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The following is a summary of “An index of the initial blood pressure response to angiotensin II treatment and its association with clinical outcomes in vasodilatory shock,” published in the February 2025 issue of Critical Care by Leisman et al. 

Researchers conducted a retrospective study to examine whether a standardized index of initial blood pressure response to angiotensin-II treatment was associated with clinical outcomes.  

They utilized data from the Angiotensin Therapy for High Output Shock (ATHOS-3) trial to develop the Angiotensin-II Initial MAP Response Index of Treatment Effect (AIMRITE), calculated as (Mean arterial pressure (MAP) at 1 hr – MAP at baseline)/study drug dose. The AIMRITE was analyzed continuously and categorized based on observed distributions, defining responsiveness as AIMRITE ≥ 0.90 mmHg/ng/kg/min. The primary outcome was 28-day mortality, while secondary outcomes included days alive and free of vasopressor, ventilator, or renal replacement therapy at day 7. Biological outcomes involved baseline renin, angiotensin-II, renin/angiotensin-II ratio, and their changes at 3 hr.  

The results showed that among 158 placebo recipients, 157 (99%) had AIMRITE < 0.90 mmHg/ng/kg/min (median AIMRITE: 0.02; interquartile range [IQR] −0.03–0.10). In contrast, 163 individuals receiving angiotensin-II had a median AIMRITE of 1.43 mmHg/ng/kg/min (IQR 0.35–2.83), with 97 (60%) classified as responsive (median AIMRITE: 2.55; IQR 1.66–4.12) and 66 (40%) as resistant (median AIMRITE: 0.24; IQR 0.10–0.52). Each 1.0-unit increase in AIMRITE correlated with a 16% lower mortality hazard (HR: 0.84 per-mmHg/ng/kg/min [95% CI 0.74–0.95], P = 0.0062). Responsive individuals had a mortality hazard half that of resistant individuals (HR: 0.50 [95% CI 0.32–0.78], P = 0.0026) and placebo recipients (HR: 0.58 [95% CI 0.40–0.86], P = 0.0064), while resistant individuals had a similar mortality hazard to placebo (HR: 1.17 [95% CI 0.80–1.72], P = 0.41). Compared to resistant individuals, responsive individuals had lower baseline renin and renin/angiotensin-II ratio, with a greater reduction in both at 3 hr. Mortality was highest among placebo recipients with high renin (69%) and angiotensin-II resistant individuals with low renin (61%).  

Investigators concluded that AIMRITE was associated with 28-day mortality and could serve as a prognostic indicator to identify individuals most likely to benefit from angiotensin-II treatment. 

Source: ccforum.biomedcentral.com/articles/10.1186/s13054-025-05311-z