Angiotensin II for the Treatment of Vasodilatory Shock

To the Editor: In the ATHOS-3 (Angiotensin II for the Treatment of High-Output Shock) trial, Khanna et al. (Aug. 3 issue) 1 report that intravenous angiotensin II effectively increased blood pressure and reduced vasopressor requirements in patients with high-output shock. 1 Angiotensin II, which has a known chronotropic effect, 2 increased the mean heart rate by up to 8% in this trial, as estimated from Figure S3 in the Supplementary Appendix of the article. Given that blood pressure is a function of heart rate, stroke volume, and systemic vascular resistance, 3,4 have the authors considered the relative contribution of this chronotropic, rather than vasopressor, . . .