Systolic Strain by Speckle-Tracking Echocardiography Is a Feasible and Sensitive Measure of Right Ventricular Dysfunction in Acute Respiratory Failure Patients on Mechanical Ventilation

Abstract

OBJECTIVES:Right ventricular (RV) dysfunction is common in acute respiratory failure and associated with worse outcomes, but it can be difficult to detect in the ICU setting. Speckle-tracking echocardiography (STE) can identify early changes in RV systolic function and be quantified as systolic strain. We measured the feasibility of RV global longitudinal systolic strain (RV GLS) in respiratory failure patients and its association with clinical outcomes.DESIGN:Retrospective cohort.SETTING:Two tertiary hospital medical ICUs in Providence, RI, from March 2015 to January 2018.PATIENTS:Two hundred twenty-three patients with acute respiratory failure requiring mechanical ventilation (MV) with available echocardiograms.MEASUREMENTS AND MAIN RESULTS:Clinical data were extracted from medical records. RV GLS was measured via STE (TOMTEC, Chicago, IL), along with standard echocardiographic measurements by two independent readers blinded to outcomes. The average age was 65 years (range, 21–90 yr), 121 (54%) were men, and the most common etiology of respiratory failure was pneumonia (n = 83, 37%). The average RV GLS was –16% (sd ± 7). The intraobserver correlation coefficients were 0.78 and 0.94, whereas the interobserver correlation coefficient was 0.61 for RV GLS. In the majority of echocardiograms (n = 178, 80%), all wall segments were tracked appropriately by operator visual inspection. Worse RV GLS was associated with greater hospital mortality (odds ratio, 1.03; 95% CI, 1.00–1.07; p = 0.03), such that every 1% decrement in RV GLS was associated with up to a 7% increase in the risk of death. RV GLS was 90% sensitive for the detection of RV dysfunction compared with tricuspid annular plane systolic excursion.CONCLUSIONS:The measurement of RV GLS by STE in subjects on MV is feasible, reproducible, and sensitive for the detection of RV dysfunction. RV GLS may predict poor outcomes in acute respiratory failure.