was measured/taken?
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 = 28443 ) ) and chartevents.itemid in ( select d_items.itemid from d_items where d_items.label = 'arterial bp [systolic]' and d_items.linksto = 'chartevents' ) and strftime('%y-%m-%d',chartevents.charttime) >= '2105-06-16' order by chartevents.charttime asc limit 1