Myocardial work analysis during semi-supine stress echocardiography: exercise response patterns in heart failure...

Myocardial response to exercise and its differences between heart failure with reduced (HFrEF) and preserved ejection fraction (HFpEF) remain incompletely understood. Myocardial work (MyW) enables a non-invasive assessment of left ventricular performance under physiological stress. We investigated exercise-induced MyW responses in patients with chronic heart failure and healthy controls.

MyStress Pilot study enrolled 24 individuals (12 chronic heart failure patients (6 HFrEF, 6 HFpEF) and 12 healthy controls), aged 40-80 years, who underwent semi-supine exercise stress echocardiography (ESE) using a standardized protocol up to 75 Watt. MyW indices (global work index [GWI], global constructive work [GCW], global wasted work [GWW], global work efficiency [GWE]) were derived using pressure-strain analysis. Linear mixed-effects models assessed workload-dependent changes.Patients with HFrEF and HFpEF were older and achieved lower peak workloads than controls. At rest, GCW was reduced in HFrEF, while GWW was elevated in both heart failure groups. During exercise, controls demonstrated substantial increases in GCW and GWI. In contrast, HFrEF patients exhibited little or no augmentation of GCW and GWI, indicating absent contractile reserve, whereas HFpEF patients showed a blunted increase in GCW accompanied by an abnormal increase in GWW. These differences persisted despite similar systolic blood pressure trajectories across groups, indicating that altered MyW responses were not simply due to afterload. Diastolic parameters increased steeply in HFpEF, unmasking impaired diastolic reserve.

MyW analysis during ESE revealed distinct systolic and diastolic response patterns in heart failure phenotypes and controls. These findings illustrate how pressure-strain analysis can enrich ESE beyond conventional metrics.