. Left ventricular ejection fraction is the most commonly used measure describing pumping efficiency, but it is heavily dependent on loading conditions and therefore not well suited to study pathophysiologic changes. The novel concept of echocardiography-derived myocardial work (MyW) overcomes this disadvantage as it is based on left ventricular (LV) pressure-strain loops. We tracked the in-hospital changes of indices of MyW in patients admitted for acute heart failure (AHF) in relation to their recompensation status and explored the prognostic utility of MyW indices METHODS AND RESULTS: . We studied 126 patients admitted for AHF (mean 73±12 years, 37% female, 40% with reduced LVEF<40%), providing pairs of echocardiograms obtained both on hospital admission and prior to discharge. The following MyW indices were derived: global constructive and wasted work (GCW, GWW), and global work index and work efficiency (GWI, GWE). In HFrEF patients with decreasing NT-proBNP levels during hospitalization, GCW and GWI improved significantly, while GWW remained unchanged. In HFpEF patients, GCW and GWI were unchanged; however, in patients with no decrease or eventual increase in NT-proBNP, we observed an increase in GWW. In all patients with AHF, higher values of GWW were associated with a higher risk of death or rehospitalization within six months after discharge (per 10-point increment: HR 1.035, 95%CI 1.005-1.065).
. Our results suggest differential myocardial responses to de- and recompensation depending on the HF phenotype in patients presenting with AHF. GWW predicted 6-month prognosis in these patients regardless of LVEF. Future studies in larger cohorts need to confirm our results and identify determinants of short- and longer-term changes in MyW.

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