Utilization and outcomes of early respiratory support in 6.5 million acute heart failure hospitalizations

Abstract

Aims: The incidence and outcomes of a requirement for non-invasive ventilation (NIV) or invasive mechanical ventilation (IMV) in acute heart failure (AHF) hospitalization are not clearly established. Thus, we aimed to characterize the incidence and trends in use of IMV and NIV in AHF and to estimate the magnitude of hazard for mortality associated with requiring IMV and NIV in AHF.

Methods and results: We used the National Inpatient Sample (NIS) to identify AHF hospitalizations between 2008 and 2014. The exposure variable of interest was IMV or NIV use within 24 h of hospital admission compared to no respiratory support. We analysed the association between ventilation strategies and in-hospital mortality using Cox proportional hazards models adjusting for demographics and comorbidities. We included 6 534 675 hospitalizations for AHF. Of these, 271 589 (4.16%) included NIV and 51 459 (0.79%) included IMV within the first 24 h of hospitalization and rates of NIV and IMV use increased over time. In-hospital mortality for AHF hospitalizations including NIV was 5.0% and 27% for IMV compared with 2.1% for neither (P < 0.001 for both). In an adjusted model, requirement for NIV was associated with over two-fold higher risk for in-hospital mortality [hazard ratio (HR) 2.10, 95% confidence interval (CI) 2.01-2.19; P < 0.001] and requirement for IMV was associated with over three-fold higher risk for in-hospital mortality (HR 3.39, 95% CI 3.14-3.66; P < 0.001).

Conclusion: Respiratory support is used in many AHF hospitalizations, and AHF patients who require respiratory support are at high risk for in-hospital mortality. Our work should inform prospective intervention trials and quality improvement ventures in this high-risk population.

Keywords: Acute heart failure; Critical care; Mechanical ventilation; Non-invasive ventilation; Respiratory failure.