biostudies-literatureUnknown16(1)Suh JMCardiac arrest in nonagenarian and centenarian ICU patients carries high mortality, yet the prognostic role of early blood pressure (BP) parameters remains unclear. While most studies have examined nadir or average values, the clinical significance of the highest very early systolic (SBP), diastolic (DBP), and mean arterial pressure (MAP) has not previously been investigated. This study aimed to evaluate whether these peak values within the first 24 h carry prognostic importance in this vulnerable population. We conducted a retrospective multicenter cohort study using data from the ANZICS Adult Patient Database (2010-2024), including 219 patients aged ≥ 90 years admitted to the ICU following in-hospital cardiac arrest. The highest SBP, DBP, and MAP values recorded within the first 24 h werScientific reports1937https://www.ebi.ac.uk/biostudies/studies/S-EPMC12804718biostudies-literatureHighest early blood pressure within 24 hours and mortality after in-hospital cardiac arrest in the oldest ICU patients: A binational cohort study.PMC12804718Pilcher DKaralapillai DLee DKKoshy ANJoosten AWoodford SWeinberg LSuh JMYe JfalseHighest early blood pressure within 24 hours and mortality after in-hospital cardiac arrest in the oldest ICU patients: A binational cohort study.Cardiac arrest in nonagenarian and centenarian ICU patients carries high mortality, yet the prognostic role of early blood pressure (BP) parameters remains unclear. While most studies have examined nadir or average values, the clinical significance of the highest very early systolic (SBP), diastolic (DBP), and mean arterial pressure (MAP) has not previously been investigated. This study aimed to evaluate whether these peak values within the first 24 h carry prognostic importance in this vulnerable population. We conducted a retrospective multicenter cohort study using data from the ANZICS Adult Patient Database (2010-2024), including 219 patients aged ≥ 90 years admitted to the ICU following in-hospital cardiac arrest. The highest SBP, DBP, and MAP values recorded within the first 24 h wer2025-01-01T00:00:00Z2025 Dec2026-06-06T14:44:30.452Z2026-06-01T03:07:04.956ZS-EPMC128047184140780210.1038/s41598-025-31676-w