Limitations
Long-term follow-up in our study was incomplete (87% of the patients included in 2DSPER had long-term follow-up). Long-term follow-up, however, was available in 99% of the patients included in the 6 centers participating in the currents study, thus minimizing selection bias. Given the unequivocal nature of our results (Figure 2), it is highly unlikely that complete follow-up would significantly alter our findings. GLS is dependent on 2D image quality.22,27 In 2DPSER mid-range systems, frequently utilized in the ED, were used. We do not know whether using high-end machines would have significantly improved GLS accuracy and its predictive power. However, only patients with adequate 2D image quality were included in 2DSPER, hence making our findings relevant to everyday practice. Furthermore, GLS did not predict outcome even in the subgroup of patients with optimal 2D echo image quality.