Respiratory Support and Mortality Risk Across the Spectrum of Cardiogenic Shock Severity.

Background: The Society for Cardiovascular Angiography & Intervention (SCAI) SHOCK stages classification schema risk-stratifies patients with cardiogenic shock (CS). The updated 2022 SCAI SHOCK stages removed the use of respiratory support, either noninvasive (NIV) or invasive mechanical ventilation (IMV), as a criterion. We sought to investigate the impact of receiving respiratory support on in-hospital mortality for patients with CS stratified by SCAI SHOCK stages. Methods: Utilizing a nationally representative database, adults aged ≥18 years admitted from 2015 to 2023 with a diagnosis of CS were used to assess for the association between respiratory support, either NIV or IMV, on the first day of admission, with in-hospital mortality stratified by SCAI SHOCK stages B through E. We utilized inverse probability treatment weighting, adjusting for demographic characteristics, comorbidities, hospital characteristics, and vasoactive/mechanical circulatory support. Results: We identified 317,325 patients with CS, including 2.4%, 39.0%, 34.2%, and 24.5% with SCAI stages B through E, respectively. Respiratory support was utilized in 38.0% (n = 120,594) of patients, with 5.4% receiving NIV, 33.8% receiving IMV, and 1.1% receiving both on the first day of admission. After inverse probability treatment weighting, respiratory support use remained associated with an increased mortality overall (weighted mean mortality increase of 18.3%; 95% CI, 17.9%-18.7%), when stratified by each SCAI SHOCK stage and in several key sensitivity analyses. Conclusions: Compared with patients not receiving respiratory support, the use of respiratory support was associated with an increased mortality for each SCAI stage of CS and could be a simple, easily identifiable CS risk modifier.