Left Ventricular Ejection Fraction Correlation With Stroke Volume as Estimated by Doppler Echocardiography in Cardiogenic Shock: A Retrospective Observational Study.

ABSTRACT

OBJECTIVES: Echocardiography is the main tool for cardiac assessment and helps to guide management in patients admitted to the intensive care unit (ICU) with cardiogenic shock (CS). Left ventricular ejection fraction (LVEF) is a commonly used echocardiographic surrogate for left ventricular (LV) systolic function. In this hypothesis-generating study, the authors investigated the correlation between LVEF and stroke volume (SV)/SV index (SVI) estimated by Doppler echocardiography in patients admitted to the ICU with CS and reduced LVEF. DESIGN AND SETTING: This retrospective analysis was performed in a single tertiary cardiac center in London, United Kingdom. PARTICIPANTS: Patients admitted to the ICU over a 34-month period with ST elevation myocardial infarction (STEMI) complicated by CS and LVEF <40%. INTERVENTIONS: Clinical and echocardiographic data were collected. LVEF (total, by visual estimate and by modified Simpson's method) was correlated with SV and SVI estimated by Doppler echocardiography. MEASUREMENTS AND MAIN RESULTS: One-hundred patients were included. The mean age was 62.6 ± 12.7 years and 78% were male patients. The median LVEF was 29% (20-35) and the mean SV and SVI by Doppler echocardiography were 47 mL ± 16 and 25 mL ± 9, respectively. Analysis revealed a weak yet statistically significant correlation among LVEF and Doppler SV and SVI (r = 0.44, confidence interval [CI] 0.26-0.60, p < 0.0001, r = 0.47, CI 0.28-0.62, p < 0.001, respectively). Visually estimated LVEF (n = 74) correlated weakly with Doppler SV and SVI yet better compared to LVEF by Simpson's method (n = 25) (r = 0.48, CI 0.27-0.65, p < 0.0001 and r = 0.49, CI 0.28-0.66, p < 0.0001, respectively, v r = 0.36, CI 0.05-0.67, p = 0.08 and r = 0.37, CI -0.04-0.67, p 0.07, respectively). CONCLUSIONS: There is a weak correlation between LVEF and SV or SVI estimated by Doppler echocardiography in patients admitted to the ICU with STEMI complicated by CS and reduced LVEF. Visually estimated LVEF correlated slightly better with Doppler SV compared to modified Simpson's LVEF.