Pulmonary Effective Arterial Elastance by Echocardiography and Mortality in the Cardiac Intensive Care Unit

Background

Elevated right ventricular systolic pressure (RVSP) is associated with higher mortality in cardiac intensive care unit (CICU) patients. Markers of right ventricular-pulmonary artery (PA) coupling may be superior to RVSP.

Objectives

The authors sought to determine whether effective PA elastance (E_PA, RVSP to stroke volume ratio) and the ratio of pulmonary and systemic elastances (RVSP to systolic blood pressure [SBP] ratio) predicted mortality in a CICU population.

Methods

Mayo Clinic CICU admissions from 2007 to 2018 with available data for E_PA or RVSP/SBP were included. The primary outcome was in-hospital mortality, and predictors of in-hospital mortality were analyzed using multivariable logistic regression.

Results

The included 5,004 unique CICU patients had a median age of 72.2 years; 40.9% were females. The 348 (7.7%) patients who died during hospitalization had higher E_PA (0.75 vs 0.51) and RVSP/SBP ratio (0.44 vs 0.33). Greater values of E_PA (adjusted OR: 1.12 per 0.1 higher, 95% CI: 1.09-1.16) and RVSP/SBP (adjusted OR: 1.18 per 0.1 higher, 95% CI: 1.11-1.25) ratios were incrementally associated with higher severity of illness, more comorbidities, and increased in-hospital mortality. One-year mortality was incrementally higher with increasing values of E_PA (adjusted HR: 1.09 per 0.1 higher, 95% CI: 1.08-1.1) and RVSP/SBP ratio (adjusted HR: 1.09 per 0.1 higher, 95% CI: 1.07-1.1). Both E_PA and RVSP/SBP ratio had higher discrimination than RVSP alone for predicting in-hospital mortality.

Conclusions

Noninvasive echocardiographic E_PA and RVSP/SBP ratio can be used to incrementally prognosticate among CICU patients, and these parameters predict mortality better than RVSP alone.