Noninvasive echocardiographic cardiac power output predicts mortality in cardiac intensive care unit patients.

BACKGROUND

Low cardiac power output (CPO), measured invasively, can identify critically ill patients at increased risk of adverse outcomes, including mortality. We sought to determine whether non-invasive, echocardiographic CPO measurement was associated with mortality in cardiac intensive care unit (CICU) patients.

METHODS

Patients admitted to CICU between 2007 and 2018 with echocardiography performed within one day (before or after) admission and who had available data necessary for calculation of CPO were evaluated. Multivariable logistic regression determined the relationship between CPO and adjusted hospital mortality.

RESULTS

A total of 5,585 patients (age of 68.3 ± 14.8 years, 36.7% female) were evaluated with admission diagnoses including acute coronary syndrome (ACS) in 56.7%, heart failure (HF) in 50.1%, cardiac arrest (CA) in 12.2%, shock in 15.5%, and cardiogenic shock (CS) in 12.8%. The mean left ventricular ejection fraction (LVEF) was 47.3 ± 16.2%, and the mean CPO was 1.04 ± 0.37 W. There were 419 in-hospital deaths (7.5%). CPO was inversely associated with the risk of hospital mortality, an association that was consistent among patients with ACS, HF, and CS. On multivariable analysis, higher CPO was associated with reduced hospital mortality (OR 0.960 per 0.1 W, 95CI 0.0.926-0.996, P = .03). Hospital mortality was particularly high in patients with low CPO coupled with reduced LVEF, increased vasopressor requirements, or higher admission lactate.

CONCLUSIONS

Echocardiographic CPO was inversely associated with hospital mortality in unselected CICU patients, particularly among patients with increased lactate and vasopressor requirements. Routine calculation and reporting of CPO should be considered for echocardiograms performed in CICU patients.