Abstract
Background
Left ventricular (LV) global longitudinal strain has demonstrated incremental prognostic value over LV ejection fraction (LVEF) in patients with ST-segment-elevation acute myocardial infarction. However, LV global longitudinal strain (GLS) does not take into consideration the effect of afterload. Myocardial work (MW) by speckle-tracking echocardiography integrates blood pressure measurements (afterload) with LV GLS and it has been recently demonstrated that Global Work Efficiency (GWE) is associated with long-term all-cause mortality. It remains to be demonstrated if MW indices are associated with hard cardiovascular endpoints. The present study aimed to investigate the prognostic value of global LV MW obtained from pressure-strain loops with echocardiography in patients with ST-segment-elevation myocardial infarction.
Methods
A total of 100 consecutive ST-segment-elevation myocardial infarction patients (mean age, 61±12 years; 75% men) that survived to discharge were retrospectively analysed. LVEF, GLS and all LVMW indices were measured by transthoracic echocardiography before discharge (4.6±2.0 days after admission). All patients had at least a two-year follow-up (mean follow-up of 833±172 days). Outcomes: all-cause mortality, major acute cardiovascular events (a composite of cardiovascular mortality, myocardial infarction, stroke, unplanned cardiovascular admission) and heart failure hospitalization.
Results
In the two-year follow-up, 6 patients died, there were 17 patients with MACE, and 3 patients were hospitalized with heart failure. We confirmed that for all-cause mortality, GWE showed higher discrimination, compared to GLS (Table 1), with a cut-off of 83% (log-rank <0,001). For MACE, the performance of all methods is suboptimal, with an AUC <0.65 for all variables, except for GLS. For heart failure admission, performance is slightly better, but GLS is still the better parameter to predict this event.
Conclusions
LVGWE is a better predictor of all-cause mortality compared to GLS, but MW indices failed to demonstrate a prognostic impact in long-term cardiovascular events. Prospective studies are warranted to confirm this finding.
FUNDunding Acknowledgement
Type of funding sources: None. Table 1
Long-term myocardial functional improvement after autologous bone marrow mononuclear cells transplantation in patients with ST-segment elevation myocardial infarction: 4 years follow-up
