Comparison between left ventricular tissue Doppler strain imaging and the sequential organ failure assessment score (SOFA score) in patients with severe sepsis or septic shock

Introduction

The Sequential Organ Failure Assessment (SOFA) score is a widely used method to describe organ dysfunction/failure in critically ill patients. Although the majority of the studies use the SOFA score in outcome research, little is known about its correlation to left ventricular (LV) function in patients with severe sepsis and septic shock. The purpose of this study was to evaluate the correlation of SOFA score and LV function by tissue Doppler imaging in this patient population.

Methods

Sixty patients (ages 66 ± 15, men n = 28) admitted to the ICU with severe sepsis or septic shock were prospectively enrolled. Transthoracic echocardiography was performed within 24 hours of admission to the ICU. We measured the LV end diastolic volume index (LVEDVI), LV end systolic volume index (LVESVI), LV ejection fraction (LVEF), mitral deceleration time of E velocity (Dct) and myocardial tissue Doppler strain imaging profiles at the basal, mid and apical portions of the LV septal wall in the LV apical four-chamber view. On the ICU admission day, the SOFA scores were calculated. Significantly correlated parameters were subjected to linear regression analysis. P < 0.05 was considered significant.

Results

The mean heart rate was 90 ± 17 bpm, mean LV volumes, mean LVEF and mean Dct were within normal limits (LVEDVI; 44.6 ± 15.4 ml/m², LVESVI; 18.7 ± 11.5 ml/m², LVEF; 58.9 ± 15.7%, Dct; 175.8 ± 50.2 ms). The mean peak systolic strain measurements were -16.0 ± 5.0% (basal; -18.1 ± 7.0%, mid; -15.7 ± 5.6%, apical; -14.1 ± 6.6%). The mean SOFA score was 10.8 ± 3.9. Linear regression analysis showed correlation between the SOFA score and LVEF (r = -0.40, P = 0.02), Dct (r = -0.34, P = 0.007), mean septal strain (r = 0.40, P = 0.002), mid-septal strain (r = 0.43, P = 0.0007) and apical septal strain (r = 0.36, P = 0.006).

Conclusions

These results suggest that the higher SOFA score had lower LVEF, lower LV systolic strain and higher LV filling pressure in the patients with severe sepsis or septic shock. An assessment of the left ventricular longitudinal contraction by tissue Doppler strain imaging may serve as a useful tool to evaluate multiple organ failure in this patient population.